National Library of Energy BETA

Sample records for adaptive mesh refinement

  1. CLAMR (Compute Language Adaptive Mesh Refinement)

    U.S. Department of Energy (DOE) all webpages (Extended Search)

    CLAMR (Compute Language Adaptive Mesh Refinement) CLAMR (Compute Language Adaptive Mesh Refinement) CLAMR (Compute Language Adaptive Mesh Refinement) is being developed as a DOE...

  2. Parallel Adaptive Mesh Refinement

    SciTech Connect (OSTI)

    Diachin, L; Hornung, R; Plassmann, P; WIssink, A

    2005-03-04

    As large-scale, parallel computers have become more widely available and numerical models and algorithms have advanced, the range of physical phenomena that can be simulated has expanded dramatically. Many important science and engineering problems exhibit solutions with localized behavior where highly-detailed salient features or large gradients appear in certain regions which are separated by much larger regions where the solution is smooth. Examples include chemically-reacting flows with radiative heat transfer, high Reynolds number flows interacting with solid objects, and combustion problems where the flame front is essentially a two-dimensional sheet occupying a small part of a three-dimensional domain. Modeling such problems numerically requires approximating the governing partial differential equations on a discrete domain, or grid. Grid spacing is an important factor in determining the accuracy and cost of a computation. A fine grid may be needed to resolve key local features while a much coarser grid may suffice elsewhere. Employing a fine grid everywhere may be inefficient at best and, at worst, may make an adequately resolved simulation impractical. Moreover, the location and resolution of fine grid required for an accurate solution is a dynamic property of a problem's transient features and may not be known a priori. Adaptive mesh refinement (AMR) is a technique that can be used with both structured and unstructured meshes to adjust local grid spacing dynamically to capture solution features with an appropriate degree of resolution. Thus, computational resources can be focused where and when they are needed most to efficiently achieve an accurate solution without incurring the cost of a globally-fine grid. Figure 1.1 shows two example computations using AMR; on the left is a structured mesh calculation of a impulsively-sheared contact surface and on the right is the fuselage and volume discretization of an RAH-66 Comanche helicopter [35]. Note the

  3. Arbitrary Lagrangian Eulerian Adaptive Mesh Refinement

    Energy Science and Technology Software Center (OSTI)

    2009-09-29

    This is a simulation code involving an ALE (arbitrary Lagrangian-Eulerian) hydrocode with AMR (adaptive mesh refinement) and pluggable physics packages for material strength, heat conduction, radiation diffusion, and laser ray tracing developed a LLNL, UCSD, and Berkeley Lab. The code is an extension of the open source SAMRAI (Structured Adaptive Mesh Refinement Application Interface) code/library. The code can be used in laser facilities such as the National Ignition Facility. The code is alsi being appliedmore » to slurry flow (landslides).« less

  4. COSMOLOGICAL ADAPTIVE MESH REFINEMENT MAGNETOHYDRODYNAMICS WITH ENZO

    SciTech Connect (OSTI)

    Collins, David C.; Xu Hao; Norman, Michael L.; Li Hui; Li Shengtai

    2010-02-01

    In this work, we present EnzoMHD, the extension of the cosmological code Enzo to include the effects of magnetic fields through the ideal magnetohydrodynamics approximation. We use a higher order Godunov method for the computation of interface fluxes. We use two constrained transport methods to compute the electric field from those interface fluxes, which simultaneously advances the induction equation and maintains the divergence of the magnetic field. A second-order divergence-free reconstruction technique is used to interpolate the magnetic fields in the block-structured adaptive mesh refinement framework already extant in Enzo. This reconstruction also preserves the divergence of the magnetic field to machine precision. We use operator splitting to include gravity and cosmological expansion. We then present a series of cosmological and non-cosmological test problems to demonstrate the quality of solution resulting from this combination of solvers.

  5. Visualization Tools for Adaptive Mesh Refinement Data

    SciTech Connect (OSTI)

    Weber, Gunther H.; Beckner, Vincent E.; Childs, Hank; Ligocki,Terry J.; Miller, Mark C.; Van Straalen, Brian; Bethel, E. Wes

    2007-05-09

    Adaptive Mesh Refinement (AMR) is a highly effective method for simulations that span a large range of spatiotemporal scales, such as astrophysical simulations that must accommodate ranges from interstellar to sub-planetary. Most mainstream visualization tools still lack support for AMR as a first class data type and AMR code teams use custom built applications for AMR visualization. The Department of Energy's (DOE's) Science Discovery through Advanced Computing (SciDAC) Visualization and Analytics Center for Enabling Technologies (VACET) is currently working on extending VisIt, which is an open source visualization tool that accommodates AMR as a first-class data type. These efforts will bridge the gap between general-purpose visualization applications and highly specialized AMR visual analysis applications. Here, we give an overview of the state of the art in AMR visualization research and tools and describe how VisIt currently handles AMR data.

  6. Visualization of Scalar Adaptive Mesh Refinement Data

    SciTech Connect (OSTI)

    VACET; Weber, Gunther; Weber, Gunther H.; Beckner, Vince E.; Childs, Hank; Ligocki, Terry J.; Miller, Mark C.; Van Straalen, Brian; Bethel, E. Wes

    2007-12-06

    Adaptive Mesh Refinement (AMR) is a highly effective computation method for simulations that span a large range of spatiotemporal scales, such as astrophysical simulations, which must accommodate ranges from interstellar to sub-planetary. Most mainstream visualization tools still lack support for AMR grids as a first class data type and AMR code teams use custom built applications for AMR visualization. The Department of Energy's (DOE's) Science Discovery through Advanced Computing (SciDAC) Visualization and Analytics Center for Enabling Technologies (VACET) is currently working on extending VisIt, which is an open source visualization tool that accommodates AMR as a first-class data type. These efforts will bridge the gap between general-purpose visualization applications and highly specialized AMR visual analysis applications. Here, we give an overview of the state of the art in AMR scalar data visualization research.

  7. Parallel adaptive mesh refinement for electronic structure calculations

    SciTech Connect (OSTI)

    Kohn, S.; Weare, J.; Ong, E.; Baden, S.

    1996-12-01

    We have applied structured adaptive mesh refinement techniques to the solution of the LDA equations for electronic structure calculations. Local spatial refinement concentrates memory resources and numerical effort where it is most needed, near the atomic centers and in regions of rapidly varying charge density. The structured grid representation enables us to employ efficient iterative solver techniques such as conjugate gradients with multigrid preconditioning. We have parallelized our solver using an object-oriented adaptive mesh refinement framework.

  8. Structured Adaptive Mesh Refinement Application Infrastructure

    Energy Science and Technology Software Center (OSTI)

    2010-07-15

    SAMRAI is an object-oriented support library for structured adaptice mesh refinement (SAMR) simulation of computational science problems, modeled by systems of partial differential equations (PDEs). SAMRAI is developed and maintained in the Center for Applied Scientific Computing (CASC) under ASCI ITS and PSE support. SAMRAI is used in a variety of application research efforts at LLNL and in academia. These applications are developed in collaboration with SAMRAI development team members.

  9. Parallel Block Structured Adaptive Mesh Refinement on Graphics Processing Units

    SciTech Connect (OSTI)

    Beckingsale, D. A.; Gaudin, W. P.; Hornung, R. D.; Gunney, B. T.; Gamblin, T.; Herdman, J. A.; Jarvis, S. A.

    2014-11-17

    Block-structured adaptive mesh refinement is a technique that can be used when solving partial differential equations to reduce the number of zones necessary to achieve the required accuracy in areas of interest. These areas (shock fronts, material interfaces, etc.) are recursively covered with finer mesh patches that are grouped into a hierarchy of refinement levels. Despite the potential for large savings in computational requirements and memory usage without a corresponding reduction in accuracy, AMR adds overhead in managing the mesh hierarchy, adding complex communication and data movement requirements to a simulation. In this paper, we describe the design and implementation of a native GPU-based AMR library, including: the classes used to manage data on a mesh patch, the routines used for transferring data between GPUs on different nodes, and the data-parallel operators developed to coarsen and refine mesh data. We validate the performance and accuracy of our implementation using three test problems and two architectures: an eight-node cluster, and over four thousand nodes of Oak Ridge National Laboratory’s Titan supercomputer. Our GPU-based AMR hydrodynamics code performs up to 4.87× faster than the CPU-based implementation, and has been scaled to over four thousand GPUs using a combination of MPI and CUDA.

  10. Toward parallel, adaptive mesh refinement for chemically reacting flow simulations

    SciTech Connect (OSTI)

    Devine, K.D.; Shadid, J.N.; Salinger, A.G. Hutchinson, S.A.; Hennigan, G.L.

    1997-12-01

    Adaptive numerical methods offer greater efficiency than traditional numerical methods by concentrating computational effort in regions of the problem domain where the solution is difficult to obtain. In this paper, the authors describe progress toward adding mesh refinement to MPSalsa, a computer program developed at Sandia National laboratories to solve coupled three-dimensional fluid flow and detailed reaction chemistry systems for modeling chemically reacting flow on large-scale parallel computers. Data structures that support refinement and dynamic load-balancing are discussed. Results using uniform refinement with mesh sequencing to improve convergence to steady-state solutions are also presented. Three examples are presented: a lid driven cavity, a thermal convection flow, and a tilted chemical vapor deposition reactor.

  11. Advances in Patch-Based Adaptive Mesh Refinement Scalability

    SciTech Connect (OSTI)

    Gunney, Brian T.N.; Anderson, Robert W.

    2015-12-18

    Patch-based structured adaptive mesh refinement (SAMR) is widely used for high-resolution simu- lations. Combined with modern supercomputers, it could provide simulations of unprecedented size and resolution. A persistent challenge for this com- bination has been managing dynamically adaptive meshes on more and more MPI tasks. The dis- tributed mesh management scheme in SAMRAI has made some progress SAMR scalability, but early al- gorithms still had trouble scaling past the regime of 105 MPI tasks. This work provides two critical SAMR regridding algorithms, which are integrated into that scheme to ensure efficiency of the whole. The clustering algorithm is an extension of the tile- clustering approach, making it more flexible and efficient in both clustering and parallelism. The partitioner is a new algorithm designed to prevent the network congestion experienced by its prede- cessor. We evaluated performance using weak- and strong-scaling benchmarks designed to be difficult for dynamic adaptivity. Results show good scaling on up to 1.5M cores and 2M MPI tasks. Detailed timing diagnostics suggest scaling would continue well past that.

  12. Advances in Patch-Based Adaptive Mesh Refinement Scalability

    DOE PAGES-Beta [OSTI]

    Gunney, Brian T.N.; Anderson, Robert W.

    2015-12-18

    Patch-based structured adaptive mesh refinement (SAMR) is widely used for high-resolution simu- lations. Combined with modern supercomputers, it could provide simulations of unprecedented size and resolution. A persistent challenge for this com- bination has been managing dynamically adaptive meshes on more and more MPI tasks. The dis- tributed mesh management scheme in SAMRAI has made some progress SAMR scalability, but early al- gorithms still had trouble scaling past the regime of 105 MPI tasks. This work provides two critical SAMR regridding algorithms, which are integrated into that scheme to ensure efficiency of the whole. The clustering algorithm is an extensionmore » of the tile- clustering approach, making it more flexible and efficient in both clustering and parallelism. The partitioner is a new algorithm designed to prevent the network congestion experienced by its prede- cessor. We evaluated performance using weak- and strong-scaling benchmarks designed to be difficult for dynamic adaptivity. Results show good scaling on up to 1.5M cores and 2M MPI tasks. Detailed timing diagnostics suggest scaling would continue well past that.« less

  13. ENZO: AN ADAPTIVE MESH REFINEMENT CODE FOR ASTROPHYSICS

    SciTech Connect (OSTI)

    Bryan, Greg L.; Turk, Matthew J.; Norman, Michael L.; Bordner, James; Xu, Hao; Kritsuk, Alexei G.; O'Shea, Brian W.; Smith, Britton; Abel, Tom; Wang, Peng; Skillman, Samuel W.; Wise, John H.; Reynolds, Daniel R.; Collins, David C.; Harkness, Robert P.; Kim, Ji-hoon; Kuhlen, Michael; Goldbaum, Nathan; Hummels, Cameron; Collaboration: Enzo Collaboration; and others

    2014-04-01

    This paper describes the open-source code Enzo, which uses block-structured adaptive mesh refinement to provide high spatial and temporal resolution for modeling astrophysical fluid flows. The code is Cartesian, can be run in one, two, and three dimensions, and supports a wide variety of physics including hydrodynamics, ideal and non-ideal magnetohydrodynamics, N-body dynamics (and, more broadly, self-gravity of fluids and particles), primordial gas chemistry, optically thin radiative cooling of primordial and metal-enriched plasmas (as well as some optically-thick cooling models), radiation transport, cosmological expansion, and models for star formation and feedback in a cosmological context. In addition to explaining the algorithms implemented, we present solutions for a wide range of test problems, demonstrate the code's parallel performance, and discuss the Enzo collaboration's code development methodology.

  14. An adaptive mesh-moving and refinement procedure for one-dimensional conservation laws

    SciTech Connect (OSTI)

    Biswas, R.; Flaherty, J.E.; Arney, D.C. Rensselaer Polytech. Inst., Troy, NY Military Acad., West Point, NY )

    1993-01-01

    We examine the performance of an adaptive mesh-moving and /or local mesh refinement procedure for the finite difference solution of one-dimensional hyperbolic systems of conservation laws. Adaptive motion of a base mesh is designed to isolate spatially distinct phenomena, and recursive local refinement of the time step and cells of the stationary or moving base mesh is performed in regions where a refinement indicator exceeds a prescribed tolerance. These adaptive procedures are incorporated into a computer code that includes a MacCormack finite difference scheme wih Davis' artificial viscosity model and a discretization error estimate based on Richardson's extrapolation. Experiments are conducted on three problems in order to qualify the advantages of adaptive techniques relative to uniform mesh computations and the relative benefits of mesh moving and refinement. Key results indicate that local mesh refinement, with and without mesh moving, can provide reliable solutions at much lower computational cost than possible on uniform meshes; that mesh motion can be used to improve the results of uniform mesh solutions for a modest computational effort; that the cost of managing the tree data structure associated with refinement is small; and that a combination of mesh motion and refinement reliably produces solutions for the least cost per unit accuracy.

  15. RAM: a Relativistic Adaptive Mesh Refinement Hydrodynamics Code

    SciTech Connect (OSTI)

    Zhang, Wei-Qun; MacFadyen, Andrew I.; /Princeton, Inst. Advanced Study

    2005-06-06

    The authors have developed a new computer code, RAM, to solve the conservative equations of special relativistic hydrodynamics (SRHD) using adaptive mesh refinement (AMR) on parallel computers. They have implemented a characteristic-wise, finite difference, weighted essentially non-oscillatory (WENO) scheme using the full characteristic decomposition of the SRHD equations to achieve fifth-order accuracy in space. For time integration they use the method of lines with a third-order total variation diminishing (TVD) Runge-Kutta scheme. They have also implemented fourth and fifth order Runge-Kutta time integration schemes for comparison. The implementation of AMR and parallelization is based on the FLASH code. RAM is modular and includes the capability to easily swap hydrodynamics solvers, reconstruction methods and physics modules. In addition to WENO they have implemented a finite volume module with the piecewise parabolic method (PPM) for reconstruction and the modified Marquina approximate Riemann solver to work with TVD Runge-Kutta time integration. They examine the difficulty of accurately simulating shear flows in numerical relativistic hydrodynamics codes. They show that under-resolved simulations of simple test problems with transverse velocity components produce incorrect results and demonstrate the ability of RAM to correctly solve these problems. RAM has been tested in one, two and three dimensions and in Cartesian, cylindrical and spherical coordinates. they have demonstrated fifth-order accuracy for WENO in one and two dimensions and performed detailed comparison with other schemes for which they show significantly lower convergence rates. Extensive testing is presented demonstrating the ability of RAM to address challenging open questions in relativistic astrophysics.

  16. A Predictive Model of Fragmentation using Adaptive Mesh Refinement and a Hierarchical Material Model

    SciTech Connect (OSTI)

    Koniges, A E; Masters, N D; Fisher, A C; Anderson, R W; Eder, D C; Benson, D; Kaiser, T B; Gunney, B T; Wang, P; Maddox, B R; Hansen, J F; Kalantar, D H; Dixit, P; Jarmakani, H; Meyers, M A

    2009-03-03

    Fragmentation is a fundamental material process that naturally spans spatial scales from microscopic to macroscopic. We developed a mathematical framework using an innovative combination of hierarchical material modeling (HMM) and adaptive mesh refinement (AMR) to connect the continuum to microstructural regimes. This framework has been implemented in a new multi-physics, multi-scale, 3D simulation code, NIF ALE-AMR. New multi-material volume fraction and interface reconstruction algorithms were developed for this new code, which is leading the world effort in hydrodynamic simulations that combine AMR with ALE (Arbitrary Lagrangian-Eulerian) techniques. The interface reconstruction algorithm is also used to produce fragments following material failure. In general, the material strength and failure models have history vector components that must be advected along with other properties of the mesh during remap stage of the ALE hydrodynamics. The fragmentation models are validated against an electromagnetically driven expanding ring experiment and dedicated laser-based fragmentation experiments conducted at the Jupiter Laser Facility. As part of the exit plan, the NIF ALE-AMR code was applied to a number of fragmentation problems of interest to the National Ignition Facility (NIF). One example shows the added benefit of multi-material ALE-AMR that relaxes the requirement that material boundaries must be along mesh boundaries.

  17. On the Computation of Integral Curves in Adaptive Mesh Refinement Vector Fields

    SciTech Connect (OSTI)

    Deines, Eduard; Weber, Gunther H.; Garth, Christoph; Van Straalen, Brian; Borovikov, Sergey; Martin, Daniel F.; Joy, Kenneth I.

    2011-06-27

    Integral curves, such as streamlines, streaklines, pathlines, and timelines, are an essential tool in the analysis of vector field structures, offering straightforward and intuitive interpretation of visualization results. While such curves have a long-standing tradition in vector field visualization, their application to Adaptive Mesh Refinement (AMR) simulation results poses unique problems. AMR is a highly effective discretization method for a variety of physical simulation problems and has recently been applied to the study of vector fields in flow and magnetohydrodynamic applications. The cell-centered nature of AMR data and discontinuities in the vector field representation arising from AMR level boundaries complicate the application of numerical integration methods to compute integral curves. In this paper, we propose a novel approach to alleviate these problems and show its application to streamline visualization in an AMR model of the magnetic field of the solar system as well as to a simulation of two incompressible viscous vortex rings merging.

  18. 3D Adaptive Mesh Refinement Simulations of Pellet Injection in Tokamaks

    SciTech Connect (OSTI)

    R. Samtaney; S.C. Jardin; P. Colella; D.F. Martin

    2003-10-20

    We present results of Adaptive Mesh Refinement (AMR) simulations of the pellet injection process, a proven method of refueling tokamaks. AMR is a computationally efficient way to provide the resolution required to simulate realistic pellet sizes relative to device dimensions. The mathematical model comprises of single-fluid MHD equations with source terms in the continuity equation along with a pellet ablation rate model. The numerical method developed is an explicit unsplit upwinding treatment of the 8-wave formulation, coupled with a MAC projection method to enforce the solenoidal property of the magnetic field. The Chombo framework is used for AMR. The role of the E x B drift in mass redistribution during inside and outside pellet injections is emphasized.

  19. Advanced numerical methods in mesh generation and mesh adaptation

    SciTech Connect (OSTI)

    Lipnikov, Konstantine; Danilov, A; Vassilevski, Y; Agonzal, A

    2010-01-01

    Numerical solution of partial differential equations requires appropriate meshes, efficient solvers and robust and reliable error estimates. Generation of high-quality meshes for complex engineering models is a non-trivial task. This task is made more difficult when the mesh has to be adapted to a problem solution. This article is focused on a synergistic approach to the mesh generation and mesh adaptation, where best properties of various mesh generation methods are combined to build efficiently simplicial meshes. First, the advancing front technique (AFT) is combined with the incremental Delaunay triangulation (DT) to build an initial mesh. Second, the metric-based mesh adaptation (MBA) method is employed to improve quality of the generated mesh and/or to adapt it to a problem solution. We demonstrate with numerical experiments that combination of all three methods is required for robust meshing of complex engineering models. The key to successful mesh generation is the high-quality of the triangles in the initial front. We use a black-box technique to improve surface meshes exported from an unattainable CAD system. The initial surface mesh is refined into a shape-regular triangulation which approximates the boundary with the same accuracy as the CAD mesh. The DT method adds robustness to the AFT. The resulting mesh is topologically correct but may contain a few slivers. The MBA uses seven local operations to modify the mesh topology. It improves significantly the mesh quality. The MBA method is also used to adapt the mesh to a problem solution to minimize computational resources required for solving the problem. The MBA has a solid theoretical background. In the first two experiments, we consider the convection-diffusion and elasticity problems. We demonstrate the optimal reduction rate of the discretization error on a sequence of adaptive strongly anisotropic meshes. The key element of the MBA method is construction of a tensor metric from hierarchical edge

  20. A Freestream-Preserving High-Order Finite-Volume Method for Mapped Grids with Adaptive-Mesh Refinement

    SciTech Connect (OSTI)

    Guzik, S; McCorquodale, P; Colella, P

    2011-12-16

    A fourth-order accurate finite-volume method is presented for solving time-dependent hyperbolic systems of conservation laws on mapped grids that are adaptively refined in space and time. Novel considerations for formulating the semi-discrete system of equations in computational space combined with detailed mechanisms for accommodating the adapting grids ensure that conservation is maintained and that the divergence of a constant vector field is always zero (freestream-preservation property). Advancement in time is achieved with a fourth-order Runge-Kutta method.

  1. Refining quadrilateral and brick element meshes

    SciTech Connect (OSTI)

    Schneiders, R.; Debye, J.

    1995-12-31

    We consider the problem of refining unstructured quadrilateral and brick element meshes. We present an algorithm which is a generalization of an algorithm developed by Cheng et. al. for structured quadrilateral element meshes. The problem is solved for the two-dimensional case. Concerning three dimensions we present a solution for some special cases and a general solution that introduces tetrahedral and pyramidal transition elements.

  2. Parallel tetrahedral mesh refinement with MOAB.

    SciTech Connect (OSTI)

    Thompson, David C.; Pebay, Philippe Pierre

    2008-12-01

    In this report, we present the novel functionality of parallel tetrahedral mesh refinement which we have implemented in MOAB. This report details work done to implement parallel, edge-based, tetrahedral refinement into MOAB. The theoretical basis for this work is contained in [PT04, PT05, TP06] while information on design, performance, and operation specific to MOAB are contained herein. As MOAB is intended mainly for use in pre-processing and simulation (as opposed to the post-processing bent of previous papers), the primary use case is different: rather than refining elements with non-linear basis functions, the goal is to increase the number of degrees of freedom in some region in order to more accurately represent the solution to some system of equations that cannot be solved analytically. Also, MOAB has a unique mesh representation which impacts the algorithm. This introduction contains a brief review of streaming edge-based tetrahedral refinement. The remainder of the report is broken into three sections: design and implementation, performance, and conclusions. Appendix A contains instructions for end users (simulation authors) on how to employ the refiner.

  3. Cubit Adaptive Meshing Algorithm Library

    Energy Science and Technology Software Center (OSTI)

    2004-09-01

    CAMAL (Cubit adaptive meshing algorithm library) is a software component library for mesh generation. CAMAL 2.0 includes components for triangle, quad and tetrahedral meshing. A simple Application Programmers Interface (API) takes a discrete boundary definition and CAMAL computes a quality interior unstructured grid. The triangle and quad algorithms may also import a geometric definition of a surface on which to define the grid. CAMAL’s triangle meshing uses a 3D space advancing front method, the quadmore » meshing algorithm is based upon Sandia’s patented paving algorithm and the tetrahedral meshing algorithm employs the GHS3D-Tetmesh component developed by INRIA, France.« less

  4. Software abstractions and computational issues in parallel structure adaptive mesh methods for electronic structure calculations

    SciTech Connect (OSTI)

    Kohn, S.; Weare, J.; Ong, E.; Baden, S.

    1997-05-01

    We have applied structured adaptive mesh refinement techniques to the solution of the LDA equations for electronic structure calculations. Local spatial refinement concentrates memory resources and numerical effort where it is most needed, near the atomic centers and in regions of rapidly varying charge density. The structured grid representation enables us to employ efficient iterative solver techniques such as conjugate gradient with FAC multigrid preconditioning. We have parallelized our solver using an object- oriented adaptive mesh refinement framework.

  5. Curved Mesh Correction And Adaptation Tool to Improve COMPASS Electromagnetic Analyses

    SciTech Connect (OSTI)

    Luo, X.; Shephard, M.; Lee, L.Q.; Ng, C.; Ge, L.; /SLAC

    2011-11-14

    SLAC performs large-scale simulations for the next-generation accelerator design using higher-order finite elements. This method requires using valid curved meshes and adaptive mesh refinement in complex 3D curved domains to achieve its fast rate of convergence. ITAPS has developed a procedure to address those mesh requirements to enable petascale electromagnetic accelerator simulations by SLAC. The results demonstrate that those correct valid curvilinear meshes can not only make the simulation more reliable but also improve computational efficiency up to 30%. This paper presents a procedure to track moving adaptive mesh refinement in curved domains. The procedure is capable of generating suitable curvilinear meshes to enable large-scale accelerator simulations. The procedure can generate valid curved meshes with substantially fewer elements to improve the computational efficiency and reliability of the COMPASS electromagnetic analyses. Future work will focus on the scalable parallelization of all steps for petascale simulations.

  6. Mesh refinement for uncertainty quantification through model reduction

    SciTech Connect (OSTI)

    Li, Jing Stinis, Panos

    2015-01-01

    We present a novel way of deciding when and where to refine a mesh in probability space in order to facilitate uncertainty quantification in the presence of discontinuities in random space. A discontinuity in random space makes the application of generalized polynomial chaos expansion techniques prohibitively expensive. The reason is that for discontinuous problems, the expansion converges very slowly. An alternative to using higher terms in the expansion is to divide the random space in smaller elements where a lower degree polynomial is adequate to describe the randomness. In general, the partition of the random space is a dynamic process since some areas of the random space, particularly around the discontinuity, need more refinement than others as time evolves. In the current work we propose a way to decide when and where to refine the random space mesh based on the use of a reduced model. The idea is that a good reduced model can monitor accurately, within a random space element, the cascade of activity to higher degree terms in the chaos expansion. In turn, this facilitates the efficient allocation of computational sources to the areas of random space where they are more needed. For the Kraichnan–Orszag system, the prototypical system to study discontinuities in random space, we present theoretical results which show why the proposed method is sound and numerical results which corroborate the theory.

  7. Adaptive h -refinement for reduced-order models: ADAPTIVE h -refinement for reduced-order models

    DOE PAGES-Beta [OSTI]

    Carlberg, Kevin T.

    2014-11-05

    Our work presents a method to adaptively refine reduced-order models a posteriori without requiring additional full-order-model solves. The technique is analogous to mesh-adaptive h-refinement: it enriches the reduced-basis space online by ‘splitting’ a given basis vector into several vectors with disjoint support. The splitting scheme is defined by a tree structure constructed offline via recursive k-means clustering of the state variables using snapshot data. This method identifies the vectors to split online using a dual-weighted-residual approach that aims to reduce error in an output quantity of interest. The resulting method generates a hierarchy of subspaces online without requiring large-scale operationsmore » or full-order-model solves. Furthermore, it enables the reduced-order model to satisfy any prescribed error tolerance regardless of its original fidelity, as a completely refined reduced-order model is mathematically equivalent to the original full-order model. Experiments on a parameterized inviscid Burgers equation highlight the ability of the method to capture phenomena (e.g., moving shocks) not contained in the span of the original reduced basis.« less

  8. Applications of automatic mesh generation and adaptive methods in computational medicine

    SciTech Connect (OSTI)

    Schmidt, J.A.; Macleod, R.S.; Johnson, C.R.; Eason, J.C.

    1995-12-31

    Important problems in Computational Medicine exist that can benefit from the implementation of adaptive mesh refinement techniques. Biological systems are so inherently complex that only efficient models running on state of the art hardware can begin to simulate reality. To tackle the complex geometries associated with medical applications we present a general purpose mesh generation scheme based upon the Delaunay tessellation algorithm and an iterative point generator. In addition, automatic, two- and three-dimensional adaptive mesh refinement methods are presented that are derived from local and global estimates of the finite element error. Mesh generation and adaptive refinement techniques are utilized to obtain accurate approximations of bioelectric fields within anatomically correct models of the heart and human thorax. Specifically, we explore the simulation of cardiac defibrillation and the general forward and inverse problems in electrocardiography (ECG). Comparisons between uniform and adaptive refinement techniques are made to highlight the computational efficiency and accuracy of adaptive methods in the solution of field problems in computational medicine.

  9. Parallel paving: An algorithm for generating distributed, adaptive, all-quadrilateral meshes on parallel computers

    SciTech Connect (OSTI)

    Lober, R.R.; Tautges, T.J.; Vaughan, C.T.

    1997-03-01

    Paving is an automated mesh generation algorithm which produces all-quadrilateral elements. It can additionally generate these elements in varying sizes such that the resulting mesh adapts to a function distribution, such as an error function. While powerful, conventional paving is a very serial algorithm in its operation. Parallel paving is the extension of serial paving into parallel environments to perform the same meshing functions as conventional paving only on distributed, discretized models. This extension allows large, adaptive, parallel finite element simulations to take advantage of paving`s meshing capabilities for h-remap remeshing. A significantly modified version of the CUBIT mesh generation code has been developed to host the parallel paving algorithm and demonstrate its capabilities on both two dimensional and three dimensional surface geometries and compare the resulting parallel produced meshes to conventionally paved meshes for mesh quality and algorithm performance. Sandia`s {open_quotes}tiling{close_quotes} dynamic load balancing code has also been extended to work with the paving algorithm to retain parallel efficiency as subdomains undergo iterative mesh refinement.

  10. Modeling, mesh generation, and adaptive numerical methods for partial differential equations

    SciTech Connect (OSTI)

    Babuska, I.; Henshaw, W.D.; Oliger, J.E.; Flaherty, J.E.; Hopcroft, J.E.; Tezduyar, T.

    1995-12-31

    Mesh generation is one of the most time consuming aspects of computational solutions of problems involving partial differential equations. It is, furthermore, no longer acceptable to compute solutions without proper verification that specified accuracy criteria are being satisfied. Mesh generation must be related to the solution through computable estimates of discretization errors. Thus, an iterative process of alternate mesh and solution generation evolves in an adaptive manner with the end result that the solution is computed to prescribed specifications in an optimal, or at least efficient, manner. While mesh generation and adaptive strategies are becoming available, major computational challenges remain. One, in particular, involves moving boundaries and interfaces, such as free-surface flows and fluid-structure interactions. A 3-week program was held from July 5 to July 23, 1993 with 173 participants and 66 keynote, invited, and contributed presentations. This volume represents written versions of 21 of these lectures. These proceedings are organized roughly in order of their presentation at the workshop. Thus, the initial papers are concerned with geometry and mesh generation and discuss the representation of physical objects and surfaces on a computer and techniques to use this data to generate, principally, unstructured meshes of tetrahedral or hexahedral elements. The remainder of the papers cover adaptive strategies, error estimation, and applications. Several submissions deal with high-order p- and hp-refinement methods where mesh refinement/coarsening (h-refinement) is combined with local variation of method order (p-refinement). Combinations of mathematically verified and physically motivated approaches to error estimation are represented. Applications center on fluid mechanics. Selected papers are indexed separately for inclusion in the Energy Science and Technology Database.

  11. Automatic Mesh Adaptivity for Hybrid Monte Carlo/Deterministic Neutronics Modeling of Fusion Energy Systems

    SciTech Connect (OSTI)

    Ibrahim, Ahmad M; Wilson, P.; Sawan, M.; Mosher, Scott W; Peplow, Douglas E.; Grove, Robert E

    2013-01-01

    Three mesh adaptivity algorithms were developed to facilitate and expedite the use of the CADIS and FW-CADIS hybrid Monte Carlo/deterministic techniques in accurate full-scale neutronics simulations of fusion energy systems with immense sizes and complicated geometries. First, a macromaterial approach enhances the fidelity of the deterministic models without changing the mesh. Second, a deterministic mesh refinement algorithm generates meshes that capture as much geometric detail as possible without exceeding a specified maximum number of mesh elements. Finally, a weight window coarsening algorithm decouples the weight window mesh and energy bins from the mesh and energy group structure of the deterministic calculations in order to remove the memory constraint of the weight window map from the deterministic mesh resolution. The three algorithms were used to enhance an FW-CADIS calculation of the prompt dose rate throughout the ITER experimental facility and resulted in a 23.3% increase in the number of mesh tally elements in which the dose rates were calculated in a 10-day Monte Carlo calculation. Additionally, because of the significant increase in the efficiency of FW-CADIS simulations, the three algorithms enabled this difficult calculation to be accurately solved on a regular computer cluster, eliminating the need for a world-class super computer.

  12. High-Resolution Numerical Simulation and Analysis of Mach Reflection Structures in Detonation Waves in Low-Pressure H2O2Ar Mixtures: A Summary of Results Obtained with the Adaptive Mesh Refinement Framework AMROC

    DOE PAGES-Beta [OSTI]

    Deiterding, Ralf

    2011-01-01

    Numerical simulation can be key to the understanding of the multidimensional nature of transient detonation waves. However, the accurate approximation of realistic detonations is demanding as a wide range of scales needs to be resolved. This paper describes a successful solution strategy that utilizes logically rectangular dynamically adaptive meshes. The hydrodynamic transport scheme and the treatment of the nonequilibrium reaction terms are sketched. A ghost fluid approach is integrated into the method to allow for embedded geometrically complex boundaries. Large-scale parallel simulations of unstable detonation structures of Chapman-Jouguet detonations in low-pressure hydrogen-oxygen-argon mixtures demonstrate the efficiency of the described techniquesmorein practice. In particular, computations of regular cellular structures in two and three space dimensions and their development under transient conditions, that is, under diffraction and for propagation through bends are presented. Some of the observed patterns are classified by shock polar analysis, and a diagram of the transition boundaries between possible Mach reflection structures is constructed.less

  13. High-Resolution Numerical Simulation and Analysis of Mach Reflection Structures in Detonation Waves in Low-Pressure H 2 –O 2 –Ar Mixtures: A Summary of Results Obtained with the Adaptive Mesh Refinement Framework AMROC

    DOE PAGES-Beta [OSTI]

    Deiterding, Ralf

    2011-01-01

    Numerical simulation can be key to the understanding of the multidimensional nature of transient detonation waves. However, the accurate approximation of realistic detonations is demanding as a wide range of scales needs to be resolved. This paper describes a successful solution strategy that utilizes logically rectangular dynamically adaptive meshes. The hydrodynamic transport scheme and the treatment of the nonequilibrium reaction terms are sketched. A ghost fluid approach is integrated into the method to allow for embedded geometrically complex boundaries. Large-scale parallel simulations of unstable detonation structures of Chapman-Jouguet detonations in low-pressure hydrogen-oxygen-argon mixtures demonstrate the efficiency of the described techniquesmore » in practice. In particular, computations of regular cellular structures in two and three space dimensions and their development under transient conditions, that is, under diffraction and for propagation through bends are presented. Some of the observed patterns are classified by shock polar analysis, and a diagram of the transition boundaries between possible Mach reflection structures is constructed.« less

  14. Cosmos++: Relativistic Magnetohydrodynamics on Unstructured Grids with Local Adaptive Refinement

    SciTech Connect (OSTI)

    Anninos, P; Fragile, P C; Salmonson, J D

    2005-05-06

    A new code and methodology are introduced for solving the fully general relativistic magnetohydrodynamic (GRMHD) equations using time-explicit, finite-volume discretization. The code has options for solving the GRMHD equations using traditional artificial-viscosity (AV) or non-oscillatory central difference (NOCD) methods, or a new extended AV (eAV) scheme using artificial-viscosity together with a dual energy-flux-conserving formulation. The dual energy approach allows for accurate modeling of highly relativistic flows at boost factors well beyond what has been achieved to date by standard artificial viscosity methods. it provides the benefit of Godunov methods in capturing high Lorentz boosted flows but without complicated Riemann solvers, and the advantages of traditional artificial viscosity methods in their speed and flexibility. Additionally, the GRMHD equations are solved on an unstructured grid that supports local adaptive mesh refinement using a fully threated oct-tree (in three dimensions) network to traverse the grid hierarchy across levels and immediate neighbors. A number of tests are presented to demonstrate robustness of the numerical algorithms and adaptive mesh framework over a wide spectrum of problems, boosts, and astrophysical applications, including relativistic shock tubes, shock collisions, magnetosonic shocks, Alfven wave propagation, blast waves, magnetized Bondi flow, and the magneto-rotational instability in Kerr black hole spacetimes.

  15. Pillowing doublets: Refining a mesh to ensure that faces share at most one edge

    SciTech Connect (OSTI)

    Mitchell, S.A.; Tautges, T.J.

    1995-11-01

    Occasionally one may be confronted by a hexahedral or quadrilateral mesh containing doublets, two faces sharing two edges. In this case, no amount of smoothing will produce a mesh with agreeable element quality: in the planar case, one of these two faces will always have an angle of at least 180 degrees between the two edges. The authors describe a robust scheme for refining a hexahedral or quadrilateral mesh to separate such faces, so that any two faces share at most one edge. Note that this also ensures that two hexahedra share at most one face in the three dimensional case. The authors have implemented this algorithm and incorporated it into the CUBIT mesh generation environment developed at Sandia National Laboratories.

  16. Adaptive upscaling with the dual mesh method

    SciTech Connect (OSTI)

    Guerillot, D.; Verdiere, S.

    1997-08-01

    The objective of this paper is to demonstrate that upscaling should be calculated during the flow simulation instead of trying to enhance the a priori upscaling methods. Hence, counter-examples are given to motivate our approach, the so-called Dual Mesh Method. The main steps of this numerical algorithm are recalled. Applications illustrate the necessity to consider different average relative permeability values depending on the direction in space. Moreover, these values could be different for the same average saturation. This proves that an a priori upscaling cannot be the answer even in homogeneous cases because of the {open_quotes}dynamical heterogeneity{close_quotes} created by the saturation profile. Other examples show the efficiency of the Dual Mesh Method applied to heterogeneous medium and to an actual field case in South America.

  17. Dimensional reduction as a tool for mesh refinement and trackingsingularities of PDEs

    SciTech Connect (OSTI)

    Stinis, Panagiotis

    2007-06-10

    We present a collection of algorithms which utilizedimensional reduction to perform mesh refinement and study possiblysingular solutions of time-dependent partial differential equations. Thealgorithms are inspired by constructions used in statistical mechanics toevaluate the properties of a system near a critical point. The firstalgorithm allows the accurate determination of the time of occurrence ofa possible singularity. The second algorithm is an adaptive meshrefinement scheme which can be used to approach efficiently the possiblesingularity. Finally, the third algorithm uses the second algorithm untilthe available resolution is exhausted (as we approach the possiblesingularity) and then switches to a dimensionally reduced model which,when accurate, can follow faithfully the solution beyond the time ofoccurrence of the purported singularity. An accurate dimensionallyreduced model should dissipate energy at the right rate. We construct twovariants of each algorithm. The first variant assumes that we have actualknowledge of the reduced model. The second variant assumes that we knowthe form of the reduced model, i.e., the terms appearing in the reducedmodel, but not necessarily their coefficients. In this case, we alsoprovide a way of determining the coefficients. We present numericalresults for the Burgers equation with zero and nonzero viscosity toillustrate the use of the algorithms.

  18. The parallelization of an advancing-front, all-quadrilateral meshing algorithm for adaptive analysis

    SciTech Connect (OSTI)

    Lober, R.R.; Tautges, T.J.; Cairncross, R.A.

    1995-11-01

    The ability to perform effective adaptive analysis has become a critical issue in the area of physical simulation. Of the multiple technologies required to realize a parallel adaptive analysis capability, automatic mesh generation is an enabling technology, filling a critical need in the appropriate discretization of a problem domain. The paving algorithm`s unique ability to generate a function-following quadrilateral grid is a substantial advantage in Sandia`s pursuit of a modified h-method adaptive capability. This characteristic combined with a strong transitioning ability allow the paving algorithm to place elements where an error function indicates more mesh resolution is needed. Although the original paving algorithm is highly serial, a two stage approach has been designed to parallelize the algorithm but also retain the nice qualities of the serial algorithm. The authors approach also allows the subdomain decomposition used by the meshing code to be shared with the finite element physics code, eliminating the need for data transfer across the processors between the analysis and remeshing steps. In addition, the meshed subdomains are adjusted with a dynamic load balancer to improve the original decomposition and maintain load efficiency each time the mesh has been regenerated. This initial parallel implementation assumes an approach of restarting the physics problem from time zero at each interaction, with a refined mesh adapting to the previous iterations objective function. The remeshing tools are being developed to enable real time remeshing and geometry regeneration. Progress on the redesign of the paving algorithm for parallel operation is discussed including extensions allowing adaptive control and geometry regeneration.

  19. Automatic mesh adaptivity for hybrid Monte Carlo/deterministic neutronics modeling of difficult shielding problems

    SciTech Connect (OSTI)

    Ibrahim, Ahmad M.; Wilson, Paul P.H.; Sawan, Mohamed E.; Mosher, Scott W.; Peplow, Douglas E.; Wagner, John C.; Evans, Thomas M.; Grove, Robert E.

    2015-06-30

    The CADIS and FW-CADIS hybrid Monte Carlo/deterministic techniques dramatically increase the efficiency of neutronics modeling, but their use in the accurate design analysis of very large and geometrically complex nuclear systems has been limited by the large number of processors and memory requirements for their preliminary deterministic calculations and final Monte Carlo calculation. Three mesh adaptivity algorithms were developed to reduce the memory requirements of CADIS and FW-CADIS without sacrificing their efficiency improvement. First, a macromaterial approach enhances the fidelity of the deterministic models without changing the mesh. Second, a deterministic mesh refinement algorithm generates meshes that capture as much geometric detail as possible without exceeding a specified maximum number of mesh elements. Finally, a weight window coarsening algorithm decouples the weight window mesh and energy bins from the mesh and energy group structure of the deterministic calculations in order to remove the memory constraint of the weight window map from the deterministic mesh resolution. The three algorithms were used to enhance an FW-CADIS calculation of the prompt dose rate throughout the ITER experimental facility. Using these algorithms resulted in a 23.3% increase in the number of mesh tally elements in which the dose rates were calculated in a 10-day Monte Carlo calculation and, additionally, increased the efficiency of the Monte Carlo simulation by a factor of at least 3.4. The three algorithms enabled this difficult calculation to be accurately solved using an FW-CADIS simulation on a regular computer cluster, eliminating the need for a world-class super computer.

  20. Automatic mesh adaptivity for hybrid Monte Carlo/deterministic neutronics modeling of difficult shielding problems

    DOE PAGES-Beta [OSTI]

    Ibrahim, Ahmad M.; Wilson, Paul P.H.; Sawan, Mohamed E.; Mosher, Scott W.; Peplow, Douglas E.; Wagner, John C.; Evans, Thomas M.; Grove, Robert E.

    2015-06-30

    The CADIS and FW-CADIS hybrid Monte Carlo/deterministic techniques dramatically increase the efficiency of neutronics modeling, but their use in the accurate design analysis of very large and geometrically complex nuclear systems has been limited by the large number of processors and memory requirements for their preliminary deterministic calculations and final Monte Carlo calculation. Three mesh adaptivity algorithms were developed to reduce the memory requirements of CADIS and FW-CADIS without sacrificing their efficiency improvement. First, a macromaterial approach enhances the fidelity of the deterministic models without changing the mesh. Second, a deterministic mesh refinement algorithm generates meshes that capture as muchmore » geometric detail as possible without exceeding a specified maximum number of mesh elements. Finally, a weight window coarsening algorithm decouples the weight window mesh and energy bins from the mesh and energy group structure of the deterministic calculations in order to remove the memory constraint of the weight window map from the deterministic mesh resolution. The three algorithms were used to enhance an FW-CADIS calculation of the prompt dose rate throughout the ITER experimental facility. Using these algorithms resulted in a 23.3% increase in the number of mesh tally elements in which the dose rates were calculated in a 10-day Monte Carlo calculation and, additionally, increased the efficiency of the Monte Carlo simulation by a factor of at least 3.4. The three algorithms enabled this difficult calculation to be accurately solved using an FW-CADIS simulation on a regular computer cluster, eliminating the need for a world-class super computer.« less

  1. Automatic mesh adaptivity for CADIS and FW-CADIS neutronics modeling of difficult shielding problems

    SciTech Connect (OSTI)

    Ibrahim, A. M.; Peplow, D. E.; Mosher, S. W.; Wagner, J. C.; Evans, T. M.; Wilson, P. P.; Sawan, M. E.

    2013-07-01

    The CADIS and FW-CADIS hybrid Monte Carlo/deterministic techniques dramatically increase the efficiency of neutronics modeling, but their use in the accurate design analysis of very large and geometrically complex nuclear systems has been limited by the large number of processors and memory requirements for their preliminary deterministic calculations and final Monte Carlo calculation. Three mesh adaptivity algorithms were developed to reduce the memory requirements of CADIS and FW-CADIS without sacrificing their efficiency improvement. First, a macro-material approach enhances the fidelity of the deterministic models without changing the mesh. Second, a deterministic mesh refinement algorithm generates meshes that capture as much geometric detail as possible without exceeding a specified maximum number of mesh elements. Finally, a weight window coarsening algorithm de-couples the weight window mesh and energy bins from the mesh and energy group structure of the deterministic calculations in order to remove the memory constraint of the weight window map from the deterministic mesh resolution. The three algorithms were used to enhance an FW-CADIS calculation of the prompt dose rate throughout the ITER experimental facility. Using these algorithms resulted in a 23.3% increase in the number of mesh tally elements in which the dose rates were calculated in a 10-day Monte Carlo calculation and, additionally, increased the efficiency of the Monte Carlo simulation by a factor of at least 3.4. The three algorithms enabled this difficult calculation to be accurately solved using an FW-CADIS simulation on a regular computer cluster, obviating the need for a world-class super computer. (authors)

  2. Local timespace mesh refinement for simulation of elastic wave propagation in multi-scale media

    SciTech Connect (OSTI)

    Kostin, Victor; Lisitsa, Vadim; Reshetova, Galina; Tcheverda, Vladimir

    2015-01-15

    This paper presents an original approach to local timespace grid refinement for the numerical simulation of wave propagation in models with localized clusters of micro-heterogeneities. The main features of the algorithm are the application of temporal and spatial refinement on two different surfaces; the use of the embedded-stencil technique for the refinement of grid step with respect to time; the use of the Fast Fourier Transform (FFT)-based interpolation to couple variables for spatial mesh refinement. The latter makes it possible to perform filtration of high spatial frequencies, which provides stability in the proposed finite-difference schemes. In the present work, the technique is implemented for the finite-difference simulation of seismic wave propagation and the interaction of such waves with fluid-filled fractures and cavities of carbonate reservoirs. However, this approach is easy to adapt and/or combine with other numerical techniques, such as finite elements, discontinuous Galerkin method, or finite volumes used for approximation of various types of linear and nonlinear hyperbolic equations.

  3. Simulating the quartic Galileon gravity model on adaptively refined meshes

    SciTech Connect (OSTI)

    Li, Baojiu; Barreira, Alexandre; Baugh, Carlton M.; Hellwing, Wojciech A.; Koyama, Kazuya; Zhao, Gong-Bo; Pascoli, Silvia E-mail: baojiu.li@durham.ac.uk E-mail: wojciech.hellwing@durham.ac.uk E-mail: silvia.pascoli@durham.ac.uk

    2013-11-01

    We develop a numerical algorithm to solve the high-order nonlinear derivative-coupling equation associated with the quartic Galileon model, and implement it in a modified version of the ramses N-body code to study the effect of the Galileon field on the large-scale matter clustering. The algorithm is tested for several matter field configurations with different symmetries, and works very well. This enables us to perform the first simulations for a quartic Galileon model which provides a good fit to the cosmic microwave background (CMB) anisotropy, supernovae and baryonic acoustic oscillations (BAO) data. Our result shows that the Vainshtein mechanism in this model is very efficient in suppressing the spatial variations of the scalar field. However, the time variation of the effective Newtonian constant caused by the curvature coupling of the Galileon field cannot be suppressed by the Vainshtein mechanism. This leads to a significant weakening of the strength of gravity in high-density regions at late times, and therefore a weaker matter clustering on small scales. We also find that without the Vainshtein mechanism the model would have behaved in a completely different way, which shows the crucial role played by nonlinearities in modified gravity theories and the importance of performing self-consistent N-body simulations for these theories.

  4. Enzo: An Adaptive Mesh Refinement Code for Astrophysics (Journal...

    Office of Scientific and Technical Information (OSTI)

    J. ; Reynolds, Daniel R. ; Collins, David C. ; Wang, Peng ; Skillman, Samuel W. ; Smith, Britton ; Harkness, Robert P. ; Bordner, James ; Kim, Ji-hoon ; Kuhlen, Michael ; Xu, ...

  5. ENZO: AN ADAPTIVE MESH REFINEMENT CODE FOR ASTROPHYSICS (Journal...

    Office of Scientific and Technical Information (OSTI)

    Authors: Bryan, Greg L. ; Turk, Matthew J. 1 ; Norman, Michael L. ; Bordner, James ; Xu, Hao ; Kritsuk, Alexei G. 2 ; O'Shea, Brian W. ; Smith, Britton 3 ; Abel, Tom ; Wang, ...

  6. A Predictive Model of Fragmentation using Adaptive Mesh Refinement...

    U.S. Department of Energy (DOE) all webpages (Extended Search)

    A new arena for predictive simulations in high- powered laser systems "12 NIF" Or 96 ... Numerical simulations show how to mitigate damage from debris and shrapnel Damage prior to ...

  7. Adaptive h -refinement for reduced-order models: ADAPTIVE h -refinement for reduced-order models

    SciTech Connect (OSTI)

    Carlberg, Kevin T.

    2014-11-05

    Our work presents a method to adaptively refine reduced-order models a posteriori without requiring additional full-order-model solves. The technique is analogous to mesh-adaptive h-refinement: it enriches the reduced-basis space online by ‘splitting’ a given basis vector into several vectors with disjoint support. The splitting scheme is defined by a tree structure constructed offline via recursive k-means clustering of the state variables using snapshot data. This method identifies the vectors to split online using a dual-weighted-residual approach that aims to reduce error in an output quantity of interest. The resulting method generates a hierarchy of subspaces online without requiring large-scale operations or full-order-model solves. Furthermore, it enables the reduced-order model to satisfy any prescribed error tolerance regardless of its original fidelity, as a completely refined reduced-order model is mathematically equivalent to the original full-order model. Experiments on a parameterized inviscid Burgers equation highlight the ability of the method to capture phenomena (e.g., moving shocks) not contained in the span of the original reduced basis.

  8. The Effective Combination of Mesh Adaptation and Non-linearThermo...

    Office of Scientific and Technical Information (OSTI)

    The Effective Combination of Mesh Adaptation and Non-linear Thermo-mechanical Solution Components for the Modeling of Weld Failures. Citation Details In-Document Search Title: The...

  9. The design of a parallel adaptive paving all-quadrilateral meshing algorithm

    SciTech Connect (OSTI)

    Tautges, T.J.; Lober, R.R.; Vaughan, C.

    1995-08-01

    Adaptive finite element analysis demands a great deal of computational resources, and as such is most appropriately solved in a massively parallel computer environment. This analysis will require other parallel algorithms before it can fully utilize MP computers, one of which is parallel adaptive meshing. A version of the paving algorithm is being designed which operates in parallel but which also retains the robustness and other desirable features present in the serial algorithm. Adaptive paving in a production mode is demonstrated using a Babuska-Rheinboldt error estimator on a classic linearly elastic plate problem. The design of the parallel paving algorithm is described, and is based on the decomposition of a surface into {open_quotes}virtual{close_quotes} surfaces. The topology of the virtual surface boundaries is defined using mesh entities (mesh nodes and edges) so as to allow movement of these boundaries with smoothing and other operations. This arrangement allows the use of the standard paving algorithm on subdomain interiors, after the negotiation of the boundary mesh.

  10. Solving kinetic equations with adaptive mesh in phase space for rarefied gas dynamics and plasma physics (Invited)

    SciTech Connect (OSTI)

    Kolobov, Vladimir; Arslanbekov, Robert; Frolova, Anna

    2014-12-09

    The paper describes an Adaptive Mesh in Phase Space (AMPS) technique for solving kinetic equations with deterministic mesh-based methods. The AMPS technique allows automatic generation of adaptive Cartesian mesh in both physical and velocity spaces using a Tree-of-Trees data structure. We illustrate advantages of AMPS for simulations of rarefied gas dynamics and electron kinetics on low temperature plasmas. In particular, we consider formation of the velocity distribution functions in hypersonic flows, particle kinetics near oscillating boundaries, and electron kinetics in a radio-frequency sheath. AMPS provide substantial savings in computational cost and increased efficiency of the mesh-based kinetic solvers.

  11. Minimising the error in eigenvalue calculations involving the Boltzmann transport equation using goal-based adaptivity on unstructured meshes

    SciTech Connect (OSTI)

    Goffin, Mark A.; Baker, Christopher M.J.; Buchan, Andrew G.; Pain, Christopher C.; Eaton, Matthew D.; Smith, Paul N.

    2013-06-01

    This article presents a method for goal-based anisotropic adaptive methods for the finite element method applied to the Boltzmann transport equation. The neutron multiplication factor, k{sub eff}, is used as the goal of the adaptive procedure. The anisotropic adaptive algorithm requires error measures for k{sub eff} with directional dependence. General error estimators are derived for any given functional of the flux and applied to k{sub eff} to acquire the driving force for the adaptive procedure. The error estimators require the solution of an appropriately formed dual equation. Forward and dual error indicators are calculated by weighting the Hessian of each solution with the dual and forward residual respectively. The Hessian is used as an approximation of the interpolation error in the solution which gives rise to the directional dependence. The two indicators are combined to form a single error metric that is used to adapt the finite element mesh. The residual is approximated using a novel technique arising from the sub-grid scale finite element discretisation. Two adaptive routes are demonstrated: (i) a single mesh is used to solve all energy groups, and (ii) a different mesh is used to solve each energy group. The second method aims to capture the benefit from representing the flux from each energy group on a specifically optimised mesh. The k{sub eff} goal-based adaptive method was applied to three examples which illustrate the superior accuracy in criticality problems that can be obtained.

  12. An adaptive grid refinement strategy for the simulation of negative streamers

    SciTech Connect (OSTI)

    Montijn, C. . E-mail: carolynne.montijn@cwi.nl; Hundsdorfer, W. . E-mail: willem.hundsdorfer@cwi.nl; Ebert, U. . E-mail: ute.ebert@cwi.nl

    2006-12-10

    The evolution of negative streamers during electric breakdown of a non-attaching gas can be described by a two-fluid model for electrons and positive ions. It consists of continuity equations for the charged particles including drift, diffusion and reaction in the local electric field, coupled to the Poisson equation for the electric potential. The model generates field enhancement and steep propagating ionization fronts at the tip of growing ionized filaments. An adaptive grid refinement method for the simulation of these structures is presented. It uses finite volume spatial discretizations and explicit time stepping, which allows the decoupling of the grids for the continuity equations from those for the Poisson equation. Standard refinement methods in which the refinement criterion is based on local error monitors fail due to the pulled character of the streamer front that propagates into a linearly unstable state. We present a refinement method which deals with all these features. Tests on one-dimensional streamer fronts as well as on three-dimensional streamers with cylindrical symmetry (hence effectively 2D for numerical purposes) are carried out successfully. Results on fine grids are presented, they show that such an adaptive grid method is needed to capture the streamer characteristics well. This refinement strategy enables us to adequately compute negative streamers in pure gases in the parameter regime where a physical instability appears: branching streamers.

  13. 6th International Meshing Roundtable '97

    SciTech Connect (OSTI)

    White, D.

    1997-09-01

    The goal of the 6th International Meshing Roundtable is to bring together researchers and developers from industry, academia, and government labs in a stimulating, open environment for the exchange of technical information related to the meshing process. In the pas~ the Roundtable has enjoyed significant participation born each of these groups from a wide variety of countries. The Roundtable will consist of technical presentations from contributed papers and abstracts, two invited speakers, and two invited panels of experts discussing topics related to the development and use of automatic mesh generation tools. In addition, this year we will feature a "Bring Your Best Mesh" competition and poster session to encourage discussion and participation from a wide variety of mesh generation tool users. The schedule and evening social events are designed to provide numerous opportunities for informal dialog. A proceedings will be published by Sandia National Laboratories and distributed at the Roundtable. In addition, papers of exceptionally high quaIity will be submitted to a special issue of the International Journal of Computational Geometry and Applications. Papers and one page abstracts were sought that present original results on the meshing process. Potential topics include but are got limited to: Unstructured triangular and tetrahedral mesh generation Unstructured quadrilateral and hexahedral mesh generation Automated blocking and structured mesh generation Mixed element meshing Surface mesh generation Geometry decomposition and clean-up techniques Geometry modification techniques related to meshing Adaptive mesh refinement and mesh quality control Mesh visualization Special purpose meshing algorithms for particular applications Theoretical or novel ideas with practical potential Technical presentations from industrial researchers.

  14. COLLABORATIVE RESEARCH: CONTINUOUS DYNAMIC GRID ADAPTATION IN A GLOBAL ATMOSPHERIC MODEL: APPLICATION AND REFINEMENT

    SciTech Connect (OSTI)

    Gutowski, William J.; Prusa, Joseph M.; Smolarkiewicz, Piotr K.

    2012-05-08

    This project had goals of advancing the performance capabilities of the numerical general circulation model EULAG and using it to produce a fully operational atmospheric global climate model (AGCM) that can employ either static or dynamic grid stretching for targeted phenomena. The resulting AGCM combined EULAG's advanced dynamics core with the "physics" of the NCAR Community Atmospheric Model (CAM). Effort discussed below shows how we improved model performance and tested both EULAG and the coupled CAM-EULAG in several ways to demonstrate the grid stretching and ability to simulate very well a wide range of scales, that is, multi-scale capability. We leveraged our effort through interaction with an international EULAG community that has collectively developed new features and applications of EULAG, which we exploited for our own work summarized here. Overall, the work contributed to over 40 peer-reviewed publications and over 70 conference/workshop/seminar presentations, many of them invited. 3a. EULAG Advances EULAG is a non-hydrostatic, parallel computational model for all-scale geophysical flows. EULAG's name derives from its two computational options: EULerian (flux form) or semi-LAGrangian (advective form). The model combines nonoscillatory forward-in-time (NFT) numerical algorithms with a robust elliptic Krylov solver. A signature feature of EULAG is that it is formulated in generalized time-dependent curvilinear coordinates. In particular, this enables grid adaptivity. In total, these features give EULAG novel advantages over many existing dynamical cores. For EULAG itself, numerical advances included refining boundary conditions and filters for optimizing model performance in polar regions. We also added flexibility to the model's underlying formulation, allowing it to work with the pseudo-compressible equation set of Durran in addition to EULAG's standard anelastic formulation. Work in collaboration with others also extended the demonstrated range of

  15. Interpolation Methods and the Accuracy of Lattice-Boltzmann Mesh...

    Office of Scientific and Technical Information (OSTI)

    of Lattice-Boltzmann Mesh Refinement Citation Details In-Document Search Title: Interpolation Methods and the Accuracy of Lattice-Boltzmann Mesh Refinement You are ...

  16. Development of Adaptive Model Refinement (AMoR) for Multiphysics and Multifidelity Problems

    SciTech Connect (OSTI)

    Turinsky, Paul

    2015-02-09

    This project investigated the development and utilization of Adaptive Model Refinement (AMoR) for nuclear systems simulation applications. AMoR refers to utilization of several models of physical phenomena which differ in prediction fidelity. If the highest fidelity model is judged to always provide or exceeded the desired fidelity, than if one can determine the difference in a Quantity of Interest (QoI) between the highest fidelity model and lower fidelity models, one could utilize the fidelity model that would just provide the magnitude of the QoI desired. Assuming lower fidelity models require less computational resources, in this manner computational efficiency can be realized provided the QoI value can be accurately and efficiently evaluated. This work utilized Generalized Perturbation Theory (GPT) to evaluate the QoI, by convoluting the GPT solution with the residual of the highest fidelity model determined using the solution from lower fidelity models. Specifically, a reactor core neutronics problem and thermal-hydraulics problem were studied to develop and utilize AMoR. The highest fidelity neutronics model was based upon the 3D space-time, two-group, nodal diffusion equations as solved in the NESTLE computer code. Added to the NESTLE code was the ability to determine the time-dependent GPT neutron flux. The lower fidelity neutronics model was based upon the point kinetics equations along with utilization of a prolongation operator to determine the 3D space-time, two-group flux. The highest fidelity thermal-hydraulics model was based upon the space-time equations governing fluid flow in a closed channel around a heat generating fuel rod. The Homogenous Equilibrium Mixture (HEM) model was used for the fluid and Finite Difference Method was applied to both the coolant and fuel pin energy conservation equations. The lower fidelity thermal-hydraulic model was based upon the same equations as used for the highest fidelity model but now with coarse spatial

  17. Enhancing adaptive sparse grid approximations and improving refinement strategies using adjoint-based a posteriori error estimates

    DOE PAGES-Beta [OSTI]

    Jakeman, J. D.; Wildey, T.

    2015-01-01

    In this paper we present an algorithm for adaptive sparse grid approximations of quantities of interest computed from discretized partial differential equations. We use adjoint-based a posteriori error estimates of the interpolation error in the sparse grid to enhance the sparse grid approximation and to drive adaptivity. We show that utilizing these error estimates provides significantly more accurate functional values for random samples of the sparse grid approximation. We also demonstrate that alternative refinement strategies based upon a posteriori error estimates can lead to further increases in accuracy in the approximation over traditional hierarchical surplus based strategies. Throughout this papermore » we also provide and test a framework for balancing the physical discretization error with the stochastic interpolation error of the enhanced sparse grid approximation.« less

  18. Enhancing adaptive sparse grid approximations and improving refinement strategies using adjoint-based a posteriori error estimates

    SciTech Connect (OSTI)

    Jakeman, J.D. Wildey, T.

    2015-01-01

    In this paper we present an algorithm for adaptive sparse grid approximations of quantities of interest computed from discretized partial differential equations. We use adjoint-based a posteriori error estimates of the physical discretization error and the interpolation error in the sparse grid to enhance the sparse grid approximation and to drive adaptivity of the sparse grid. Utilizing these error estimates provides significantly more accurate functional values for random samples of the sparse grid approximation. We also demonstrate that alternative refinement strategies based upon a posteriori error estimates can lead to further increases in accuracy in the approximation over traditional hierarchical surplus based strategies. Throughout this paper we also provide and test a framework for balancing the physical discretization error with the stochastic interpolation error of the enhanced sparse grid approximation.

  19. Final Report for Collaborative Project: Sensitivity of Atmospheric Parametric Formulations to Regional Mesh Refinement in Global Climate Simulations Using CESM-HOMME

    SciTech Connect (OSTI)

    Neale, Richard B.

    2015-12-01

    In this project we analyze climate simulations using the Community Earth System Model (CESM) in order to determine the modeled response and sensitivity to horizontal resolution. Simple aqua-planet configurations were used to provide a clean comparison of the response to resolution in CESM. This enables us to easily examine all aspects of the model sensitivity to resolution including mean quantities, variability and physical parameterization tendencies: the chief reflection of resolution sensitivity. An extension to the global resolution sensitivity study is the examination of regional grid refinement where resolution changes are prescribed in a single global simulation. We examine the relevance of the global resolution sensitivity results as applied to these regional refinement simulations. In particular we examine how variations in the grid resolution, centered on different parts of the globe, lead to differences in the parameterized response and the potential to generate residual circulations as a result. Given the potential to generate this resolution sensitivity we examine simple modifications to the parameterized physics that are able to moderate any residual circulations. Finally, we transfer the framework to the standard AMIP configuration to examine the resolution sensitivity in the presence of compounding effects such as land-sea distributions, orography and seasonal variation.

  20. A mesh-adaptive collocation technique for the simulation of advection-dominated single- and multiphase transport phenomena in porous media

    SciTech Connect (OSTI)

    Koch, M.

    1995-12-31

    A new mesh-adaptive 1D collocation technique has been developed to efficiently solve transient advection-dominated transport problems in porous media that are governed by a hyperbolic/parabolic (singularly perturbed) PDE. After spatial discretization a singularly perturbed ODE is obtained which is solved by a modification of the COLNEW ODE-collocation code. The latter also contains an adaptive mesh procedure that has been enhanced here to resolve linear and nonlinear transport flow problems with steep fronts where regular FD and FE methods often fail. An implicit first-order backward Euler and a third-order Taylor-Donea technique are employed for the time integration. Numerical simulations on a variety of high Peclet-number transport phenomena as they occur in realistic porous media flow situations are presented. Examples include classical linear advection-diffusion, nonlinear adsorption, two-phase Buckley-Leverett flow without and with capillary forces (Rapoport-Leas equation) and Burgers` equation for inviscid fluid flow. In most of these examples sharp fronts and/or shocks develop which are resolved in an oscillation-free manner by the present adaptive collocation method. The backward Euler method has some amount of numerical dissipation is observed when the time-steps are too large. The third-order Taylor-Donea technique is less dissipative but is more prone to numerical oscillations. The simulations show that for the efficient solution of nonlinear singularly perturbed PDE`s governing flow transport a careful balance must be struck between the optimal mesh adaptation, the nonlinear iteration method and the time-stepping procedure. More theoretical research is needed with this regard.

  1. An adaptive multiblock high-order finite-volume method for solving the shallow-water equations on the sphere

    SciTech Connect (OSTI)

    McCorquodale, Peter; Ullrich, Paul; Johansen, Hans; Colella, Phillip

    2015-09-04

    We present a high-order finite-volume approach for solving the shallow-water equations on the sphere, using multiblock grids on the cubed-sphere. This approach combines a Runge--Kutta time discretization with a fourth-order accurate spatial discretization, and includes adaptive mesh refinement and refinement in time. Results of tests show fourth-order convergence for the shallow-water equations as well as for advection in a highly deformational flow. Hierarchical adaptive mesh refinement allows solution error to be achieved that is comparable to that obtained with uniform resolution of the most refined level of the hierarchy, but with many fewer operations.

  2. Method of modifying a volume mesh using sheet insertion

    DOE Patents [OSTI]

    Borden, Michael J.; Shepherd, Jason F.

    2006-08-29

    A method and machine-readable medium provide a technique to modify a hexahedral finite element volume mesh using dual generation and sheet insertion. After generating a dual of a volume stack (mesh), a predetermined algorithm may be followed to modify (refine) the volume mesh of hexahedral elements. The predetermined algorithm may include the steps of locating a sheet of hexahedral mesh elements, determining a plurality of hexahedral elements within the sheet to refine, shrinking the plurality of elements, and inserting a new sheet of hexahedral elements adjacently to modify the volume mesh. Additionally, another predetermined algorithm using mesh cutting may be followed to modify a volume mesh.

  3. Generation of multi-million element meshes for solid model-based geometries: The Dicer algorithm

    SciTech Connect (OSTI)

    Melander, D.J.; Benzley, S.E.; Tautges, T.J.

    1997-06-01

    The Dicer algorithm generates a fine mesh by refining each element in a coarse all-hexahedral mesh generated by any existing all-hexahedral mesh generation algorithm. The fine mesh is geometry-conforming. Using existing all-hexahedral meshing algorithms to define the initial coarse mesh simplifies the overall meshing process and allows dicing to take advantage of improvements in other meshing algorithms immediately. The Dicer algorithm will be used to generate large meshes in support of the ASCI program. The authors also plan to use dicing as the basis for parallel mesh generation. Dicing strikes a careful balance between the interactive mesh generation and multi-million element mesh generation processes for complex 3D geometries, providing an efficient means for producing meshes of varying refinement once the coarse mesh is obtained.

  4. MeshKit

    Energy Science and Technology Software Center (OSTI)

    2010-10-05

    MeshKit is an open-source library of mesh generation functionality. MeshKit has general mesh manipulation and generation functions such as Copoy, Move, Rotate and Extrude mesh. In addition, new quad mesh and embedded boundary Cartesian mesh algorithm (EB Mesh) are included. Interfaces to several public domain meshing algorithms (TetGen, netgen, triangle, Gmsh, camal) are also offered. This library interacts with mesh data mostly through iMesh including accessing the mesh in parallel. It also can interact withmore » iGeom interface to provide geometry functionality such as importing solid model based geometries. iGeom and IMesh are implemented in the CGM and MOAB packages, respectively. For some non-existing function in iMesh such as tree-construction and ray-tracing, MeshKit also interacts with MOAB functions directly.« less

  5. Quadrilateral/hexahedral finite element mesh coarsening

    DOE Patents [OSTI]

    Staten, Matthew L; Dewey, Mark W; Scott, Michael A; Benzley, Steven E

    2012-10-16

    A technique for coarsening a finite element mesh ("FEM") is described. This technique includes identifying a coarsening region within the FEM to be coarsened. Perimeter chords running along perimeter boundaries of the coarsening region are identified. The perimeter chords are redirected to create an adaptive chord separating the coarsening region from a remainder of the FEM. The adaptive chord runs through mesh elements residing along the perimeter boundaries of the coarsening region. The adaptive chord is then extracted to coarsen the FEM.

  6. Solution-verified reliability analysis and design of bistable MEMS using error estimation and adaptivity.

    SciTech Connect (OSTI)

    Eldred, Michael Scott; Subia, Samuel Ramirez; Neckels, David; Hopkins, Matthew Morgan; Notz, Patrick K.; Adams, Brian M.; Carnes, Brian; Wittwer, Jonathan W.; Bichon, Barron J.; Copps, Kevin D.

    2006-10-01

    This report documents the results for an FY06 ASC Algorithms Level 2 milestone combining error estimation and adaptivity, uncertainty quantification, and probabilistic design capabilities applied to the analysis and design of bistable MEMS. Through the use of error estimation and adaptive mesh refinement, solution verification can be performed in an automated and parameter-adaptive manner. The resulting uncertainty analysis and probabilistic design studies are shown to be more accurate, efficient, reliable, and convenient.

  7. Mesh Morphing Pier Analysis

    U.S. Department of Energy (DOE) all webpages (Extended Search)

    Application of Mesh Morphing in STAR-CCM+ to Analysis of Scour at Cylindrical Piers Mesh morphing is a fluid structure interaction capability in STAR-CCM+ to move vertices in the computational mesh in a way that preserves mesh quality when a boundary moves. The equations being solved include terms that account for the motion of the mesh maintaining mass and property balances during the solution process. Initial work on leveraging the mesh morphing FSI capability for efficient application to

  8. MHD simulations on an unstructured mesh

    SciTech Connect (OSTI)

    Strauss, H.R.; Park, W.; Belova, E.; Fu, G.Y.; Longcope, D.W.; Sugiyama, L.E.

    1998-12-31

    Two reasons for using an unstructured computational mesh are adaptivity, and alignment with arbitrarily shaped boundaries. Two codes which use finite element discretization on an unstructured mesh are described. FEM3D solves 2D and 3D RMHD using an adaptive grid. MH3D++, which incorporates methods of FEM3D into the MH3D generalized MHD code, can be used with shaped boundaries, which might be 3D.

  9. Rietveld Refinement

    U.S. Department of Energy (DOE) all webpages (Extended Search)

    profile Chi-squared value 4.944 Progress so far Inverse Modeling Method 2 Fourier Method Data Model Refined Structure 40 60 80 100 120 140 160 0 1000 2000 3000 4000...

  10. A node-centered local refinement algorithm for poisson's equation in complex geometries

    SciTech Connect (OSTI)

    McCorquodale, Peter; Colella, Phillip; Grote, David P.; Vay, Jean-Luc

    2004-05-04

    This paper presents a method for solving Poisson's equation with Dirichlet boundary conditions on an irregular bounded three-dimensional region. The method uses a nodal-point discretization and adaptive mesh refinement (AMR) on Cartesian grids, and the AMR multigrid solver of Almgren. The discrete Laplacian operator at internal boundaries comes from either linear or quadratic (Shortley-Weller) extrapolation, and the two methods are compared. It is shown that either way, solution error is second order in the mesh spacing. Error in the gradient of the solution is first order with linear extrapolation, but second order with Shortley-Weller. Examples are given with comparison with the exact solution. The method is also applied to a heavy-ion fusion accelerator problem, showing the advantage of adaptivity.

  11. Midcourse Refinements of Financing Strategies

    Energy.gov [DOE]

    Better Buildings Neighborhood Program Financing Peer Exchange Call: Midcourse Refinements of Financing Strategies, Call Slides and Discussion Summary, March 29, 2012. During this webinar participants discussed how programs have adapted and refined their financing strategies based on initial implementation experience and learning.

  12. Mesh Quality Improvement Toolkit

    Energy Science and Technology Software Center (OSTI)

    2002-11-15

    MESQUITE is a linkable software library to be used by simulation and mesh generation tools to improve the quality of meshes. Mesh quality is improved by node movement and/or local topological modifications. Various aspects of mesh quality such as smoothness, element shape, size, and orientation are controlled by choosing the appropriate mesh qualtiy metric, and objective function tempate, and a numerical optimization solver to optimize the quality of meshes, MESQUITE uses the TSTT mesh interfacemore » specification to provide an interoperable toolkit that can be used by applications which adopt the standard. A flexible code design makes it easy for meshing researchers to add additional mesh quality metrics, templates, and solvers to develop new quality improvement algorithms by making use of the MESQUITE infrastructure.« less

  13. Adaptive methods and parallel computation for partial differential equations. Final report

    SciTech Connect (OSTI)

    Biswas, R.; Benantar, M.; Flaherty, J.E.

    1992-05-01

    Consider the adaptive solution of two-dimensional vector systems of hyperbolic and elliptic partial differential equations on shared-memory parallel computers. Hyperbolic systems are approximated by an explicit finite volume technique and solved by a recursive local mesh refinement procedure on a tree-structured grid. Local refinement of the time steps and spatial cells of a coarse base mesh is performed in regions where a refinement indicator exceeds a prescribed tolerance. Computational procedures that sequentially traverse the tree while processing solutions on each grid in parallel, that process solutions at the same tree level in parallel, and that dynamically assign processors to nodes of the tree have been developed and applied to an example. Computational results comparing a variety of heuristic processor load balancing techniques and refinement strategies are presented.

  14. AZEuS: AN ADAPTIVE ZONE EULERIAN SCHEME FOR COMPUTATIONAL MAGNETOHYDRODYNAMICS

    SciTech Connect (OSTI)

    Ramsey, Jon P.; Clarke, David A. [Institute for Computational Astrophysics, Department of Astronomy and Physics, Saint Mary's University, Halifax, Nova Scotia B3H 3C3 (Canada); Men'shchikov, Alexander B. [Laboratoire AIM, CEA/DSM-CNRS-Universite Paris Diderot, IRFU/SAp, CEA Saclay, 91191 Gif-sur-Yvette (France)

    2012-03-01

    A new adaptive mesh refinement (AMR) version of the ZEUS-3D astrophysical magnetohydrodynamical fluid code, AZEuS, is described. The AMR module in AZEuS has been completely adapted to the staggered mesh that characterizes the ZEUS family of codes on which scalar quantities are zone-centered and vector components are face-centered. In addition, for applications using static grids, it is necessary to use higher-order interpolations for prolongation to minimize the errors caused by waves crossing from a grid of one resolution to another. Finally, solutions to test problems in one, two, and three dimensions in both Cartesian and spherical coordinates are presented.

  15. Midcourse Refinements of Financing Strategies | Department of...

    Office of Energy Efficiency and Renewable Energy (EERE) (indexed site)

    March 29, 2012. During this webinar participants discussed how programs have adapted and refined their financing strategies based on initial implementation experience and learning. ...

  16. Compact Mesh Generator

    Energy Science and Technology Software Center (OSTI)

    2007-02-02

    The CMG is a small, lightweight, structured mesh generation code. It features a simple text input parser that allows setup of various meshes via a small set of text commands. Mesh generation data can be output to text, the silo file format, or the API can be directly queried by applications. It can run serially or in parallel via MPI. The CMG includes the ability to specify varius initial conditions on a mesh via meshmore » tags.« less

  17. phdMesh

    Energy Science and Technology Software Center (OSTI)

    2008-01-01

    Parallel Heterogeneous Dynamic unstructured Mesh (phdMesh) data structure library and integration testing code that performs dynamic load balancing of the data structure and parallel geometric proximity search on a contrived test problem. The phdMesh library is intended to be module within a finite element or finite volume library or code. The integration testing code is intended to provide a compact and highly portable performance evaluation code for parallel computing systems.

  18. Refiner Crude Oil Inputs

    U.S. Energy Information Administration (EIA) (indexed site)

    Net Inputs (Refiner and Blender) of RBOB Blending Components Net Inputs (Refiner and Blender) of CBOB Blending Components Net Inputs (Refiner and Blender) of GTAB Blending ...

  19. Optimization of tetrahedral meshes

    SciTech Connect (OSTI)

    Briere De L`Isle, E.; George, P.L.

    1995-12-31

    Finite element computations are all the more exact if we start from {open_quotes}good{close_quotes} elements. We are interested in meshes where the elements are tetrahedra and we shall develop utilities allowing us to improve the quality of these meshes.

  20. Parallel partitioning strategies for the adaptive solution of conservation laws

    SciTech Connect (OSTI)

    Devine, K.D.; Flaherty, J.E.; Loy, R.M.

    1995-12-31

    We describe and examine the performance of adaptive methods for Solving hyperbolic systems of conservation laws on massively parallel computers. The differential system is approximated by a discontinuous Galerkin finite element method with a hierarchical Legendre piecewise polynomial basis for the spatial discretization. Fluxes at element boundaries are computed by solving an approximate Riemann problem; a projection limiter is applied to keep the average solution monotone; time discretization is performed by Runge-Kutta integration; and a p-refinement-based error estimate is used as an enrichment indicator. Adaptive order (p-) and mesh (h-) refinement algorithms are presented and demonstrated. Using an element-based dynamic load balancing algorithm called tiling and adaptive p-refinement, parallel efficiencies of over 60% are achieved on a 1024-processor nCUBE/2 hypercube. We also demonstrate a fast, tree-based parallel partitioning strategy for three-dimensional octree-structured meshes. This method produces partition quality comparable to recursive spectral bisection at a greatly reduced cost.

  1. Documentation for MeshKit - Reactor Geometry (&mesh) Generator

    SciTech Connect (OSTI)

    Jain, Rajeev; Mahadevan, Vijay

    2015-09-30

    This report gives documentation for using MeshKit’s Reactor Geometry (and mesh) Generator (RGG) GUI and also briefly documents other algorithms and tools available in MeshKit. RGG is a program designed to aid in modeling and meshing of complex/large hexagonal and rectilinear reactor cores. RGG uses Argonne’s SIGMA interfaces, Qt and VTK to produce an intuitive user interface. By integrating a 3D view of the reactor with the meshing tools and combining them into one user interface, RGG streamlines the task of preparing a simulation mesh and enables real-time feedback that reduces accidental scripting mistakes that could waste hours of meshing. RGG interfaces with MeshKit tools to consolidate the meshing process, meaning that going from model to mesh is as easy as a button click. This report is designed to explain RGG v 2.0 interface and provide users with the knowledge and skills to pilot RGG successfully. Brief documentation of MeshKit source code, tools and other algorithms available are also presented for developers to extend and add new algorithms to MeshKit. RGG tools work in serial and parallel and have been used to model complex reactor core models consisting of conical pins, load pads, several thousands of axially varying material properties of instrumentation pins and other interstices meshes.

  2. Geometric approaches to mesh generation

    SciTech Connect (OSTI)

    Hoffmann, C.M.

    1995-12-31

    We review three approaches to mesh generation that axe based on analyzing and accounting for the geometric structure of the domain. In the first approach, due to Armstrong, the domain is partitioned into subdomains based on the medial-axis transform, a tool for analyzing spatial structures. In the second approach, due to Cox, the design history defines a geometric structure of the domain. The design primitives of that structure are meshed separately, and mesh overlap is accounted for by coupling equations. The third approach argues that mesh generation ought to be integrated into the shape design process, by meshing design features separately and resolving overlapping meshes by standard geometric computations.

  3. ITP Petroleum Refining: Energy Bandwidth for Petroleum Refining Processes |

    Office of Energy Efficiency and Renewable Energy (EERE) (indexed site)

    Department of Energy Bandwidth for Petroleum Refining Processes ITP Petroleum Refining: Energy Bandwidth for Petroleum Refining Processes bandwidth.pdf (1.16 MB) More Documents & Publications ITP Petroleum Refining: Energy Bandwidth for Petroleum Refining Processes Bandwidth Study U.S. Petroleum Refining ITP Petroleum Refining: Energy and Environmental Profile of the U.S. Petroleum Refining Industry (November 2007) ITP Petroleum Refining: Profile of the Petroleum Refining Industry in

  4. conference {15169

    U.S. Department of Energy (DOE) all webpages (Extended Search)

    ... Conformal and Non-conformal Adaptive Mesh Refinement with Hierarchical Array-based ... are meshed using MeshKit tools or the CUBIT mesh generation toolkit, optionally ...

  5. %A L. A. Bautista Gomez

    U.S. Department of Energy (DOE) all webpages (Extended Search)

    ... %T Conformal and Non-conformal Adaptive Mesh Refinement with Hierarchical Array-based ... are meshed using MeshKit tools or the CUBIT mesh generation toolkit, optionally ...

  6. ALEGRA -- A massively parallel h-adaptive code for solid dynamics

    SciTech Connect (OSTI)

    Summers, R.M.; Wong, M.K.; Boucheron, E.A.; Weatherby, J.R.

    1997-12-31

    ALEGRA is a multi-material, arbitrary-Lagrangian-Eulerian (ALE) code for solid dynamics designed to run on massively parallel (MP) computers. It combines the features of modern Eulerian shock codes, such as CTH, with modern Lagrangian structural analysis codes using an unstructured grid. ALEGRA is being developed for use on the teraflop supercomputers to conduct advanced three-dimensional (3D) simulations of shock phenomena important to a variety of systems. ALEGRA was designed with the Single Program Multiple Data (SPMD) paradigm, in which the mesh is decomposed into sub-meshes so that each processor gets a single sub-mesh with approximately the same number of elements. Using this approach the authors have been able to produce a single code that can scale from one processor to thousands of processors. A current major effort is to develop efficient, high precision simulation capabilities for ALEGRA, without the computational cost of using a global highly resolved mesh, through flexible, robust h-adaptivity of finite elements. H-adaptivity is the dynamic refinement of the mesh by subdividing elements, thus changing the characteristic element size and reducing numerical error. The authors are working on several major technical challenges that must be met to make effective use of HAMMER on MP computers.

  7. SUPERIMPOSED MESH PLOTTING IN MCNP

    SciTech Connect (OSTI)

    J. HENDRICKS

    2001-02-01

    The capability to plot superimposed meshes has been added to MCNP{trademark}. MCNP4C featured a superimposed mesh weight window generator which enabled users to set up geometries without having to subdivide geometric cells for variance reduction. The variance reduction was performed with weight windows on a rectangular or cylindrical mesh superimposed over the physical geometry. Experience with the new capability was favorable but also indicated that a number of enhancements would be very beneficial, particularly a means of visualizing the mesh and its values. The mathematics for plotting the mesh and its values is described here along with a description of other upgrades.

  8. Mesh2d

    Energy Science and Technology Software Center (OSTI)

    2011-12-31

    Mesh2d is a Fortran90 program designed to generate two-dimensional structured grids of the form [x(i),y(i,j)] where [x,y] are grid coordinates identified by indices (i,j). The x(i) coordinates alone can be used to specify a one-dimensional grid. Because the x-coordinates vary only with the i index, a two-dimensional grid is composed in part of straight vertical lines. However, the nominally horizontal y(i,j0) coordinates along index i are permitted to undulate or otherwise vary. Mesh2d also assignsmore » an integer material type to each grid cell, mtyp(i,j), in a user-specified manner. The complete grid is specified through three separate input files defining the x(i), y(i,j), and mtyp(i,j) variations.« less

  9. Mesh Algorithms for PDE with Sieve I: Mesh Distribution

    DOE PAGES-Beta [OSTI]

    Knepley, Matthew G.; Karpeev, Dmitry A.

    2009-01-01

    We have developed a new programming framework, called Sieve, to support parallel numerical partial differential equation(s) (PDE) algorithms operating over distributed meshes. We have also developed a reference implementation of Sieve in C++ as a library of generic algorithms operating on distributed containers conforming to the Sieve interface. Sieve makes instances of the incidence relation, or arrows, the conceptual first-class objects represented in the containers. Further, generic algorithms acting on this arrow container are systematically used to provide natural geometric operations on the topology and also, through duality, on the data. Finally, coverings and duality are used to encode notmore » only individual meshes, but all types of hierarchies underlying PDE data structures, including multigrid and mesh partitions. In order to demonstrate the usefulness of the framework, we show how the mesh partition data can be represented and manipulated using the same fundamental mechanisms used to represent meshes. We present the complete description of an algorithm to encode a mesh partition and then distribute a mesh, which is independent of the mesh dimension, element shape, or embedding. Moreover, data associated with the mesh can be similarly distributed with exactly the same algorithm. The use of a high level of abstraction within the Sieve leads to several benefits in terms of code reuse, simplicity, and extensibility. We discuss these benefits and compare our approach to other existing mesh libraries.« less

  10. Mesh Oriented datABase

    Energy Science and Technology Software Center (OSTI)

    2004-04-01

    MOAB is a component for representing and evaluating mesh data. MOAB can store stuctured and unstructured mesh, consisting of elements in the finite element "zoo". The functional interface to MOAB is simple yet powerful, allowing the representation of many types of metadata commonly found on the mesh. MOAB is optimized for efficiency in space and time, based on access to mesh in chunks rather than through individual entities, while also versatile enough to support individualmore » entity access. The MOAB data model consists of a mesh interface instance, mesh entities (vertices and elements), sets, and tags. Entities are addressed through handles rather than pointers, to allow the underlying representation of an entity to change without changing the handle to that entity. Sets are arbitrary groupings of mesh entities and other sets. Sets also support parent/child relationships as a relation distinct from sets containing other sets. The directed-graph provided by set parent/child relationships is useful for modeling topological relations from a geometric model or other metadata. Tags are named data which can be assigned to the mesh as a whole, individual entities, or sets. Tags are a mechanism for attaching data to individual entities and sets are a mechanism for describing relations between entities; the combination of these two mechanisms isa powerful yet simple interface for representing metadata or application-specific data. For example, sets and tags can be used together to describe geometric topology, boundary condition, and inter-processor interface groupings in a mesh. MOAB is used in several ways in various applications. MOAB serves as the underlying mesh data representation in the VERDE mesh verification code. MOAB can also be used as a mesh input mechanism, using mesh readers induded with MOAB, or as a t’anslator between mesh formats, using readers and writers included with MOAB.« less

  11. ITP Petroleum Refining: Energy Bandwidth for Petroleum Refining...

    Office of Energy Efficiency and Renewable Energy (EERE) (indexed site)

    Bandwidth for Petroleum Refining Processes ITP Petroleum Refining: Energy Bandwidth for Petroleum Refining Processes bandwidth.pdf (1.16 MB) More Documents & Publications ITP ...

  12. ITP Petroleum Refining: Profile of the Petroleum Refining Industry...

    Office of Energy Efficiency and Renewable Energy (EERE) (indexed site)

    Profile of the Petroleum Refining Industry in California: California Industries of the Future Program ITP Petroleum Refining: Profile of the Petroleum Refining Industry in ...

  13. Creating Interoperable Meshing and Discretization Software: The Terascale Simulation Tools and Technology Center

    SciTech Connect (OSTI)

    Brown, D.; Freitag, L.; Glimm, J.

    2002-03-28

    We present an overview of the technical objectives of the Terascale Simulation Tools and Technologies center. The primary goal of this multi-institution collaboration is to develop technologies that enable application scientists to easily use multiple mesh and discretization strategies within a single simulation on terascale computers. The discussion focuses on our efforts to create interoperable mesh generation tools, high-order discretization techniques, and adaptive meshing strategies.

  14. CREATING INTEROPERABLE MESHING AND DISCRETIZATION SOFTWARE: THE TERASCALE SIMULATION TOOLS AND TECHNOLOGY CENTER.

    SciTech Connect (OSTI)

    BROWN,D.; FREITAG,L.; GLIMM,J.

    2002-06-02

    We present an overview of the technical objectives of the Terascale Simulation Tools and Technologies center. The primary goal of this multi-institution collaboration is to develop technologies that enable application scientists to easily use multiple mesh and discretization strategies within a single simulation on terascale computers. The discussion focuses on our efforts to create interoperable mesh generation tools, high-order discretization techniques, and adaptive meshing strategies.

  15. Step 3: Project Refinement

    Office of Energy Efficiency and Renewable Energy (EERE) (indexed site)

    3: Project Refinement 2 1 Potential 3 Refinement 4 Implementation 5 Operations & Maintenance 2 Options 3 Refinement 1/28/2016 2 3 FUNDING AND FINANCING OPTIONS Project Ownership Financing structure is highly dependent on size of the project and the capital available for a given project: * Tribe owns the project (cash purchase or debt) * Tribe hosts the project and buys the electricity (power purchase agreement) * Tribe partners with private sector and co-owns the project (uncertainties about

  16. Spherical geodesic mesh generation (Conference) | SciTech Connect

    Office of Scientific and Technical Information (OSTI)

    In ALE simulations with moving meshes, mesh topology has a direct influence on feature ... This mesh topology is fundamentally different from traditional mesh topologies and ...

  17. Quadrilateral finite element mesh coarsening

    DOE Patents [OSTI]

    Staten, Matthew L; Dewey, Mark W; Benzley, Steven E

    2012-10-16

    Techniques for coarsening a quadrilateral mesh are described. These techniques include identifying a coarsening region within the quadrilateral mesh to be coarsened. Quadrilateral elements along a path through the coarsening region are removed. Node pairs along opposite sides of the path are identified. The node pairs along the path are then merged to collapse the path.

  18. Refiners trade hydroprocessing experience

    SciTech Connect (OSTI)

    Not Available

    1984-04-16

    Hydrogen treating and conversion processes less severe than hydrocracking abound in most refineries and therefore were a subject of high interest at the National Petroleum Refiners Association question and answer session on refining technology. The present paper, which is the second abstract of the transcript of the most recent meeting, covers hydroprocessing and some of its mechanical, process, and catalytic aspects.

  19. Collaboration Topics - Meshing | National Nuclear Security Administration |

    National Nuclear Security Administration (NNSA)

    (NNSA) Meshing This work focuses on automatic algorithms for 3-D mesh generation and their extension to scalable parallel environments. The objective is to explore new theoretical advancements and develop new algorithms in mesh generation that will lead to practical advances in automatic meshing with an emphasis on all-hexahedral mesh generation technology. The development of technologies to facilitate model preparation for analysis such as CAD support for meshing and geometry simplification

  20. Nanowire mesh solar fuels generator

    DOE Patents [OSTI]

    Yang, Peidong; Chan, Candace; Sun, Jianwei; Liu, Bin

    2016-05-24

    This disclosure provides systems, methods, and apparatus related to a nanowire mesh solar fuels generator. In one aspect, a nanowire mesh solar fuels generator includes (1) a photoanode configured to perform water oxidation and (2) a photocathode configured to perform water reduction. The photocathode is in electrical contact with the photoanode. The photoanode may include a high surface area network of photoanode nanowires. The photocathode may include a high surface area network of photocathode nanowires. In some embodiments, the nanowire mesh solar fuels generator may include an ion conductive polymer infiltrating the photoanode and the photocathode in the region where the photocathode is in electrical contact with the photoanode.

  1. Toward Interoperable Mesh, Geometry and Field Components for PDE Simulation Development

    SciTech Connect (OSTI)

    Chand, K K; Diachin, L F; Li, X; Ollivier-Gooch, C; Seol, E S; Shephard, M; Tautges, T; Trease, H

    2005-07-11

    Mesh-based PDE simulation codes are becoming increasingly sophisticated and rely on advanced meshing and discretization tools. Unfortunately, it is still difficult to interchange or interoperate tools developed by different communities to experiment with various technologies or to develop new capabilities. To address these difficulties, we have developed component interfaces designed to support the information flow of mesh-based PDE simulations. We describe this information flow and discuss typical roles and services provided by the geometry, mesh, and field components of the simulation. Based on this delineation for the roles of each component, we give a high-level description of the abstract data model and set of interfaces developed by the Department of Energy's Interoperable Tools for Advanced Petascale Simulation (ITAPS) center. These common interfaces are critical to our interoperability goal, and we give examples of several services based upon these interfaces including mesh adaptation and mesh improvement.

  2. NAFTA opportunities: Petroleum refining

    SciTech Connect (OSTI)

    Not Available

    1993-01-01

    The North American Free Trade Agreement (NAFTA) creates a more transparent environment for the sale of refined petroleum products to Mexico, and locks in access to Canada's relatively open market for these products. Canada and Mexico are sizable United States export markets for refined petroleum products, with exports of $556 million and $864 million, respectively, in 1992. These markets represent approximately 24 percent of total U.S. exports of these goods.

  3. Multilevel adaptive solution procedure for material nonlinear problems in visual programming environment

    SciTech Connect (OSTI)

    Kim, D.; Ghanem, R.

    1994-12-31

    Multigrid solution technique to solve a material nonlinear problem in a visual programming environment using the finite element method is discussed. The nonlinear equation of equilibrium is linearized to incremental form using Newton-Rapson technique, then multigrid solution technique is used to solve linear equations at each Newton-Rapson step. In the process, adaptive mesh refinement, which is based on the bisection of a pair of triangles, is used to form grid hierarchy for multigrid iteration. The solution process is implemented in a visual programming environment with distributed computing capability, which enables more intuitive understanding of solution process, and more effective use of resources.

  4. User Manual for the PROTEUS Mesh Tools

    SciTech Connect (OSTI)

    Smith, Micheal A.; Shemon, Emily R.

    2015-06-01

    This report describes the various mesh tools that are provided with the PROTEUS code giving both descriptions of the input and output. In many cases the examples are provided with a regression test of the mesh tools. The most important mesh tools for any user to consider using are the MT_MeshToMesh.x and the MT_RadialLattice.x codes. The former allows the conversion between most mesh types handled by PROTEUS while the second allows the merging of multiple (assembly) meshes into a radial structured grid. Note that the mesh generation process is recursive in nature and that each input specific for a given mesh tool (such as .axial or .merge) can be used as “mesh” input for any of the mesh tools discussed in this manual.

  5. SAMRAI V3.1

    Energy Science and Technology Software Center (OSTI)

    001825MLTPL01 Structured Adaptive Mesh Refinement Application Infrastructure https://computation.llnl.gov/casc/samrai

  6. A Discontinuous Petrov-Galerkin Methodology for Adaptive Solutions to the Incompressible Navier-Stokes Equations

    SciTech Connect (OSTI)

    Roberts, Nathan V.; Demkowiz, Leszek; Moser, Robert

    2015-11-15

    The discontinuous Petrov-Galerkin methodology with optimal test functions (DPG) of Demkowicz and Gopalakrishnan [18, 20] guarantees the optimality of the solution in an energy norm, and provides several features facilitating adaptive schemes. Whereas Bubnov-Galerkin methods use identical trial and test spaces, Petrov-Galerkin methods allow these function spaces to differ. In DPG, test functions are computed on the fly and are chosen to realize the supremum in the inf-sup condition; the method is equivalent to a minimum residual method. For well-posed problems with sufficiently regular solutions, DPG can be shown to converge at optimal rates—the inf-sup constants governing the convergence are mesh-independent, and of the same order as those governing the continuous problem [48]. DPG also provides an accurate mechanism for measuring the error, and this can be used to drive adaptive mesh refinements. We employ DPG to solve the steady incompressible Navier-Stokes equations in two dimensions, building on previous work on the Stokes equations, and focusing particularly on the usefulness of the approach for automatic adaptivity starting from a coarse mesh. We apply our approach to a manufactured solution due to Kovasznay as well as the lid-driven cavity flow, backward-facing step, and flow past a cylinder problems.

  7. ITP Petroleum Refining: Profile of the Petroleum Refining Industry in

    Office of Energy Efficiency and Renewable Energy (EERE) (indexed site)

    California: California Industries of the Future Program | Department of Energy Profile of the Petroleum Refining Industry in California: California Industries of the Future Program ITP Petroleum Refining: Profile of the Petroleum Refining Industry in California: California Industries of the Future Program cpi_profile.pdf (363.14 KB) More Documents & Publications ITP Petroleum Refining: Energy and Environmental Profile of the U.S. Petroleum Refining Industry (November 2007) ITP Petroleum

  8. Self-Organizing Mesh Generation

    Energy Science and Technology Software Center (OSTI)

    1991-11-01

    A set of five programs which make up a self organizing mesh generation package. QMESH generates meshes having quadrilateral elements on arbitrarily shaped two-dimensional (planar or axisymmetric) bodies. It is designed for use with two-dimensional finite element analysis applications. A flexible hierarchal input scheme is used to describe bodies to QMESH as collections of regions. A mesh for each region is developed independently, with the final assembly and bandwidth minimization performed by the independent program,more » RENUM or RENUM8. RENUM is applied when four-node elements are desired. Eight node elements (with mid side nodes) may be obtained with RENUM8. QPLOT and QPLOT8 are plot programs for meshes generated by the QMESH/RENUM and QMESH/RENUM8 program pairs respectively. QPLOT and QPLOT8 automatically section the mesh into appropriately-sized sections for legible display of node and element numbers, An overall plot showing the position of the selected plot areas is produced.« less

  9. Cache-oblivious mesh layouts

    SciTech Connect (OSTI)

    Yoon, Sung-Eui; Lindstrom, Peter; Pascucci, Valerio; Manocha, Dinesh

    2005-07-01

    We present a novel method for computing cache-oblivious layouts of large meshes that improve the performance of interactive visualization and geometric processing algorithms. Given that the mesh is accessed in a reasonably coherent manner, we assume no particular data access patterns or cache parameters of the memory hierarchy involved in the computation. Furthermore, our formulation extends directly to computing layouts of multi-resolution and bounding volume hierarchies of large meshes. We develop a simple and practical cache-oblivious metric for estimating cache misses. Computing a coherent mesh layout is reduced to a combinatorial optimization problem. We designed and implemented an out-of-core multilevel minimization algorithm and tested its performance on unstructured meshes composed of tens to hundreds of millions of triangles. Our layouts can significantly reduce the number of cache misses. We have observed 2-20 times speedups in view-dependent rendering, collision detection, and isocontour extraction without any modification of the algorithms or runtime applications.

  10. MeshMaker: Configurable Meshing Framework for Eco-Hydrology Models

    DOE Data Explorer [Office of Scientific and Technical Information (OSTI)]

    Nathan Collier; Jitendra Kumar

    2016-02-09

    MeshMaker is a Python-based framework for generation of high quality structured and unstructured grid computational meshes for Eco-Hydrological models.

  11. Spherical geodesic mesh generation (Conference) | SciTech Connect

    Office of Scientific and Technical Information (OSTI)

    This mesh topology is fundamentally different from traditional mesh topologies and displays superior qualities such as topological symmetry. This work describes the geodesic mesh ...

  12. Simulation of single mode Richtmyer-Meshkov instability using the adaptive free Lagrange method

    SciTech Connect (OSTI)

    Burton, D.E.; Harrison, A.K.

    1991-06-01

    Because of extreme deformation, instability problems have been traditionally modeled using Eulerian techniques or Arbitrary Lagrange Euler (ALE) techniques. The free-Lagrange (FL) method first introduced by Crowley offers a third basic alternative. The specific FL method described in this paper consists of: (1) a 2D staggered-grid hydrodynamics (SGH) differencing scheme appropriate to an unstructured mesh consisting of triangular and quadrilateral zones; (2) a set of primitive mesh optimization algorithms; and (3) a set of rules for adaptive mesh refinement which we refer to as the adaptive free Lagrange (AFL) method. In a previous study, Burton showed that the spurious vorticity commonly associated with SGH differencing results from a failure to explicity conserve angular momentum in the difference equations. This led to a significantly improved technique for removing the spurious vorticity, called spurious vorticity damping (SVD). SVD was shown to produce superior results in a test problem which had no intrinsic vorticity. In the present study, SVD is shown to also produce superior results in a problem with intrinsic vorticity. The AFL and SVD methods are applied to a low Mach number shock tube problem and compared with other methods. AFL seems to perform as well as Eulerian methods and is somewhat better at resolving fine structures in the calculation. The SVD method produced results far superior to other methods tried. 21 refs., 10 figs.

  13. Petroleum Refining | Department of Energy

    Office of Energy Efficiency and Renewable Energy (EERE) (indexed site)

    Petroleum Refining Petroleum Refining Maintaining the viability of the U.S. petroleum refining industry requires continuous improvement in productivity and energy efficiency. The U.S. refining industry has worked with AMO to provide a range of resources that can provide energy and cost savings for the industry. Analytical Studies & Other Publications Manufacturing Energy and Carbon Footprints provide a mapping of energy use, energy loss, and carbon emissions for selected industry sectors.

  14. Adaptive Materials Design

    U.S. Department of Energy (DOE) all webpages (Extended Search)

    4 » Adaptive Materials Design Adaptive Materials Design An active learning paradigm for materials. Contact Turab Lookman Email Adaptive learning for accelerated materials discovery Materials design and discovery guided by community-driven active user interface, where data from users is utilized to refine predictions for optimally guiding next experiments or computations. This portal showcases some of our unique capabilities in advancing materials design within the adaptive design framework.

  15. A Parallel Ghosting Algorithm for The Flexible Distributed Mesh Database

    DOE PAGES-Beta [OSTI]

    Mubarak, Misbah; Seol, Seegyoung; Lu, Qiukai; Shephard, Mark S.

    2013-01-01

    Critical to the scalability of parallel adaptive simulations are parallel control functions including load balancing, reduced inter-process communication and optimal data decomposition. In distributed meshes, many mesh-based applications frequently access neighborhood information for computational purposes which must be transmitted efficiently to avoid parallel performance degradation when the neighbors are on different processors. This article presents a parallel algorithm of creating and deleting data copies, referred to as ghost copies, which localize neighborhood data for computation purposes while minimizing inter-process communication. The key characteristics of the algorithm are: (1) It can create ghost copies of any permissible topological order inmore » a 1D, 2D or 3D mesh based on selected adjacencies. (2) It exploits neighborhood communication patterns during the ghost creation process thus eliminating all-to-all communication. (3) For applications that need neighbors of neighbors, the algorithm can create n number of ghost layers up to a point where the whole partitioned mesh can be ghosted. Strong and weak scaling results are presented for the IBM BG/P and Cray XE6 architectures up to a core count of 32,768 processors. The algorithm also leads to scalable results when used in a parallel super-convergent patch recovery error estimator, an application that frequently accesses neighborhood data to carry out computation.« less

  16. Minimally refined biomass fuel

    DOE Patents [OSTI]

    Pearson, Richard K.; Hirschfeld, Tomas B.

    1984-01-01

    A minimally refined fluid composition, suitable as a fuel mixture and derived from biomass material, is comprised of one or more water-soluble carbohydrates such as sucrose, one or more alcohols having less than four carbons, and water. The carbohydrate provides the fuel source; water solubilizes the carbohydrates; and the alcohol aids in the combustion of the carbohydrate and reduces the vicosity of the carbohydrate/water solution. Because less energy is required to obtain the carbohydrate from the raw biomass than alcohol, an overall energy savings is realized compared to fuels employing alcohol as the primary fuel.

  17. Local, Optimization-based Simplicial Mesh Smoothing

    Energy Science and Technology Software Center (OSTI)

    1999-12-09

    OPT-MS is a C software package for the improvement and untangling of simplicial meshes (triangles in 2D, tetrahedra in 3D). Overall mesh quality is improved by iterating over the mesh vertices and adjusting their position to optimize some measure of mesh quality, such as element angle or aspect ratio. Several solution techniques (including Laplacian smoothing, "Smart" Laplacian smoothing, optimization-based smoothing and several combinations thereof) and objective functions (for example, element angle, sin (angle), and aspectmore » ratio) are available to the user for both two and three-dimensional meshes. If the mesh contains invalid elements (those with negative area) a different optimization algorithm for mesh untangling is provided.« less

  18. SHARP/PRONGHORN Interoperability: Mesh Generation

    SciTech Connect (OSTI)

    Avery Bingham; Javier Ortensi

    2012-09-01

    Progress toward collaboration between the SHARP and MOOSE computational frameworks has been demonstrated through sharing of mesh generation and ensuring mesh compatibility of both tools with MeshKit. MeshKit was used to build a three-dimensional, full-core very high temperature reactor (VHTR) reactor geometry with 120-degree symmetry, which was used to solve a neutron diffusion critical eigenvalue problem in PRONGHORN. PRONGHORN is an application of MOOSE that is capable of solving coupled neutron diffusion, heat conduction, and homogenized flow problems. The results were compared to a solution found on a 120-degree, reflected, three-dimensional VHTR mesh geometry generated by PRONGHORN. The ability to exchange compatible mesh geometries between the two codes is instrumental for future collaboration and interoperability. The results were found to be in good agreement between the two meshes, thus demonstrating the compatibility of the SHARP and MOOSE frameworks. This outcome makes future collaboration possible.

  19. Message Passing for Linux Clusters with Gigabit Ethernet Mesh Connections

    SciTech Connect (OSTI)

    Jie Chen; Chip Watson; Robert Edwards; Weizhen Mao

    2005-04-01

    Multiple copper-based commodity Gigabit Ethernet (GigE) interconnects (adapters) on a single host can lead to Linux clusters with mesh/torus connections without using expensive switches and high speed network interconnects (NICs). However traditional message passing systems based on TCP for GigE will not perform well for this type of clusters because of the overhead of TCP for multiple GigE links. In this paper, we present two os-bypass message passing systems that are based on a modified M-VIA (an implementation of VIA specification) for two production GigE mesh clusters: one is constructed as a 4 x 8 x 8 (256 nodes) torus and has been in production use for a year; the other is constructed as a 6 x 8 x 8 (384 nodes) torus and was deployed recently. One of the message passing systems targets to a specific application domain and is called QMP and the other is an implementation of MPI specification 1.1. The GigE mesh clusters using these two message passing systems achieve about 18.5 {micro}s half-way round trip latency and 400MB/s total bandwidth, which compare reasonably well to systems using specialized high speed adapters in a switched architecture at much lower costs.

  20. Introducing Enabling Computational Tools to the Climate Sciences: Multi-Resolution Climate Modeling with Adaptive Cubed-Sphere Grids

    SciTech Connect (OSTI)

    Jablonowski, Christiane

    2015-07-14

    The research investigates and advances strategies how to bridge the scale discrepancies between local, regional and global phenomena in climate models without the prohibitive computational costs of global cloud-resolving simulations. In particular, the research explores new frontiers in computational geoscience by introducing high-order Adaptive Mesh Refinement (AMR) techniques into climate research. AMR and statically-adapted variable-resolution approaches represent an emerging trend for atmospheric models and are likely to become the new norm in future-generation weather and climate models. The research advances the understanding of multi-scale interactions in the climate system and showcases a pathway how to model these interactions effectively with advanced computational tools, like the Chombo AMR library developed at the Lawrence Berkeley National Laboratory. The research is interdisciplinary and combines applied mathematics, scientific computing and the atmospheric sciences. In this research project, a hierarchy of high-order atmospheric models on cubed-sphere computational grids have been developed that serve as an algorithmic prototype for the finite-volume solution-adaptive Chombo-AMR approach. The foci of the investigations have lied on the characteristics of both static mesh adaptations and dynamically-adaptive grids that can capture flow fields of interest like tropical cyclones. Six research themes have been chosen. These are (1) the introduction of adaptive mesh refinement techniques into the climate sciences, (2) advanced algorithms for nonhydrostatic atmospheric dynamical cores, (3) an assessment of the interplay between resolved-scale dynamical motions and subgrid-scale physical parameterizations, (4) evaluation techniques for atmospheric model hierarchies, (5) the comparison of AMR refinement strategies and (6) tropical cyclone studies with a focus on multi-scale interactions and variable-resolution modeling. The results of this research project

  1. Refines Efficiency Improvement

    SciTech Connect (OSTI)

    WRI

    2002-05-15

    Refinery processes that convert heavy oils to lighter distillate fuels require heating for distillation, hydrogen addition or carbon rejection (coking). Efficiency is limited by the formation of insoluble carbon-rich coke deposits. Heat exchangers and other refinery units must be shut down for mechanical coke removal, resulting in a significant loss of output and revenue. When a residuum is heated above the temperature at which pyrolysis occurs (340 C, 650 F), there is typically an induction period before coke formation begins (Magaril and Aksenova 1968, Wiehe 1993). To avoid fouling, refiners often stop heating a residuum before coke formation begins, using arbitrary criteria. In many cases, this heating is stopped sooner than need be, resulting in less than maximum product yield. Western Research Institute (WRI) has developed innovative Coking Index concepts (patent pending) which can be used for process control by refiners to heat residua to the threshold, but not beyond the point at which coke formation begins when petroleum residua materials are heated at pyrolysis temperatures (Schabron et al. 2001). The development of this universal predictor solves a long standing problem in petroleum refining. These Coking Indexes have great potential value in improving the efficiency of distillation processes. The Coking Indexes were found to apply to residua in a universal manner, and the theoretical basis for the indexes has been established (Schabron et al. 2001a, 2001b, 2001c). For the first time, a few simple measurements indicates how close undesired coke formation is on the coke formation induction time line. The Coking Indexes can lead to new process controls that can improve refinery distillation efficiency by several percentage points. Petroleum residua consist of an ordered continuum of solvated polar materials usually referred to as asphaltenes dispersed in a lower polarity solvent phase held together by intermediate polarity materials usually referred to as

  2. TAP - Tools for Adaptive Partitioning v. 0.99 Beta

    Energy Science and Technology Software Center (OSTI)

    2008-11-19

    TAP is a set of tools which are essential for conducting research on adaptive partitioners. The basic premise is that a single partitioner may not be a good choice for adaptive mesh simulations; rather one must match a partitioner (obtained from a partitioning package like Zoltan, ParMetis etc) with the mesh being partitioned. TAP provides the tools that can judge the suitability of a partitioning algorithm to a given mesh.

  3. ITP Petroleum Refining: Energy Bandwidth for Petroleum Refining...

    Office of Energy Efficiency and Renewable Energy (EERE) (indexed site)

    Bandwidth for Petroleum Refining Processes Prepared by Energetics Incorporated for the U.S. Department of Energy Office of Energy Efficiency and Renewable Energy Industrial ...

  4. The value of continuity: Refined isogeometric analysis and fast direct solvers

    DOE PAGES-Beta [OSTI]

    Garcia, Daniel; Pardo, David; Dalcin, Lisandro; Paszynski, Maciej; Collier, Nathan; Calo, Victor M.

    2016-08-24

    Here, we propose the use of highly continuous finite element spaces interconnected with low continuity hyperplanes to maximize the performance of direct solvers. Starting from a highly continuous Isogeometric Analysis (IGA) discretization, we introduce C0-separators to reduce the interconnection between degrees of freedom in the mesh. By doing so, both the solution time and best approximation errors are simultaneously improved. We call the resulting method “refined Isogeometric Analysis (rIGA)”. To illustrate the impact of the continuity reduction, we analyze the number of Floating Point Operations (FLOPs), computational times, and memory required to solve the linear system obtained by discretizing themore » Laplace problem with structured meshes and uniform polynomial orders. Theoretical estimates demonstrate that an optimal continuity reduction may decrease the total computational time by a factor between p2 and p3, with pp being the polynomial order of the discretization. Numerical results indicate that our proposed refined isogeometric analysis delivers a speed-up factor proportional to p2. In a 2D mesh with four million elements and p=5, the linear system resulting from rIGA is solved 22 times faster than the one from highly continuous IGA. In a 3D mesh with one million elements and p=3, the linear system is solved 15 times faster for the refined than the maximum continuity isogeometric analysis.« less

  5. Mesh infrastructure for coupled multiprocess geophysical simulations

    SciTech Connect (OSTI)

    Garimella, Rao V.; Perkins, William A.; Buksas, Mike W.; Berndt, Markus; Lipnikov, Konstantin; Coon, Ethan; Moulton, John D.; Painter, Scott L.

    2014-01-01

    We have developed a sophisticated mesh infrastructure capability to support large scale multiphysics simulations such as subsurface flow and reactive contaminant transport at storage sites as well as the analysis of the effects of a warming climate on the terrestrial arctic. These simulations involve a wide range of coupled processes including overland flow, subsurface flow, freezing and thawing of ice rich soil, accumulation, redistribution and melting of snow, biogeochemical processes involving plant matter and finally, microtopography evolution due to melting and degradation of ice wedges below the surface. In addition to supporting the usual topological and geometric queries about the mesh, the mesh infrastructure adds capabilities such as identifying columnar structures in the mesh, enabling deforming of the mesh subject to constraints and enabling the simultaneous use of meshes of different dimensionality for subsurface and surface processes. The generic mesh interface is capable of using three different open source mesh frameworks (MSTK, MOAB and STKmesh) under the hood allowing the developers to directly compare them and choose one that is best suited for the application's needs. We demonstrate the results of some simulations using these capabilities as well as present a comparison of the performance of the different mesh frameworks.

  6. Collaboration Topics - Meshing | National Nuclear Security Administrat...

    National Nuclear Security Administration (NNSA)

    The development of technologies to facilitate model preparation for analysis such as CAD support for meshing and geometry simplification are also within the scope of this joint ...

  7. Mesh infrastructure for coupled multiprocess geophysical simulations

    DOE PAGES-Beta [OSTI]

    Garimella, Rao V.; Perkins, William A.; Buksas, Mike W.; Berndt, Markus; Lipnikov, Konstantin; Coon, Ethan; Moulton, John D.; Painter, Scott L.

    2014-01-01

    We have developed a sophisticated mesh infrastructure capability to support large scale multiphysics simulations such as subsurface flow and reactive contaminant transport at storage sites as well as the analysis of the effects of a warming climate on the terrestrial arctic. These simulations involve a wide range of coupled processes including overland flow, subsurface flow, freezing and thawing of ice rich soil, accumulation, redistribution and melting of snow, biogeochemical processes involving plant matter and finally, microtopography evolution due to melting and degradation of ice wedges below the surface. In addition to supporting the usual topological and geometric queries about themore » mesh, the mesh infrastructure adds capabilities such as identifying columnar structures in the mesh, enabling deforming of the mesh subject to constraints and enabling the simultaneous use of meshes of different dimensionality for subsurface and surface processes. The generic mesh interface is capable of using three different open source mesh frameworks (MSTK, MOAB and STKmesh) under the hood allowing the developers to directly compare them and choose one that is best suited for the application's needs. We demonstrate the results of some simulations using these capabilities as well as present a comparison of the performance of the different mesh frameworks.« less

  8. RGG: Reactor geometry (and mesh) generator

    SciTech Connect (OSTI)

    Jain, R.; Tautges, T.

    2012-07-01

    The reactor geometry (and mesh) generator RGG takes advantage of information about repeated structures in both assembly and core lattices to simplify the creation of geometry and mesh. It is released as open source software as a part of the MeshKit mesh generation library. The methodology operates in three stages. First, assembly geometry models of various types are generated by a tool called AssyGen. Next, the assembly model or models are meshed by using MeshKit tools or the CUBIT mesh generation tool-kit, optionally based on a journal file output by AssyGen. After one or more assembly model meshes have been constructed, a tool called CoreGen uses a copy/move/merge process to arrange the model meshes into a core model. In this paper, we present the current state of tools and new features in RGG. We also discuss the parallel-enabled CoreGen, which in several cases achieves super-linear speedups since the problems fit in available RAM at higher processor counts. Several RGG applications - 1/6 VHTR model, 1/4 PWR reactor core, and a full-core model for Monju - are reported. (authors)

  9. Method of generating a surface mesh

    DOE Patents [OSTI]

    Shepherd, Jason F.; Benzley, Steven; Grover, Benjamin T.

    2008-03-04

    A method and machine-readable medium provide a technique to generate and modify a quadrilateral finite element surface mesh using dual creation and modification. After generating a dual of a surface (mesh), a predetermined algorithm may be followed to generate and modify a surface mesh of quadrilateral elements. The predetermined algorithm may include the steps of generating two-dimensional cell regions in dual space, determining existing nodes in primal space, generating new nodes in the dual space, and connecting nodes to form the quadrilateral elements (faces) for the generated and modifiable surface mesh.

  10. MOAB : a mesh-oriented database.

    SciTech Connect (OSTI)

    Tautges, Timothy James; Ernst, Corey; Stimpson, Clint; Meyers, Ray J.; Merkley, Karl

    2004-04-01

    A finite element mesh is used to decompose a continuous domain into a discretized representation. The finite element method solves PDEs on this mesh by modeling complex functions as a set of simple basis functions with coefficients at mesh vertices and prescribed continuity between elements. The mesh is one of the fundamental types of data linking the various tools in the FEA process (mesh generation, analysis, visualization, etc.). Thus, the representation of mesh data and operations on those data play a very important role in FEA-based simulations. MOAB is a component for representing and evaluating mesh data. MOAB can store structured and unstructured mesh, consisting of elements in the finite element 'zoo'. The functional interface to MOAB is simple yet powerful, allowing the representation of many types of metadata commonly found on the mesh. MOAB is optimized for efficiency in space and time, based on access to mesh in chunks rather than through individual entities, while also versatile enough to support individual entity access. The MOAB data model consists of a mesh interface instance, mesh entities (vertices and elements), sets, and tags. Entities are addressed through handles rather than pointers, to allow the underlying representation of an entity to change without changing the handle to that entity. Sets are arbitrary groupings of mesh entities and other sets. Sets also support parent/child relationships as a relation distinct from sets containing other sets. The directed-graph provided by set parent/child relationships is useful for modeling topological relations from a geometric model or other metadata. Tags are named data which can be assigned to the mesh as a whole, individual entities, or sets. Tags are a mechanism for attaching data to individual entities and sets are a mechanism for describing relations between entities; the combination of these two mechanisms is a powerful yet simple interface for representing metadata or application

  11. Massively parallel mesh generation for physics codes

    SciTech Connect (OSTI)

    Hardin, D.D.

    1996-06-01

    Massively parallel processors (MPPs) will soon enable realistic 3-D physical modeling of complex objects and systems. Work is planned or presently underway to port many of LLNL`s physical modeling codes to MPPs. LLNL`s DSI3D electromagnetics code already can solve 40+ million zone problems on the 256 processor Meiko. However, the author lacks the software necessary to generate and manipulate the large meshes needed to model many complicated 3-D geometries. State-of-the-art commercial mesh generators run on workstations and have a practical limit of several hundred thousand elements. In the foreseeable future MPPs will solve problems with a billion mesh elements. The objective of the Parallel Mesh Generation (PMESH) Project is to develop a unique mesh generation system that can construct large 3-D meshes (up to a billion elements) on MPPs. Such a capability will remove a critical roadblock to unleashing the power of MPPs for physical analysis and will put LLNL at the forefront of mesh generation technology. PMESH will ``front-end`` a variety of LLNL 3-D physics codes, including those in the areas of electromagnetics, structural mechanics, thermal analysis, and hydrodynamics. The DSI3D and DYNA3D codes are already running on MPPs. The primary goal of the PMESH project is to provide the robust generation of large meshes for complicated 3-D geometries through the appropriate distribution of the generation task between the user`s workstation and the MPP. Secondary goals are to support the unique features of LLNL physics codes (e.g., unusual elements) and to minimize the user effort required to generate different meshes for the same geometry. PMESH`s capabilities are essential because mesh generation is presently a major limiting factor in simulating larger and more complex 3-D geometries. PMESH will significantly enhance LLNL`s capabilities in physical simulation by advancing the state-of-the-art in large mesh generation by 2 to 3 orders of magnitude.

  12. Choosing corners of rectangles for mapped meshing

    SciTech Connect (OSTI)

    Mitchell, S.A.

    1996-12-16

    Consider mapping a regular i x j quadrilateral mesh of a rectangle onto a surface. The quality of the mapped mesh of the surface depends heavily on which vertices of the surface correspond to corners of the rectangle. The authors problem is, given an n-sided surface, chose as corners four vertices such that the surface resembles a rectangle with corners at those vertices. Note that n could be quite large, and the length and width of the rectangle, i and j, are not prespecified. In general, there is either a goal number or a prescribed number of mesh edges for each bounding curve of the surface. The goals affect the quality of the mesh, and the prescribed edges may make finding a feasible set of corners difficult. The algorithm need only work for surfaces that are roughly rectangular, particular those without large reflex angles, as otherwise an unstructured meshing algorithm is used instead. The authors report on the theory and implementation of algorithms for this problem. They also given an overview of a solution to a related problem called interval assignment: given a complex of surfaces sharing curves, globally assign the number of mesh edges or intervals for each curve such that it is possible to mesh each surface according to its prescribed quadrilateral meshing algorithm, and assigned and user-prescribed boundary mesh edges and corners. They also note a practical, constructive technique that relies on interval assignment that can generate a quadrilateral mesh of a complex of surfaces such that a compatible hexahedral mesh of the enclosed volume exists.

  13. Crystal structure refinement with SHELXL

    SciTech Connect (OSTI)

    Sheldrick, George M., E-mail: gsheldr@shelx.uni-ac.gwdg.de [Department of Structural Chemistry, Georg-August Universitt Gttingen, Tammannstrae 4, Gttingen 37077 (Germany)

    2015-01-01

    New features added to the refinement program SHELXL since 2008 are described and explained. The improvements in the crystal structure refinement program SHELXL have been closely coupled with the development and increasing importance of the CIF (Crystallographic Information Framework) format for validating and archiving crystal structures. An important simplification is that now only one file in CIF format (for convenience, referred to simply as a CIF) containing embedded reflection data and SHELXL instructions is needed for a complete structure archive; the program SHREDCIF can be used to extract the .hkl and .ins files required for further refinement with SHELXL. Recent developments in SHELXL facilitate refinement against neutron diffraction data, the treatment of H atoms, the determination of absolute structure, the input of partial structure factors and the refinement of twinned and disordered structures. SHELXL is available free to academics for the Windows, Linux and Mac OS X operating systems, and is particularly suitable for multiple-core processors.

  14. 7th International Meshing Roundtable '98

    SciTech Connect (OSTI)

    Eldred, T.J.

    1998-10-01

    The goal of the 7th International Meshing Roundtable is to bring together researchers and developers from industry, academia, and government labs in a stimulating, open environment for the exchange of technical information related to the meshing process. In the past, the Roundtable has enjoyed significant participation from each of these groups from a wide variety of countries.

  15. Feature recognition applications in mesh generation

    SciTech Connect (OSTI)

    Tautges, T.J.; Liu, S.S.; Lu, Y.; Kraftcheck, J.; Gadh, R.

    1997-06-01

    The use of feature recognition as part of an overall decomposition-based hexahedral meshing approach is described in this paper. The meshing approach consists of feature recognition, using a c-loop or hybrid c-loop method, and the use of cutting surfaces to decompose the solid model. These steps are part of an iterative process, which proceeds either until no more features can be recognized or until the model has been completely decomposed into meshable sub-volumes. This method can greatly reduce the time required to generate an all-hexahedral mesh, either through the use of more efficient meshing algorithms on more of the geometry or by reducing the amount of manual decomposition required to mesh a volume.

  16. Update on Development of Mesh Generation Algorithms in MeshKit

    SciTech Connect (OSTI)

    Jain, Rajeev; Vanderzee, Evan; Mahadevan, Vijay

    2015-09-30

    MeshKit uses a graph-based design for coding all its meshing algorithms, which includes the Reactor Geometry (and mesh) Generation (RGG) algorithms. This report highlights the developmental updates of all the algorithms, results and future work. Parallel versions of algorithms, documentation and performance results are reported. RGG GUI design was updated to incorporate new features requested by the users; boundary layer generation and parallel RGG support were added to the GUI. Key contributions to the release, upgrade and maintenance of other SIGMA1 libraries (CGM and MOAB) were made. Several fundamental meshing algorithms for creating a robust parallel meshing pipeline in MeshKit are under development. Results and current status of automated, open-source and high quality nuclear reactor assembly mesh generation algorithms such as trimesher, quadmesher, interval matching and multi-sweeper are reported.

  17. MECS 2006 - Petroleum Refining | Department of Energy

    Office of Energy Efficiency and Renewable Energy (EERE) (indexed site)

    Petroleum Refining MECS 2006 - Petroleum Refining Manufacturing Energy and Carbon Footprint for Petroleum Refining (NAICS 324110) Sector with Total Energy Input, October 2012 (MECS 2006) All available footprints and supporting documents Manufacturing Energy and Carbon Footprint Petroleum Refining (123.98 KB) More Documents & Publications Petroleum Refining (2010 MECS) MECS 2006 - Alumina and Aluminum MECS 2006 - Cement

  18. Method of modifying a volume mesh using sheet extraction

    DOE Patents [OSTI]

    Borden, Michael J.; Shepherd, Jason F.

    2007-02-20

    A method and machine-readable medium provide a technique to modify a hexahedral finite element volume mesh using dual generation and sheet extraction. After generating a dual of a volume stack (mesh), a predetermined algorithm may be followed to modify the volume mesh of hexahedral elements. The predetermined algorithm may include the steps of determining a sheet of hexahedral mesh elements, generating nodes for merging, and merging the nodes to delete the sheet of hexahedral mesh elements and modify the volume mesh.

  19. Introducing the target-matrix paradigm for mesh optimization...

    Office of Scientific and Technical Information (OSTI)

    are automatically constructed to enable definitions of application-specific mesh quality. ... that address mesh quality issues such as those shown in the examples of the present paper. ...

  20. Label-invariant Mesh Quality Metrics. (Conference) | SciTech...

    Office of Scientific and Technical Information (OSTI)

    Label-invariant Mesh Quality Metrics. Citation Details In-Document Search Title: Label-invariant Mesh Quality Metrics. Abstract not provided. Authors: Knupp, Patrick Publication ...

  1. Electronic structure of superconductivity refined

    U.S. Department of Energy (DOE) all webpages (Extended Search)

    Electronic structure of superconductivity refined Electronic structure of superconductivity refined A team of physicists propose a new model that expands on a little understood aspect of the electronic structure in high-temperature superconductors. July 10, 2008 Los Alamos National Laboratory sits on top of a once-remote mesa in northern New Mexico with the Jemez mountains as a backdrop to research and innovation covering multi-disciplines from bioscience, sustainable energy sources, to plasma

  2. Renewable Energy Financial Instruments Guidance Tool (REFINe...

    Open Energy Information (Open El) [EERE & EIA]

    Guidance Tool (REFINe) Jump to: navigation, search Tool Summary LAUNCH TOOL Name: Renewable Energy Financial Instruments Guidance Tool (REFINe) Focus Area: Renewable Energy...

  3. ,"U.S. Refiner Petroleum Product Prices"

    U.S. Energy Information Administration (EIA) (indexed site)

    ...AEPPRLPTGNUSDPG","EMAEPPRHPTGNUSDPG" "Date","U.S. Total Gasoline Retail Sales by Refiners (Dollars per Gallon)","U.S. Aviation Gasoline Retail Sales by Refiners (Dollars ...

  4. Mesh-free data transfer algorithms for partitioned multiphysics problems: Conservation, accuracy, and parallelism

    SciTech Connect (OSTI)

    Slattery, Stuart R.

    2015-12-02

    In this study we analyze and extend mesh-free algorithms for three-dimensional data transfer problems in partitioned multiphysics simulations. We first provide a direct comparison between a mesh-based weighted residual method using the common-refinement scheme and two mesh-free algorithms leveraging compactly supported radial basis functions: one using a spline interpolation and one using a moving least square reconstruction. Through the comparison we assess both the conservation and accuracy of the data transfer obtained from each of the methods. We do so for a varying set of geometries with and without curvature and sharp features and for functions with and without smoothness and with varying gradients. Our results show that the mesh-based and mesh-free algorithms are complementary with cases where each was demonstrated to perform better than the other. We then focus on the mesh-free methods by developing a set of algorithms to parallelize them based on sparse linear algebra techniques. This includes a discussion of fast parallel radius searching in point clouds and restructuring the interpolation algorithms to leverage data structures and linear algebra services designed for large distributed computing environments. The scalability of our new algorithms is demonstrated on a leadership class computing facility using a set of basic scaling studies. Finally, these scaling studies show that for problems with reasonable load balance, our new algorithms for both spline interpolation and moving least square reconstruction demonstrate both strong and weak scalability using more than 100,000 MPI processes with billions of degrees of freedom in the data transfer operation.

  5. Mesh-free data transfer algorithms for partitioned multiphysics problems: Conservation, accuracy, and parallelism

    DOE PAGES-Beta [OSTI]

    Slattery, Stuart R.

    2015-12-02

    In this study we analyze and extend mesh-free algorithms for three-dimensional data transfer problems in partitioned multiphysics simulations. We first provide a direct comparison between a mesh-based weighted residual method using the common-refinement scheme and two mesh-free algorithms leveraging compactly supported radial basis functions: one using a spline interpolation and one using a moving least square reconstruction. Through the comparison we assess both the conservation and accuracy of the data transfer obtained from each of the methods. We do so for a varying set of geometries with and without curvature and sharp features and for functions with and without smoothnessmore » and with varying gradients. Our results show that the mesh-based and mesh-free algorithms are complementary with cases where each was demonstrated to perform better than the other. We then focus on the mesh-free methods by developing a set of algorithms to parallelize them based on sparse linear algebra techniques. This includes a discussion of fast parallel radius searching in point clouds and restructuring the interpolation algorithms to leverage data structures and linear algebra services designed for large distributed computing environments. The scalability of our new algorithms is demonstrated on a leadership class computing facility using a set of basic scaling studies. Finally, these scaling studies show that for problems with reasonable load balance, our new algorithms for both spline interpolation and moving least square reconstruction demonstrate both strong and weak scalability using more than 100,000 MPI processes with billions of degrees of freedom in the data transfer operation.« less

  6. NERSC Selects 20 NESAP Code Teams

    U.S. Department of Energy (DOE) all webpages (Extended Search)

    particle-mesh algorithms, adaptive mesh refinement techniques, molecular dynamics, eigenvalue problems for complex molecular systems and ab initio computational chemistry methods. ...

  7. ASC eNews Quarterly Newsletter March 2013 | National Nuclear...

    National Nuclear Security Administration (NNSA)

    ... Support for CUBIT (a geometry and mesh-generation toolkit produced at Sandia) has been expanded to ... (2012). "Building Adaptive Mesh Refinement into a Multiphysics Code: Software ...

  8. S A N D I A M I S S I O N

    U.S. Department of Energy (DOE) all webpages (Extended Search)

    ... code, CTH, and applying adaptive mesh refinement to resolve phenomena across spatial ... meshing capabilities in Cubit and the workflow capabilities of ...

  9. Parallel octree-based hexahedral mesh generation for eulerian to lagrangian conversion.

    SciTech Connect (OSTI)

    Staten, Matthew L.; Owen, Steven James

    2010-09-01

    Computational simulation must often be performed on domains where materials are represented as scalar quantities or volume fractions at cell centers of an octree-based grid. Common examples include bio-medical, geotechnical or shock physics calculations where interface boundaries are represented only as discrete statistical approximations. In this work, we introduce new methods for generating Lagrangian computational meshes from Eulerian-based data. We focus specifically on shock physics problems that are relevant to ASC codes such as CTH and Alegra. New procedures for generating all-hexahedral finite element meshes from volume fraction data are introduced. A new primal-contouring approach is introduced for defining a geometric domain. New methods for refinement, node smoothing, resolving non-manifold conditions and defining geometry are also introduced as well as an extension of the algorithm to handle tetrahedral meshes. We also describe new scalable MPI-based implementations of these procedures. We describe a new software module, Sculptor, which has been developed for use as an embedded component of CTH. We also describe its interface and its use within the mesh generation code, CUBIT. Several examples are shown to illustrate the capabilities of Sculptor.

  10. Detecting Translation Errors in CAD Surfaces and Preparing Geometries for Mesh Generation

    SciTech Connect (OSTI)

    Petersson, N Anders; Chand, K K

    2001-08-27

    The authors have developed tools for the efficient preparation of CAD geometries for mesh generation. Geometries are read from IGES files and then maintained in a boundary-representation consisting of a patchwork of trimmed and untrimmed surfaces. Gross errors in the geometry can be identified and removed automatically while a user interface is provided for manipulating the geometry (such as correcting invalid trimming curves or removing unwanted details). Modifying the geometry by adding or deleting surfaces and/or sectioning it by arbitrary planes (e.g. symmetry planes) is also supported. These tools are used for robust and accurate geometry models for initial mesh generation and will be applied to in situ mesh generation requirements of moving and adaptive grid simulations.

  11. Mesh Generation for SHARP: Unprecedented Complexity | Department of Energy

    Office of Energy Efficiency and Renewable Energy (EERE) (indexed site)

    Mesh Generation for SHARP: Unprecedented Complexity Mesh Generation for SHARP: Unprecedented Complexity January 29, 2013 - 1:36pm Addthis SHARP Supporting Elements During this quarter, the framework team was involved in two primary efforts, mesh generation and implementation of a MOAB-based coupled multi-physics simulation. For mesh generation, finishing touches were put on three major, high-complexity hexahedral meshes, and support was provided for their use in various simulations: MATiS-H, an

  12. Petroleum Refining (2010 MECS) | Department of Energy

    Office of Energy Efficiency and Renewable Energy (EERE) (indexed site)

    Petroleum Refining (2010 MECS) Petroleum Refining (2010 MECS) Manufacturing Energy and Carbon Footprint for Petroleum Refining Sector (NAICS 324110) Energy use data source: 2010 EIA MECS (with adjustments) Footprint Last Revised: February 2014 View footprints for other sectors here. Manufacturing Energy and Carbon Footprint Petroleum Refining (125.36 KB) More Documents & Publications MECS 2006 - Petroleum Refining Cement (2010 MECS) Forest Products (2010 MECS) Manufacturing Energy Sankey

  13. GRAIN REFINEMENT OF URANIUM BILLETS

    DOE Patents [OSTI]

    Lewis, L.

    1964-02-25

    A method of refining the grain structure of massive uranium billets without resort to forging is described. The method consists in the steps of beta- quenching the billets, annealing the quenched billets in the upper alpha temperature range, and extrusion upset of the billets to an extent sufficient to increase the cross sectional area by at least 5 per cent. (AEC)

  14. Method for refining contaminated iridium

    DOE Patents [OSTI]

    Heshmatpour, B.; Heestand, R.L.

    1982-08-31

    Contaminated iridium is refined by alloying it with an alloying agent selected from the group consisting of manganese and an alloy of manganese and copper, and then dissolving the alloying agent from the formed alloy to provide a purified iridium powder.

  15. The generation of hexahedral meshes for assembly geometries: A survey

    SciTech Connect (OSTI)

    TAUTGES,TIMOTHY J.

    2000-02-14

    The finite element method is being used today to model component assemblies in a wide variety of application areas, including structural mechanics, fluid simulations, and others. Generating hexahedral meshes for these assemblies usually requires the use of geometry decomposition, with different meshing algorithms applied to different regions. While the primary motivation for this approach remains the lack of an automatic, reliable all-hexahedral meshing algorithm, requirements in mesh quality and mesh configuration for typical analyses are also factors. For these reasons, this approach is also sometimes required when producing other types of unstructured meshes. This paper will review progress to date in automating many parts of the hex meshing process, which has halved the time to produce all-hex meshes for large assemblies. Particular issues which have been exposed due to this progress will also be discussed, along with their applicability to the general unstructured meshing problem.

  16. Reformulated Gasoline Market Affected Refiners Differently, 1995

    Reports and Publications

    1996-01-01

    This article focuses on the costs of producing reformulated gasoline (RFG) as experienced by different types of refiners and on how these refiners fared this past summer, given the prices for RFG at the refinery gate.

  17. CUBIT mesh generation environment. Volume 1: Users manual

    SciTech Connect (OSTI)

    Blacker, T.D.; Bohnhoff, W.J.; Edwards, T.L.

    1994-05-01

    The CUBIT mesh generation environment is a two- and three-dimensional finite element mesh generation tool which is being developed to pursue the goal of robust and unattended mesh generation--effectively automating the generation of quadrilateral and hexahedral elements. It is a solid-modeler based preprocessor that meshes volume and surface solid models for finite element analysis. A combination of techniques including paving, mapping, sweeping, and various other algorithms being developed are available for discretizing the geometry into a finite element mesh. CUBIT also features boundary layer meshing specifically designed for fluid flow problems. Boundary conditions can be applied to the mesh through the geometry and appropriate files for analysis generated. CUBIT is specifically designed to reduce the time required to create all-quadrilateral and all-hexahedral meshes. This manual is designed to serve as a reference and guide to creating finite element models in the CUBIT environment.

  18. On combining Laplacian and optimization-based mesh smoothing techniques

    SciTech Connect (OSTI)

    Freitag, L.A.

    1997-07-01

    Local mesh smoothing algorithms have been shown to be effective in repairing distorted elements in automatically generated meshes. The simplest such algorithm is Laplacian smoothing, which moves grid points to the geometric center of incident vertices. Unfortunately, this method operates heuristically and can create invalid meshes or elements of worse quality than those contained in the original mesh. In contrast, optimization-based methods are designed to maximize some measure of mesh quality and are very effective at eliminating extremal angles in the mesh. These improvements come at a higher computational cost, however. In this article the author proposes three smoothing techniques that combine a smart variant of Laplacian smoothing with an optimization-based approach. Several numerical experiments are performed that compare the mesh quality and computational cost for each of the methods in two and three dimensions. The author finds that the combined approaches are very cost effective and yield high-quality meshes.

  19. Firing of pulverized solvent refined coal

    DOE Patents [OSTI]

    Derbidge, T. Craig; Mulholland, James A.; Foster, Edward P.

    1986-01-01

    An air-purged burner for the firing of pulverized solvent refined coal is constructed and operated such that the solvent refined coal can be fired without the coking thereof on the burner components. The air-purged burner is designed for the firing of pulverized solvent refined coal in a tangentially fired boiler.

  20. The Uranium Processing Facility (UPF) Finite Element Meshing Discussion

    Energy.gov [DOE]

    The Uranium Processing Facility (UPF) Finite Element Meshing Discussion Loring Wyllie Arne Halterman Degenkolb Engineers, San Francisco

  1. Cubit Mesh Generation Toolkit V11.1

    Energy Science and Technology Software Center (OSTI)

    2009-03-25

    CUBIT prepares models to be used in computer-based simulation of real-world events. CUBIT is a full-featured software toolkit for robust generation of two- and three-dimensional finite element meshes (grids) and geometry preparation. Its main goal is to reduce the time to generate meshes, particularly large hex meshes of complicated, interlocking assemblies.

  2. Automatic meshing of curved three-dimensional domains: Curving finite elements and curvature-based mesh control

    SciTech Connect (OSTI)

    Shephard, M.S.; Dey, S.; Georges, M.K.

    1995-12-31

    Specific issues associated with the automatic generation of finite element meshes for curved geometric domains axe considered. A review of the definition of when a triangulation is a valid mesh, a geometric triangulation, for curved geometric domains is given. Consideration is then given to the additional operations necessary to maintain the validity of a mesh when curved finite elements are employed. A procedure to control the mesh gradations based on the curvature of the geometric model faces is also given.

  3. ITP Petroleum Refining: Energy and Environmental Profile of the...

    Office of Energy Efficiency and Renewable Energy (EERE) (indexed site)

    and Environmental Profile of the U.S. Petroleum Refining Industry (November 2007) ITP Petroleum Refining: Energy and Environmental Profile of the U.S. Petroleum Refining Industry ...

  4. Diffusive mesh relaxation in ALE finite element numerical simulations

    SciTech Connect (OSTI)

    Dube, E.I.

    1996-06-01

    The theory for a diffusive mesh relaxation algorithm is developed for use in three-dimensional Arbitary Lagrange/Eulerian (ALE) finite element simulation techniques. This mesh relaxer is derived by a variational principle for an unstructured 3D grid using finite elements, and incorporates hourglass controls in the numerical implementation. The diffusive coefficients are based on the geometric properties of the existing mesh, and are chosen so as to allow for a smooth grid that retains the general shape of the original mesh. The diffusive mesh relaxation algorithm is then applied to an ALE code system, and results from several test cases are discussed.

  5. Vertical-Axis Wind Turbine Mesh Generator

    SciTech Connect (OSTI)

    2014-01-24

    VAWTGen is a mesh generator for creating a finite element beam mesh of arbitrary vertical-axis wind turbines (VAWT). The software accepts input files specifying tower and blade structural and aerodynamic descriptions and constructs a VAWT using a minimal set of inputs. VAWTs with an arbitrary number of blades can be constructed with or without a central tower. Strut connections between the tower and blades can be specified in an arbitrary manner. The software also facilitates specifying arbitrary joints between structural components and concentrated structural tenns (mass and stiffness). The output files which describe the VAWT configuration are intended to be used with the Offshore Wind ENergy Simulation (OWENS) Toolkit software for structural dynamics analysis of VAWTs. Furthermore, VAWTGen is useful for visualizing output from the OWENS analysis software.

  6. Vertical-Axis Wind Turbine Mesh Generator

    Energy Science and Technology Software Center (OSTI)

    2014-01-24

    VAWTGen is a mesh generator for creating a finite element beam mesh of arbitrary vertical-axis wind turbines (VAWT). The software accepts input files specifying tower and blade structural and aerodynamic descriptions and constructs a VAWT using a minimal set of inputs. VAWTs with an arbitrary number of blades can be constructed with or without a central tower. Strut connections between the tower and blades can be specified in an arbitrary manner. The software also facilitatesmore » specifying arbitrary joints between structural components and concentrated structural tenns (mass and stiffness). The output files which describe the VAWT configuration are intended to be used with the Offshore Wind ENergy Simulation (OWENS) Toolkit software for structural dynamics analysis of VAWTs. Furthermore, VAWTGen is useful for visualizing output from the OWENS analysis software.« less

  7. INGRID; 3-D Mesh Generation Nonlinear Systems

    SciTech Connect (OSTI)

    Stillman, D.W.; Rainsberger, R.

    1985-07-01

    INGRID is a general-purpose, three-dimensional mesh generator developed for use with finite element, nonlinear, structural dynamics codes. INGRID generates the large and complex input data files for DYNA3D, NIKE3D, FACET, and TOPAZ3D. One of the greatest advantages of INGRID is that virtually any shape can be described without resorting to wedge elements, tetrahedrons, triangular elements or highly distorted quadrilateral or hexahedral elements. Other capabilities available are in the areas of geometry and graphics. Exact surface equations and surface intersections considerably improve the ability to deal with accurate models, and a hidden line graphics algorithm is included which is efficient on the most complicated meshes. The primary new capability is associated with the boundary conditions, loads, and material properties required by nonlinear mechanics programs. Commands have been designed for each case to minimize user effort. This is particularly important since special processing is almost always required for each load or boundary condition.

  8. INGRID. 3-D Mesh Generation Nonlinear Systems

    SciTech Connect (OSTI)

    Christon, M.A.; Dovey, D.; Stillman, D.W.; Hallquist, J.O.; Rainsberger, R.B.

    1992-09-01

    INGRID is a general-purpose, three-dimensional mesh generator developed for use with finite element, nonlinear, structural dynamics codes. INGRID generates the large and complex input data files for DYNA3D, NIKE3D, FACET, and TOPAZ3D. One of the greatest advantages of INGRID is that virtually any shape can be described without resorting to wedge elements, tetrahedrons, triangular elements or highly distorted quadrilateral or hexahedral elements. Other capabilities available are in the areas of geometry and graphics. Exact surface equations and surface intersections considerably improve the ability to deal with accurate models, and a hidden line graphics algorithm is included which is efficient on the most complicated meshes. The primary new capability is associated with the boundary conditions, loads, and material properties required by nonlinear mechanics programs. Commands have been designed for each case to minimize user effort. This is particularly important since special processing is almost always required for each load or boundary condition.

  9. INGRID. 3-D Mesh Generation Nonlinear Systems

    SciTech Connect (OSTI)

    Stillman, D.W.; Rainsberger, R.

    1985-07-01

    INGRID is a general-purpose, three-dimensional mesh generator developed for use with finite element, nonlinear, structural dynamics codes. INGRID generates the large and complex input data files for DYNA3D, NIKE3D, FACET, and TOPAZ3D (ESTSC. One of the greatest advantages of INGRID is that virtually any shape can be described without resorting to wedge elements, tetrahedrons, triangular elements or highly distorted quadrilateral or hexahedral elements. Other capabilities available are in the areas of geometry and graphics. Exact surface equations and surface intersections considerably improve the ability to deal with accurate models, and a hidden line graphics algorithm is included which is efficient on the most complicated meshes. The primary new capability is associated with the boundary conditions, loads, and material properties required by nonlinear mechanics programs. Commands have been designed for each case to minimize user effort. This is particularly important since special processing is almost always required for each load or boundary condition.

  10. INGRID. 3-D Mesh Generation Nonlinear Systems

    SciTech Connect (OSTI)

    Stillman, D.W.; Rainsberger, R.

    1985-07-01

    INGRID is a general-purpose, three-dimensional mesh generator developed for use with finite element, nonlinear, structural dynamics codes. INGRID generates the large and complex input data files for DYNA3D, NIKE3D, FACET, and TOPAZ3D. One of the greatest advantages of INGRID is that virtually any shape can be described without resorting to wedge elements, tetrahedrons, triangular elements or highly distorted quadrilateral or hexahedral elements. Other capabilities available are in the areas of geometry and graphics. Exact surface equations and surface intersections considerably improve the ability to deal with accurate models, and a hidden line graphics algorithm is included which is efficient on the most complicated meshes. The primary new capability is associated with the boundary conditions, loads, and material properties required by nonlinear mechanics programs. Commands have been designed for each case to minimize user effort. This is particularly important since special processing is almost always required for each load or boundary condition.

  11. 3-D Mesh Generation Nonlinear Systems

    SciTech Connect (OSTI)

    1994-04-07

    INGRID is a general-purpose, three-dimensional mesh generator developed for use with finite element, nonlinear, structural dynamics codes. INGRID generates the large and complex input data files for DYNA3D, NIKE3D, FACET, and TOPAZ3D. One of the greatest advantages of INGRID is that virtually any shape can be described without resorting to wedge elements, tetrahedrons, triangular elements or highly distorted quadrilateral or hexahedral elements. Other capabilities available are in the areas of geometry and graphics. Exact surface equations and surface intersections considerably improve the ability to deal with accurate models, and a hidden line graphics algorithm is included which is efficient on the most complicated meshes. The primary new capability is associated with the boundary conditions, loads, and material properties required by nonlinear mechanics programs. Commands have been designed for each case to minimize user effort. This is particularly important since special processing is almost always required for each load or boundary condition.

  12. Wireless experiments on a Motorola mesh testbed.

    SciTech Connect (OSTI)

    Riblett, Loren E., Jr.; Wiseman, James M.; Witzke, Edward L.

    2010-06-01

    Motomesh is a Motorola product that performs mesh networking at both the client and access point levels and allows broadband mobile data connections with or between clients moving at vehicular speeds. Sandia National aboratories has extensive experience with this product and its predecessors in infrastructure-less mobile environments. This report documents experiments, which characterize certain aspects of how the Motomesh network performs when obile units are added to a fixed network infrastructure.

  13. Data-Parallel Mesh Connected Components Labeling and Analysis

    SciTech Connect (OSTI)

    Harrison, Cyrus; Childs, Hank; Gaither, Kelly

    2011-04-10

    We present a data-parallel algorithm for identifying and labeling the connected sub-meshes within a domain-decomposed 3D mesh. The identification task is challenging in a distributed-memory parallel setting because connectivity is transitive and the cells composing each sub-mesh may span many or all processors. Our algorithm employs a multi-stage application of the Union-find algorithm and a spatial partitioning scheme to efficiently merge information across processors and produce a global labeling of connected sub-meshes. Marking each vertex with its corresponding sub-mesh label allows us to isolate mesh features based on topology, enabling new analysis capabilities. We briefly discuss two specific applications of the algorithm and present results from a weak scaling study. We demonstrate the algorithm at concurrency levels up to 2197 cores and analyze meshes containing up to 68 billion cells.

  14. An h-adaptive finite element method for turbulent heat transfer

    SciTech Connect (OSTI)

    Carriington, David B [Los Alamos National Laboratory

    2009-01-01

    A two-equation turbulence closure model (k-{omega}) using an h-adaptive grid technique and finite element method (FEM) has been developed to simulate low Mach flow and heat transfer. These flows are applicable to many flows in engineering and environmental sciences. Of particular interest in the engineering modeling areas are: combustion, solidification, and heat exchanger design. Flows for indoor air quality modeling and atmospheric pollution transport are typical types of environmental flows modeled with this method. The numerical method is based on a hybrid finite element model using an equal-order projection process. The model includes thermal and species transport, localized mesh refinement (h-adaptive) and Petrov-Galerkin weighting for the stabilizing the advection. This work develops the continuum model of a two-equation turbulence closure method. The fractional step solution method is stated along with the h-adaptive grid method (Carrington and Pepper, 2002). Solutions are presented for 2d flow over a backward-facing step.

  15. Integration of Mesh Optimization with 3D All-Hex Mesh Generation, LDRD Subcase 3504340000, Final Report

    SciTech Connect (OSTI)

    KNUPP,PATRICK; MITCHELL,SCOTT A.

    1999-11-01

    In an attempt to automatically produce high-quality all-hex meshes, we investigated a mesh improvement strategy: given an initial poor-quality all-hex mesh, we iteratively changed the element connectivity, adding and deleting elements and nodes, and optimized the node positions. We found a set of hex reconnection primitives. We improved the optimization algorithms so they can untangle a negative-Jacobian mesh, even considering Jacobians on the boundary, and subsequently optimize the condition number of elements in an untangled mesh. However, even after applying both the primitives and optimization we were unable to produce high-quality meshes in certain regions. Our experiences suggest that many boundary configurations of quadrilaterals admit no hexahedral mesh with positive Jacobians, although we have no proof of this.

  16. A characterization of the quadrilateral meshes of a surface which admit a compatible hexahedral mesh of the enclosed volume

    SciTech Connect (OSTI)

    Mitchell, S.A.

    1995-09-01

    A popular three-dimensional mesh generation scheme is to start with a quadrilateral of the surface of a volume, and then attempt to fill the interior of volume with hexahedra, so that the hexahedra touch the surface in exactly the given quadrilaterals. Folklore has maintained that there are many quadrilateral meshes for which no such compatible hexahedral mesh exists. In this paper we give an existence proof which contradicts this folklore: A quadrilateral mesh need only satisfy some very weak conditions for there to exist a compatible hexahedral mesh. For a volume that is topologically a ball, any quadrilateral mesh composed of an even number of quadrilaterals admits a compatible hexahedral mesh. We extend this to volumes of higher genus: There is a construction to reduce to the ball case if and only if certain cycles of edges are even.

  17. Improving the accuracy of macromolecular structure refinement

    U.S. Department of Energy (DOE) all webpages (Extended Search)

    is challenging at low resolution. We compared refinement methods using synchrotron diffraction data of photosystem I at 7.4 resolution, starting from different initial models...

  18. Refiners Increasingly Employing Catalyst Regeneration as Alternative...

    Open Energy Information (Open El) [EERE & EIA]

    million by the end of 2019. Refiners Benefit from Catalyst Regeneration Technology via Price Reductions and Lower Maintenance Costs The catalyst regeneration technology is the...

  19. Right rock: Finding/refining customer expectations

    SciTech Connect (OSTI)

    Ashby, R.

    1997-11-01

    This report contains viewgraphs on methods of finding customer expectations of software and then refining the documentation and software to fit these expectations.

  20. MeSh ToolKit v1.2

    Energy Science and Technology Software Center (OSTI)

    2004-05-15

    MSTK or Mesh Toolkit is a mesh framework that allows users to represent, manipulate and query unstructured 3D arbitrary topology meshes in a general manner without the need to code their own data structures. MSTK is a flexible framework in that is allows (or will eventually allow) a wide variety of underlying representations for the mesh while maintaining a common interface. It will allow users to choose from different mesh representations either at initialization ormore » during the program execution so that the optimal data structures are used for the particular algorithm. The interaction of users and applications with MSTK is through a functional interface that acts as through the mesh always contains vertices, edges, faces and regions and maintains connectivity between all these entities.« less

  1. Hexahedral mesh generation via the dual arrangement of surfaces

    SciTech Connect (OSTI)

    Mitchell, S.A.; Tautges, T.J.

    1997-12-31

    Given a general three-dimensional geometry with a prescribed quadrilateral surface mesh, the authors consider the problem of constructing a hexahedral mesh of the geometry whose boundary is exactly the prescribed surface mesh. Due to the specialized topology of hexahedra, this problem is more difficult than the analogous one for tetrahedra. Folklore has maintained that a surface mesh must have a constrained structure in order for there to exist a compatible hexahedral mesh. However, they have proof that a surface mesh need only satisfy mild parity conditions, depending on the topology of the three-dimensional geometry, for there to exist a compatible hexahedral mesh. The proof is based on the realization that a hexahedral mesh is dual to an arrangement of surfaces, and the quadrilateral surface mesh is dual to the arrangement of curves bounding these surfaces. The proof is constructive and they are currently developing an algorithm called Whisker Weaving (WW) that mirrors the proof steps. Given the bounding curves, WW builds the topological structure of an arrangement of surfaces having those curves as its boundary. WW progresses in an advancing front manner. Certain local rules are applied to avoid structures that lead to poor mesh quality. Also, after the arrangement is constructed, additional surfaces are inserted to separate features, so e.g., no two hexahedra share more than one quadrilateral face. The algorithm has generated meshes for certain non-trivial problems, but is currently unreliable. The authors are exploring strategies for consistently selecting which portion of the surface arrangement to advance based on the existence proof. This should lead us to a robust algorithm for arbitrary geometries and surface meshes.

  2. Pneumatic conveying of pulverized solvent refined coal

    DOE Patents [OSTI]

    Lennon, Dennis R.

    1984-11-06

    A method for pneumatically conveying solvent refined coal to a burner under conditions of dilute phase pneumatic flow so as to prevent saltation of the solvent refined coal in the transport line by maintaining the transport fluid velocity above approximately 95 ft/sec.

  3. Introducing the Target-Matrix Paradigm for Mesh Optimization...

    Office of Scientific and Technical Information (OSTI)

    Title: Introducing the Target-Matrix Paradigm for Mesh Optimization via Node-movement. Abstract not provided. Authors: Knupp, Patrick Michael Publication Date: 2010-10-01 OSTI ...

  4. AN ALGORITHM FOR PARALLEL SN SWEEPS ON UNSTRUCTURED MESHES

    SciTech Connect (OSTI)

    S. D. PAUTZ

    2000-12-01

    We develop a new algorithm for performing parallel S{sub n} sweeps on unstructured meshes. The algorithm uses a low-complexity list ordering heuristic to determine a sweep ordering on any partitioned mesh. For typical problems and with ''normal'' mesh partitionings we have observed nearly linear speedups on up to 126 processors. This is an important and desirable result, since although analyses of structured meshes indicate that parallel sweeps will not scale with normal partitioning approaches, we do not observe any severe asymptotic degradation in the parallel efficiency with modest ({le}100) levels of parallelism. This work is a fundamental step in the development of parallel S{sub n} methods.

  5. Incorporating the min-max mesh optimization method within the...

    Office of Scientific and Technical Information (OSTI)

    Incorporating the min-max mesh optimization method within the Target-Matrix Paradigm. ... Country of Publication: United States Language: English Word Cloud More Like This Full ...

  6. Incorporating the min-max mesh optimization method within the...

    Office of Scientific and Technical Information (OSTI)

    Title: Incorporating the min-max mesh optimization method within the Target-Matrix ... Country of Publication: United States Language: English Word Cloud More Like This Full ...

  7. The Uranium Processing Facility Finite Element Meshing Discussion

    Office of Environmental Management (EM)

    Uranium Processing Facility (UPF) Finite Element Meshing Discussion ...Need picture of Building... October 25, 2011 Department of Energy - Natural Phenomenon Hazard Workshop 1 ...

  8. Hexahedral finite element mesh coarsening using pillowing technique

    DOE Patents [OSTI]

    Staten, Matthew L.; Woodbury, Adam C.; Benzley, Steven E.; Shepherd, Jason F.

    2012-06-05

    A techniques for coarsening a hexahedral mesh is described. The technique includes identifying a coarsening region within a hexahedral mesh to be coarsened. A boundary sheet of hexahedral elements is inserted into the hexahedral mesh around the coarsening region. A column of hexahedral elements is identified within the boundary sheet. The column of hexahedral elements is collapsed to create an extraction sheet of hexahedral elements contained within the coarsening region. Then, the extraction sheet of hexahedral elements is extracted to coarsen the hexahedral mesh.

  9. 3-D Mesh Generation Nonlinear Systems

    Energy Science and Technology Software Center (OSTI)

    1994-04-07

    INGRID is a general-purpose, three-dimensional mesh generator developed for use with finite element, nonlinear, structural dynamics codes. INGRID generates the large and complex input data files for DYNA3D, NIKE3D, FACET, and TOPAZ3D. One of the greatest advantages of INGRID is that virtually any shape can be described without resorting to wedge elements, tetrahedrons, triangular elements or highly distorted quadrilateral or hexahedral elements. Other capabilities available are in the areas of geometry and graphics. Exact surfacemore » equations and surface intersections considerably improve the ability to deal with accurate models, and a hidden line graphics algorithm is included which is efficient on the most complicated meshes. The primary new capability is associated with the boundary conditions, loads, and material properties required by nonlinear mechanics programs. Commands have been designed for each case to minimize user effort. This is particularly important since special processing is almost always required for each load or boundary condition.« less

  10. North Dakota Refining Capacity Study

    SciTech Connect (OSTI)

    Dennis Hill; Kurt Swenson; Carl Tuura; Jim Simon; Robert Vermette; Gilberto Marcha; Steve Kelly; David Wells; Ed Palmer; Kuo Yu; Tram Nguyen; Juliam Migliavacca

    2011-01-05

    According to a 2008 report issued by the United States Geological Survey, North Dakota and Montana have an estimated 3.0 to 4.3 billion barrels of undiscovered, technically recoverable oil in an area known as the Bakken Formation. With the size and remoteness of the discovery, the question became 'can a business case be made for increasing refining capacity in North Dakota?' And, if so what is the impact to existing players in the region. To answer the question, a study committee comprised of leaders in the region's petroleum industry were brought together to define the scope of the study, hire a consulting firm and oversee the study. The study committee met frequently to provide input on the findings and modify the course of the study, as needed. The study concluded that the Petroleum Area Defense District II (PADD II) has an oversupply of gasoline. With that in mind, a niche market, naphtha, was identified. Naphtha is used as a diluent used for pipelining the bitumen (heavy crude) from Canada to crude markets. The study predicted there will continue to be an increase in the demand for naphtha through 2030. The study estimated the optimal configuration for the refinery at 34,000 barrels per day (BPD) producing 15,000 BPD of naphtha and a 52 percent refinery charge for jet and diesel yield. The financial modeling assumed the sponsor of a refinery would invest its own capital to pay for construction costs. With this assumption, the internal rate of return is 9.2 percent which is not sufficient to attract traditional investment given the risk factor of the project. With that in mind, those interested in pursuing this niche market will need to identify incentives to improve the rate of return.

  11. A Lagrangian-Eulerian method with zoomable hidden fine-mesh approach to solving advection-dispersion equations

    SciTech Connect (OSTI)

    Yeh, G.T. )

    1990-06-01

    A Lagrangian-Eulerian method with zoomable hidden fine-mesh approach (LEZOOM), that can be adapted with either finite element or finite difference methods, is used to solve the advection-dispersion equation. The approach is based on automatic adaptation of zooming a hidden fine mesh in regions where the sharp front is located. Application of LEZOOM to four bench mark problems indicates that it can handle the advection-dispersion/diffusion problems with mesh Peclet numbers ranged from 0 to {infinity} and with mesh Courant numbers well in excess of 1. Difficulties that can be resolved with LEZOOM include numerical dispersion, oscillations, the clipping of peaks, and the effect of grid orientation. Nonuniform grid as well as spatial temporally variable flow pose no problems with LEZOOM. Both initial and boundary value problems can be solved accurately with LEZOOM. It is shown that although the mixed Lagrangian-Eulerian (LE) approach (LEZOOM without zooming) also produces excessive numerical dispersion as the upstream finite element (UFE) method, the LE approach is superior to the UFE method.

  12. MeshVoro: A Three-Dimensional Voronoi Mesh Building Tool for the TOUGH Family of Codes

    SciTech Connect (OSTI)

    Freeman, C. M.; Boyle, K. L.; Reagan, M.; Johnson, J.; Rycroft, C.; Moridis, G. J.

    2013-09-30

    Few tools exist for creating and visualizing complex three-dimensional simulation meshes, and these have limitations that restrict their application to particular geometries and circumstances. Mesh generation needs to trend toward ever more general applications. To that end, we have developed MeshVoro, a tool that is based on the Voro (Rycroft 2009) library and is capable of generating complex threedimensional Voronoi tessellation-based (unstructured) meshes for the solution of problems of flow and transport in subsurface geologic media that are addressed by the TOUGH (Pruess et al. 1999) family of codes. MeshVoro, which includes built-in data visualization routines, is a particularly useful tool because it extends the applicability of the TOUGH family of codes by enabling the scientifically robust and relatively easy discretization of systems with challenging 3D geometries. We describe several applications of MeshVoro. We illustrate the ability of the tool to straightforwardly transform a complex geological grid into a simulation mesh that conforms to the specifications of the TOUGH family of codes. We demonstrate how MeshVoro can describe complex system geometries with a relatively small number of grid blocks, and we construct meshes for geometries that would have been practically intractable with a standard Cartesian grid approach. We also discuss the limitations and appropriate applications of this new technology.

  13. Firing of pulverized solvent refined coal

    DOE Patents [OSTI]

    Lennon, Dennis R.; Snedden, Richard B.; Foster, Edward P.; Bellas, George T.

    1990-05-15

    A burner for the firing of pulverized solvent refined coal is constructed and operated such that the solvent refined coal can be fired successfully without any performance limitations and without the coking of the solvent refined coal on the burner components. The burner is provided with a tangential inlet of primary air and pulverized fuel, a vaned diffusion swirler for the mixture of primary air and fuel, a center water-cooled conical diffuser shielding the incoming fuel from the heat radiation from the flame and deflecting the primary air and fuel steam into the secondary air, and a watercooled annulus located between the primary air and secondary air flows.

  14. Volume Decomposition and Feature Recognition for Hexahedral Mesh Generation

    SciTech Connect (OSTI)

    GADH,RAJIT; LU,YONG; TAUTGES,TIMOTHY J.

    1999-09-27

    Considerable progress has been made on automatic hexahedral mesh generation in recent years. Several automatic meshing algorithms have proven to be very reliable on certain classes of geometry. While it is always worth pursuing general algorithms viable on more general geometry, a combination of the well-established algorithms is ready to take on classes of complicated geometry. By partitioning the entire geometry into meshable pieces matched with appropriate meshing algorithm the original geometry becomes meshable and may achieve better mesh quality. Each meshable portion is recognized as a meshing feature. This paper, which is a part of the feature based meshing methodology, presents the work on shape recognition and volume decomposition to automatically decompose a CAD model into meshable volumes. There are four phases in this approach: (1) Feature Determination to extinct decomposition features, (2) Cutting Surfaces Generation to form the ''tailored'' cutting surfaces, (3) Body Decomposition to get the imprinted volumes; and (4) Meshing Algorithm Assignment to match volumes decomposed with appropriate meshing algorithms. The feature determination procedure is based on the CLoop feature recognition algorithm that is extended to be more general. Results are demonstrated over several parts with complicated topology and geometry.

  15. U.S. Refining Capacity Utilization

    Reports and Publications

    1995-01-01

    This article briefly reviews recent trends in domestic refining capacity utilization and examines in detail the differences in reported crude oil distillation capacities and utilization rates among different classes of refineries.

  16. Hydrogen Piping Experience in Chevron Refining

    Office of Energy Efficiency and Renewable Energy (EERE) (indexed site)

    Piping Experience in Chevron Refining Ned Niccolls Materials Engineer Chevron Energy Technology Company Hydrogen Pipeline Working Group Workshop August 30-31, 2005 Outline 2 Overall perspectives from long term use of hydrogen piping in refining. Piping specifications and practices. The (few) problem areas. Related industry work: American Petroleum Institute corrosion and materials work on high temperature hydrogen attack. Overall Perspectives 3 Few problems with hydrogen piping operating at

  17. Refining Bio-Oil alongside Petroleum | Department of Energy

    Office of Energy Efficiency and Renewable Energy (EERE) (indexed site)

    Refining Bio-Oil alongside Petroleum Refining Bio-Oil alongside Petroleum April 9, 2013 - 12:00am Addthis W.R. Grace, a leading provider of refining technologies, and Pacific ...

  18. Source: Energy Information Administration, Form EIA-782A, "Refiners...

    U.S. Energy Information Administration (EIA) (indexed site)

    Motor Gasoline No. 2 Distillate Residual Fuel Oil 5. U.S. Refiner Wholesale Petroleum Product Volumes Figure Percentages of Refiner Wholesale Volumes 1995 Annual Averages Motor...

  19. Source: Energy Information Administration, Form EIA-782A, "Refiners...

    U.S. Energy Information Administration (EIA) (indexed site)

    Day Motor Gasoline No. 2 Distillate Residual Fuel Oil 3. U.S. Refiner Retail Petroleum Product Volumes Figure Percentages of Refiner Retail Volumes 1997 Annual Averages Motor...

  20. Source: Energy Information Administration, Form EIA-782A, "Refiners...

    U.S. Energy Information Administration (EIA) (indexed site)

    Motor Gasoline No. 2 Distillate Residual Fuel Oil 5. U.S. Refiner Wholesale Petroleum Product Volumes Figure Percentages of Refiner Wholesale Volumes 1997 Annual Averages Motor...

  1. Source: Energy Information Administration, Form EIA-782A, "Refiners...

    U.S. Energy Information Administration (EIA) (indexed site)

    Day Motor Gasoline No. 2 Distillate Residual Fuel Oil 3. U.S. Refiner Retail Petroleum Product Volumes Figure Percentages of Refiner Retail Volumes 1995 Annual Averages Motor...

  2. Source: Energy Information Administration, Form EIA-782A, "Refiners...

    U.S. Energy Information Administration (EIA) (indexed site)

    Day Motor Gasoline No. 2 Distillate Residual Fuel Oil 3. U.S. Refiner Retail Petroleum Product Volumes Figure Percentages of Refiner Retail Volumes 1996 Annual Averages Motor...

  3. Source: Energy Information Administration, Form EIA-782A, "Refiners...

    U.S. Energy Information Administration (EIA) (indexed site)

    Motor Gasoline No. 2 Distillate Residual Fuel Oil 5. U.S. Refiner Wholesale Petroleum Product Volumes Figure Percentages of Refiner Wholesale Volumes 1996 Annual Averages Motor...

  4. ,"Aviation Gasoline Sales to End Users Refiner Sales Volumes...

    U.S. Energy Information Administration (EIA) (indexed site)

    Aviation Gasoline Sales to End Users Refiner Sales Volumes" ,"Click worksheet name or tab ... Data for" ,"Data 1","Aviation Gasoline Sales to End Users Refiner ...

  5. ,"U.S. Motor Gasoline Refiner Sales Volumes"

    U.S. Energy Information Administration (EIA) (indexed site)

    Data for" ,"Data 1","U.S. Motor Gasoline Refiner Sales ... AM" "Back to Contents","Data 1: U.S. Motor Gasoline Refiner Sales Volumes" ...

  6. ITP Petroleum Refining: Impacts of Condition Assessment on Energy...

    Office of Energy Efficiency and Renewable Energy (EERE) (indexed site)

    Impacts of Condition Assessment on Energy Use: Selected Applications in Chemicals Processing and Petroleum Refining ITP Petroleum Refining: Impacts of Condition Assessment on ...

  7. Method and apparatus for connecting finite element meshes and performing simulations therewith

    DOE Patents [OSTI]

    Dohrmann, Clark R.; Key, Samuel W.; Heinstein, Martin W.

    2003-05-06

    The present invention provides a method of connecting dissimilar finite element meshes. A first mesh, designated the master mesh, and a second mesh, designated the slave mesh, each have interface surfaces proximal the other. Each interface surface has a corresponding interface mesh comprising a plurality of interface nodes. Each slave interface node is assigned new coordinates locating the interface node on the interface surface of the master mesh. The slave interface surface is further redefined to be the projection of the slave interface mesh onto the master interface surface.

  8. Trends in petroleum refining process technology

    SciTech Connect (OSTI)

    Kowalczyk, D.

    1995-12-31

    In the 1990`s, the shift toward reformulated fuels and the unrelenting economic pressures on the petroleum refining industry have led to the ongoing development of a series of technological advances to improve fuels quality and industry operating efficiency. In this paper, ten of the most innovative and high impact recent developments in petroleum refining process technology will be highlighted. Process improvements and innovations have occurred in all facets of petroleum refining operations including fluid catalytic cracking, ether production, desulfurization, hydrocracking, gas processing, environmental control and heavy oil processing. Discussed will be the technical and economic impact of each of these new technologies on the petroleum refinery of the late 20th and early 21st century.

  9. JAPAN: Refining options and liberalization plans

    SciTech Connect (OSTI)

    Totto, L.; Isaak, D.T.

    1988-01-01

    The reformulation of Japan's petroleum import policy is important to Japan and to the international energy community. The technical and economic factors involved in opening the Japanese market is unknown. Assuming that foreign refiners have the technical capability to meet Japanese product specifications, the prices and volumes that will prove economical to both parties are also little known. Japanese refiners have been investigating the possibility of exporting gasoline and processing crude for China and Malaysia. The study demonstrates that under certain trade policies, Japan could become a significant product exporter. This study's purpose is to investigate the economic efficiency of alternative petroleum supply options, i.e., combining Japan's refining and product imports. An evaluation of the current import program and the technically feasible alternatives will play a major role in a new import policy. For this evaluation, a linear programming (LP) model of Japan's domestic refinery capacity and the petroleum import system was constructed. 3 figs., 23 tabs.

  10. Metal decontamination for waste minimization using liquid metal refining technology

    SciTech Connect (OSTI)

    Joyce, E.L. Jr.; Lally, B.; Ozturk, B.; Fruehan, R.J.

    1993-09-01

    The current Department of Energy Mixed Waste Treatment Project flowsheet indicates that no conventional technology, other than surface decontamination, exists for metal processing. Current Department of Energy guidelines require retrievable storage of all metallic wastes containing transuranic elements above a certain concentration. This project is in support of the National Mixed Low Level Waste Treatment Program. Because of the high cost of disposal, it is important to develop an effective decontamination and volume reduction method for low-level contaminated metals. It is important to be able to decontaminate complex shapes where surfaces are hidden or inaccessible to surface decontamination processes and destruction of organic contamination. These goals can be achieved by adapting commercial metal refining processes to handle radioactive and organic contaminated metal. The radioactive components are concentrated in the slag, which is subsequently vitrified; hazardous organics are destroyed by the intense heat of the bath. The metal, after having been melted and purified, could be recycled for use within the DOE complex. In this project, we evaluated current state-of-the-art technologies for metal refining, with special reference to the removal of radioactive contaminants and the destruction of hazardous organics. This evaluation was based on literature reports, industrial experience, plant visits, thermodynamic calculations, and engineering aspects of the various processes. The key issues addressed included radioactive partitioning between the metal and slag phases, minimization of secondary wastes, operability of the process subject to widely varying feed chemistry, and the ability to seal the candidate process to prevent the release of hazardous species.

  11. Analyte separation utilizing temperature programmed desorption of a preconcentrator mesh

    DOE Patents [OSTI]

    Linker, Kevin L.; Bouchier, Frank A.; Theisen, Lisa; Arakaki, Lester H.

    2007-11-27

    A method and system for controllably releasing contaminants from a contaminated porous metallic mesh by thermally desorbing and releasing a selected subset of contaminants from a contaminated mesh by rapidly raising the mesh to a pre-determined temperature step or plateau that has been chosen beforehand to preferentially desorb a particular chemical specie of interest, but not others. By providing a sufficiently long delay or dwell period in-between heating pulses, and by selecting the optimum plateau temperatures, then different contaminant species can be controllably released in well-defined batches at different times to a chemical detector in gaseous communication with the mesh. For some detectors, such as an Ion Mobility Spectrometer (IMS), separating different species in time before they enter the IMS allows the detector to have an enhanced selectivity.

  12. Finite element meshing approached as a global minimization process

    SciTech Connect (OSTI)

    WITKOWSKI,WALTER R.; JUNG,JOSEPH; DOHRMANN,CLARK R.; LEUNG,VITUS J.

    2000-03-01

    The ability to generate a suitable finite element mesh in an automatic fashion is becoming the key to being able to automate the entire engineering analysis process. However, placing an all-hexahedron mesh in a general three-dimensional body continues to be an elusive goal. The approach investigated in this research is fundamentally different from any other that is known of by the authors. A physical analogy viewpoint is used to formulate the actual meshing problem which constructs a global mathematical description of the problem. The analogy used was that of minimizing the electrical potential of a system charged particles within a charged domain. The particles in the presented analogy represent duals to mesh elements (i.e., quads or hexes). Particle movement is governed by a mathematical functional which accounts for inter-particles repulsive, attractive and alignment forces. This functional is minimized to find the optimal location and orientation of each particle. After the particles are connected a mesh can be easily resolved. The mathematical description for this problem is as easy to formulate in three-dimensions as it is in two- or one-dimensions. The meshing algorithm was developed within CoMeT. It can solve the two-dimensional meshing problem for convex and concave geometries in a purely automated fashion. Investigation of the robustness of the technique has shown a success rate of approximately 99% for the two-dimensional geometries tested. Run times to mesh a 100 element complex geometry were typically in the 10 minute range. Efficiency of the technique is still an issue that needs to be addressed. Performance is an issue that is critical for most engineers generating meshes. It was not for this project. The primary focus of this work was to investigate and evaluate a meshing algorithm/philosophy with efficiency issues being secondary. The algorithm was also extended to mesh three-dimensional geometries. Unfortunately, only simple geometries were tested

  13. The strategic outlook for petroleum refiners

    SciTech Connect (OSTI)

    Cobb, C.

    1994-12-31

    After several years of acceptable and relatively reliable profitability, refiners were plunged into uncertainty once again following passage of the Clean Air Act Amendments (CAAA) in 1990. While many of the original uncertainties that attended these regulations have since been resolved, the industry now must prepare for the new manufacturing, distributions, and transportation challenges that undoubtedly will accompany the first stages of reformulated gasoline (RFG) compliance in early 1995. This impending challenge introduces several fundamental questions: (1) How has the industry changed and adjusted to respond to anticipated future needs? (2) What strategies are refiners employing today? (3) What are industry performance expectations over the next several years?

  14. Using supercritical fluids to refine hydrocarbons

    DOE Patents [OSTI]

    Yarbro, Stephen Lee

    2015-06-09

    A system and method for reactively refining hydrocarbons, such as heavy oils with API gravities of less than 20 degrees and bitumen-like hydrocarbons with viscosities greater than 1000 cp at standard temperature and pressure, using a selected fluid at supercritical conditions. A reaction portion of the system and method delivers lightweight, volatile hydrocarbons to an associated contacting unit which operates in mixed subcritical/supercritical or supercritical modes. Using thermal diffusion, multiphase contact, or a momentum generating pressure gradient, the contacting unit separates the reaction products into portions that are viable for use or sale without further conventional refining and hydro-processing techniques.

  15. Optimization-based mesh correction with volume and convexity constraints

    DOE PAGES-Beta [OSTI]

    D'Elia, Marta; Ridzal, Denis; Peterson, Kara J.; Bochev, Pavel; Shashkov, Mikhail

    2016-02-24

    Here, we consider the problem of finding a mesh such that 1) it is the closest, with respect to a suitable metric, to a given source mesh having the same connectivity, and 2) the volumes of its cells match a set of prescribed positive values that are not necessarily equal to the cell volumes in the source mesh. Also, this volume correction problem arises in important simulation contexts, such as satisfying a discrete geometric conservation law and solving transport equations by incremental remapping or similar semi-Lagrangian transport schemes. In this paper we formulate volume correction as a constrained optimization problemmore » in which the distance to the source mesh defines an optimization objective, while the prescribed cell volumes, mesh validity and/or cell convexity specify the constraints. We solve this problem numerically using a sequential quadratic programming (SQP) method whose performance scales with the mesh size. To achieve scalable performance we develop a specialized multigrid-based preconditioner for optimality systems that arise in the application of the SQP method to the volume correction problem. Numerical examples illustrate the importance of volume correction, and showcase the accuracy, robustness and scalability of our approach.« less

  16. Feature based volume decomposition for automatic hexahedral mesh generation

    SciTech Connect (OSTI)

    LU,YONG; GADH,RAJIT; TAUTGES,TIMOTHY J.

    2000-02-21

    Much progress has been made through these years to achieve automatic hexahedral mesh generation. While general meshing algorithms that can take on general geometry are not there yet; many well-proven automatic meshing algorithms now work on certain classes of geometry. This paper presents a feature based volume decomposition approach for automatic Hexahedral Mesh generation. In this approach, feature recognition techniques are introduced to determine decomposition features from a CAD model. The features are then decomposed and mapped with appropriate automatic meshing algorithms suitable for the correspondent geometry. Thus a formerly unmeshable CAD model may become meshable. The procedure of feature decomposition is recursive: sub-models are further decomposed until either they are matched with appropriate meshing algorithms or no more decomposition features are detected. The feature recognition methods employed are convexity based and use topology and geometry information, which is generally available in BREP solid models. The operations of volume decomposition are also detailed in the paper. The final section, the capability of the feature decomposer is demonstrated over some complicated manufactured parts.

  17. ITP Petroleum Refining: Energy Efficiency Roadmap for Petroleum Refineries

    Office of Energy Efficiency and Renewable Energy (EERE) (indexed site)

    in California | Department of Energy Energy Efficiency Roadmap for Petroleum Refineries in California ITP Petroleum Refining: Energy Efficiency Roadmap for Petroleum Refineries in California refining_roadmap.pdf (1.34 MB) More Documents & Publications ITP Petroleum Refining: Profile of the Petroleum Refining Industry in California: California Industries of the Future Program ITP Petroleum Refining: Energy Efficiency Roadmap for Petroleum Refineries in California Bandwidth Study U.S.

  18. Energy Bandwidth for Petroleum Refining Processes

    SciTech Connect (OSTI)

    none,

    2006-10-01

    The petroleum refining energy bandwidth report analyzes the most energy-intensive unit operations used in U.S. refineries: crude oil distillation, fluid catalytic cracking, catalytic hydrotreating, catalytic reforming, and alkylation. The "bandwidth" provides a snapshot of the energy losses that can potentially be recovered through best practices and technology R&D.

  19. Focus on Venezuelan heavy crude: refining margins

    SciTech Connect (OSTI)

    Not Available

    1984-01-25

    Of six crudes refined in the US Gulf Coast, heavy Venezuelan crude Lagunillas (15/sup 0/ API) provides the best margin per barrel. Data for end of December 1983 and the first three weeks of January show that margins on all crudes are on the rise in this market, due to a turnaround in product prices. The lighter crudes are showing the greatest increase in Gross Product Worth. This is having a modest shrinking effect on the margin differential between light and heavy crudes in this market. The domestic crude West Texas Intermediate, at 40/sup 0/ API, provides the highest GPW in this crude slate sample, over US $31 per barrel, compared to GPW of under US $28 per barrel for Lagunillas. Still, as Lagunillas cost about US $8 less than does WTI, refiners with sufficient residue conversion capacity can be earning about US $3.50 more in margin per barrel than they can with WTI. Although few refiners would be using a 15/sup 0/ API crude exclusively for any length of time, heavier oil's inclusion in modern refiners' diets is enhancing their competitive position more than any other single factor. This issue of Energy Detente presents the fuel price/tax series and industrial fuel prices for January 1984 for countries of the Western Hemisphere.

  20. A wavelet-MRA-based adaptive semi-Lagrangian method for the relativistic Vlasov-Maxwell system

    SciTech Connect (OSTI)

    Besse, Nicolas Latu, Guillaume Ghizzo, Alain Sonnendruecker, Eric Bertrand, Pierre

    2008-08-10

    In this paper we present a new method for the numerical solution of the relativistic Vlasov-Maxwell system on a phase-space grid using an adaptive semi-Lagrangian method. The adaptivity is performed through a wavelet multiresolution analysis, which gives a powerful and natural refinement criterion based on the local measurement of the approximation error and regularity of the distribution function. Therefore, the multiscale expansion of the distribution function allows to get a sparse representation of the data and thus save memory space and CPU time. We apply this numerical scheme to reduced Vlasov-Maxwell systems arising in laser-plasma physics. Interaction of relativistically strong laser pulses with overdense plasma slabs is investigated. These Vlasov simulations revealed a rich variety of phenomena associated with the fast particle dynamics induced by electromagnetic waves as electron trapping, particle acceleration, and electron plasma wavebreaking. However, the wavelet based adaptive method that we developed here, does not yield significant improvements compared to Vlasov solvers on a uniform mesh due to the substantial overhead that the method introduces. Nonetheless they might be a first step towards more efficient adaptive solvers based on different ideas for the grid refinement or on a more efficient implementation. Here the Vlasov simulations are performed in a two-dimensional phase-space where the development of thin filaments, strongly amplified by relativistic effects requires an important increase of the total number of points of the phase-space grid as they get finer as time goes on. The adaptive method could be more useful in cases where these thin filaments that need to be resolved are a very small fraction of the hyper-volume, which arises in higher dimensions because of the surface-to-volume scaling and the essentially one-dimensional structure of the filaments. Moreover, the main way to improve the efficiency of the adaptive method is to

  1. Unconstrained plastering : all-hexahedral mesh generation via advancing front geometry decomposition (2004-2008).

    SciTech Connect (OSTI)

    Blacker, Teddy Dean; Staten, Matthew L.; Kerr, Robert A.; Owen, Steven James

    2010-03-01

    The generation of all-hexahedral finite element meshes has been an area of ongoing research for the past two decades and remains an open problem. Unconstrained plastering is a new method for generating all-hexahedral finite element meshes on arbitrary volumetric geometries. Starting from an unmeshed volume boundary, unconstrained plastering generates the interior mesh topology without the constraints of a pre-defined boundary mesh. Using advancing fronts, unconstrained plastering forms partially defined hexahedral dual sheets by decomposing the geometry into simple shapes, each of which can be meshed with simple meshing primitives. By breaking from the tradition of previous advancing-front algorithms, which start from pre-meshed boundary surfaces, unconstrained plastering demonstrates that for the tested geometries, high quality, boundary aligned, orientation insensitive, all-hexahedral meshes can be generated automatically without pre-meshing the boundary. Examples are given for meshes from both solid mechanics and geotechnical applications.

  2. Development of an Immersive Environment to Aid in Automatic Mesh Generation LDRD Final Report

    SciTech Connect (OSTI)

    Pavlakos, Constantine J.

    1998-10-01

    The purpose of this work was to explore the use of immersive technologies, such as those used in synthetic environments (commordy referred to as virtual realily, or VR), in enhancing the mesh- generation process for 3-dimensional (3D) engineering models. This work was motivated by the fact that automatic mesh generation systems are still imperfect - meshing algorithms, particularly in 3D, are sometimes unable to construct a mesh to completion, or they may produce anomalies or undesirable complexities in the resulting mesh. It is important that analysts and meshing code developers be able to study their meshes effectively in order to understand the topology and qualily of their meshes. We have implemented prototype capabilities that enable such exploration of meshes in a highly visual and intuitive manner. Since many applications are making use of increasingly large meshes, we have also investigated approaches to handle large meshes while maintaining interactive response. Ideally, it would also be possible to interact with the meshing process, allowing interactive feedback which corrects problems and/or somehow enables proper completion of the meshing process. We have implemented some functionality towards this end -- in doing so, we have explored software architectures that support such an interactive meshing process. This work has incorporated existing technologies developed at SandiaNational Laboratories, including the CUBIT mesh generation system, and the EIGEN/VR (previously known as MUSE) and FLIGHT systems, which allow applications to make use of immersive technologies and advanced human computer interfaces. 1

  3. Using supercritical fluids to refine hydrocarbons

    DOE Patents [OSTI]

    Yarbro, Stephen Lee

    2014-11-25

    This is a method to reactively refine hydrocarbons, such as heavy oils with API gravities of less than 20.degree. and bitumen-like hydrocarbons with viscosities greater than 1000 cp at standard temperature and pressure using a selected fluid at supercritical conditions. The reaction portion of the method delivers lighter weight, more volatile hydrocarbons to an attached contacting device that operates in mixed subcritical or supercritical modes. This separates the reaction products into portions that are viable for use or sale without further conventional refining and hydro-processing techniques. This method produces valuable products with fewer processing steps, lower costs, increased worker safety due to less processing and handling, allow greater opportunity for new oil field development and subsequent positive economic impact, reduce related carbon dioxide, and wastes typical with conventional refineries.

  4. First-Principles Simulations of High-Speed Combustion and Detonation...

    U.S. Department of Energy (DOE) all webpages (Extended Search)

    Physical model includes multi-species equation of state, viscosity, diffusion, and 8 ... a uniform grid as well as static and dynamic adaptive mesh refinement capabilities

  5. 2011 Advanced Combustion Engine R&D Annual Report

    Office of Energy Efficiency and Renewable Energy (EERE) (indexed site)

    ... the evaluation and refinement of the computer models, ... b) Final hp-Adaptive Mesh (a) (b) Carrington - Los ... Using Cubit http:cubit.sandia.gov for engine grid ...

  6. BoxLib

    Energy Science and Technology Software Center (OSTI)

    2000-10-01

    BoxLib is a C++ foundation library used to aid in constructing parallel grid based Partial Differential Equation (PDE) solvers, particularly for Adaptive Mesh Refinement (AMR) applications.

  7. Turbine component cooling channel mesh with intersection chambers

    DOE Patents [OSTI]

    Lee, Ching-Pang; Marra, John J

    2014-05-06

    A mesh (35) of cooling channels (35A, 35B) with an array of cooling channel intersections (42) in a wall (21, 22) of a turbine component. A mixing chamber (42A-C) at each intersection is wider (W1, W2)) than a width (W) of each of the cooling channels connected to the mixing chamber. The mixing chamber promotes swirl, and slows the coolant for more efficient and uniform cooling. A series of cooling meshes (M1, M2) may be separated by mixing manifolds (44), which may have film cooling holes (46) and/or coolant refresher holes (48).

  8. Genealogy of major U.S. refiners - Energy Information Administration

    U.S. Energy Information Administration (EIA) (indexed site)

    Genealogy of Major U.S. Refiners Release date: September 18, 2013 figre 1. World energy consumption, 1990-2040. The structure of the U.S. petroleum refining industry has changed ...

  9. ,"Residual Fuel Oil Sales to End Users Refiner Sales Volumes...

    U.S. Energy Information Administration (EIA) (indexed site)

    Data for" ,"Data 1","Residual Fuel Oil Sales to End Users Refiner Sales ... "Back to Contents","Data 1: Residual Fuel Oil Sales to End Users Refiner Sales Volumes" ...

  10. Grain Refinement of Permanent Mold Cast Copper Base Alloys

    SciTech Connect (OSTI)

    M.Sadayappan; J.P.Thomson; M.Elboujdaini; G.Ping Gu; M. Sahoo

    2005-04-01

    Grain refinement is a well established process for many cast and wrought alloys. The mechanical properties of various alloys could be enhanced by reducing the grain size. Refinement is also known to improve casting characteristics such as fluidity and hot tearing. Grain refinement of copper-base alloys is not widely used, especially in sand casting process. However, in permanent mold casting of copper alloys it is now common to use grain refinement to counteract the problem of severe hot tearing which also improves the pressure tightness of plumbing components. The mechanism of grain refinement in copper-base alloys is not well understood. The issues to be studied include the effect of minor alloy additions on the microstructure, their interaction with the grain refiner, effect of cooling rate, and loss of grain refinement (fading). In this investigation, efforts were made to explore and understand grain refinement of copper alloys, especially in permanent mold casting conditions.

  11. Bandwidth Study U.S. Petroleum Refining | Department of Energy

    Office of Energy Efficiency and Renewable Energy (EERE) (indexed site)

    Petroleum Refining Bandwidth Study U.S. Petroleum Refining Bandwidth Study U.S. Petroleum Refining Energy bandwidth studies of U.S. manufacturing sectors can serve as foundational references in framing the range (or bandwidth) of potential energy savings opportunities. This bandwidth study examines energy consumption and potential energy savings opportunities in U.S. petroleum refining. The study relies on multiple sources to estimate the energy used in nine individual process areas,

  12. ITP Petroleum Refining: Impacts of Condition Assessment on Energy Use:

    Office of Energy Efficiency and Renewable Energy (EERE) (indexed site)

    Selected Applications in Chemicals Processing and Petroleum Refining | Department of Energy Impacts of Condition Assessment on Energy Use: Selected Applications in Chemicals Processing and Petroleum Refining ITP Petroleum Refining: Impacts of Condition Assessment on Energy Use: Selected Applications in Chemicals Processing and Petroleum Refining condition_assessment.pdf (319.56 KB) More Documents & Publications Effective Fouling Minimization Increases the Efficiency and Productivity of

  13. Generating unstructured nuclear reactor core meshes in parallel

    DOE PAGES-Beta [OSTI]

    Jain, Rajeev; Tautges, Timothy J.

    2014-10-24

    Recent advances in supercomputers and parallel solver techniques have enabled users to run large simulations problems using millions of processors. Techniques for multiphysics nuclear reactor core simulations are under active development in several countries. Most of these techniques require large unstructured meshes that can be hard to generate in a standalone desktop computers because of high memory requirements, limited processing power, and other complexities. We have previously reported on a hierarchical lattice-based approach for generating reactor core meshes. Here, we describe efforts to exploit coarse-grained parallelism during reactor assembly and reactor core mesh generation processes. We highlight several reactor coremore » examples including a very high temperature reactor, a full-core model of the Korean MONJU reactor, a ¼ pressurized water reactor core, the fast reactor Experimental Breeder Reactor-II core with a XX09 assembly, and an advanced breeder test reactor core. The times required to generate large mesh models, along with speedups obtained from running these problems in parallel, are reported. A graphical user interface to the tools described here has also been developed.« less

  14. Solves Poisson's Equation in Axizymmetric Geometry on a Rectangular Mesh

    Energy Science and Technology Software Center (OSTI)

    1996-09-10

    DATHETA4.0 computes the magnetostatic field produced by multiple point current sources in the presence of perfect conductors in axisymmetric geometry. DATHETA4.0 has an interactive user interface and solves Poisson''s equation using the ADI method on a rectangular finite-difference mesh. DATHETA4.0 uncludes models specific to applied-B ion diodes.

  15. Second-order accurate difference schemes on highly irregular meshes

    SciTech Connect (OSTI)

    Manteuffel, T.A.; White, A.B. Jr.

    1988-01-01

    In this paper compact-as-possible second-order accurate difference schemes will be constructed for boundary-value problems of arbitrary order on highly irregular meshes. It will be shown that for equations of order (K) these schemes will have truncation error of order (3/endash/K). This phenomena is known as supraconvergence. 7 refs.

  16. Full Core Multiphysics Simulation with Offline Mesh Deformation

    SciTech Connect (OSTI)

    Merzari, E.; Shemon, E. R.; Yu, Y.; Thomas, J. W.; Obabko, A.; Jain, Rajeev; Mahadevan, Vijay; Solberg, Jerome; Ferencz, R.; Whitesides, R.

    2015-12-21

    In this report, building on previous reports issued in FY13 we describe our continued efforts to integrate thermal/hydraulics, neutronics, and structural mechanics modeling codes to perform coupled analysis of a representative fast sodium-cooled reactor core. The focus of the present report is a full core simulation with off-line mesh deformation.

  17. Parallel performance optimizations on unstructured mesh-based simulations

    DOE PAGES-Beta [OSTI]

    Sarje, Abhinav; Song, Sukhyun; Jacobsen, Douglas; Huck, Kevin; Hollingsworth, Jeffrey; Malony, Allen; Williams, Samuel; Oliker, Leonid

    2015-06-01

    This paper addresses two key parallelization challenges the unstructured mesh-based ocean modeling code, MPAS-Ocean, which uses a mesh based on Voronoi tessellations: (1) load imbalance across processes, and (2) unstructured data access patterns, that inhibit intra- and inter-node performance. Our work analyzes the load imbalance due to naive partitioning of the mesh, and develops methods to generate mesh partitioning with better load balance and reduced communication. Furthermore, we present methods that minimize both inter- and intranode data movement and maximize data reuse. Our techniques include predictive ordering of data elements for higher cache efficiency, as well as communication reduction approaches.more » We present detailed performance data when running on thousands of cores using the Cray XC30 supercomputer and show that our optimization strategies can exceed the original performance by over 2×. Additionally, many of these solutions can be broadly applied to a wide variety of unstructured grid-based computations.« less

  18. Generating unstructured nuclear reactor core meshes in parallel

    SciTech Connect (OSTI)

    Jain, Rajeev; Tautges, Timothy J.

    2014-10-24

    Recent advances in supercomputers and parallel solver techniques have enabled users to run large simulations problems using millions of processors. Techniques for multiphysics nuclear reactor core simulations are under active development in several countries. Most of these techniques require large unstructured meshes that can be hard to generate in a standalone desktop computers because of high memory requirements, limited processing power, and other complexities. We have previously reported on a hierarchical lattice-based approach for generating reactor core meshes. Here, we describe efforts to exploit coarse-grained parallelism during reactor assembly and reactor core mesh generation processes. We highlight several reactor core examples including a very high temperature reactor, a full-core model of the Korean MONJU reactor, a ¼ pressurized water reactor core, the fast reactor Experimental Breeder Reactor-II core with a XX09 assembly, and an advanced breeder test reactor core. The times required to generate large mesh models, along with speedups obtained from running these problems in parallel, are reported. A graphical user interface to the tools described here has also been developed.

  19. Deformable elastic network refinement for low-resolution macromolecular crystallography

    SciTech Connect (OSTI)

    Schröder, Gunnar F.; Levitt, Michael; Brunger, Axel T.

    2014-09-01

    An overview of applications of the deformable elastic network (DEN) refinement method is presented together with recommendations for its optimal usage. Crystals of membrane proteins and protein complexes often diffract to low resolution owing to their intrinsic molecular flexibility, heterogeneity or the mosaic spread of micro-domains. At low resolution, the building and refinement of atomic models is a more challenging task. The deformable elastic network (DEN) refinement method developed previously has been instrumental in the determinion of several structures at low resolution. Here, DEN refinement is reviewed, recommendations for its optimal usage are provided and its limitations are discussed. Representative examples of the application of DEN refinement to challenging cases of refinement at low resolution are presented. These cases include soluble as well as membrane proteins determined at limiting resolutions ranging from 3 to 7 Å. Potential extensions of the DEN refinement technique and future perspectives for the interpretation of low-resolution crystal structures are also discussed.

  20. Pollution prevention in the petroleum refining industry

    SciTech Connect (OSTI)

    Fromm, C.H.; White, S.L.

    1995-09-01

    Pollution prevention (P2) as applied to petroleum refining should seek opportunities to reduce waste by preventing oil/hydrocarbon loss, by decreasing consumption of auxiliary input materials, and by improving conversion of incoming impurities into useful products. This chapter will focus on P2 techniques that have found or could find applications in minimizing or eliminating reducible solid waste and wastewater from the petroleum refining process. Air emissions are not covered. The following commonly encountered wastes are considered in this chapter: oily sludges; spent caustics; spent catalysts; miscellaneous process wastes; wastewater; maintenance and materials handling wastes. Following a brief description of waste components and sources, specific P2 techniques are presented in tabular form for each of these wastestreams. None of the P2 techniques presented is discussed here in any detail--the intent is to give the reader a menu of potentially effective P2 options to consider, along with the references where a more detailed discussion may be found. Some of the options presented were advanced in the original references merely as suggestions or plans for improvement. No effort was made to verify their efficacy or applicability in this compilation.

  1. A Novel Coarsening Method for Scalable and Efficient Mesh Generation

    SciTech Connect (OSTI)

    Yoo, A; Hysom, D; Gunney, B

    2010-12-02

    In this paper, we propose a novel mesh coarsening method called brick coarsening method. The proposed method can be used in conjunction with any graph partitioners and scales to very large meshes. This method reduces problem space by decomposing the original mesh into fixed-size blocks of nodes called bricks, layered in a similar way to conventional brick laying, and then assigning each node of the original mesh to appropriate brick. Our experiments indicate that the proposed method scales to very large meshes while allowing simple RCB partitioner to produce higher-quality partitions with significantly less edge cuts. Our results further indicate that the proposed brick-coarsening method allows more complicated partitioners like PT-Scotch to scale to very large problem size while still maintaining good partitioning performance with relatively good edge-cut metric. Graph partitioning is an important problem that has many scientific and engineering applications in such areas as VLSI design, scientific computing, and resource management. Given a graph G = (V,E), where V is the set of vertices and E is the set of edges, (k-way) graph partitioning problem is to partition the vertices of the graph (V) into k disjoint groups such that each group contains roughly equal number of vertices and the number of edges connecting vertices in different groups is minimized. Graph partitioning plays a key role in large scientific computing, especially in mesh-based computations, as it is used as a tool to minimize the volume of communication and to ensure well-balanced load across computing nodes. The impact of graph partitioning on the reduction of communication can be easily seen, for example, in different iterative methods to solve a sparse system of linear equation. Here, a graph partitioning technique is applied to the matrix, which is basically a graph in which each edge is a non-zero entry in the matrix, to allocate groups of vertices to processors in such a way that many of

  2. L2_Reportable_THM.P701

    U.S. Department of Energy (DOE) all webpages (Extended Search)

    ... 5.1.1 Assessment of Cubit generated meshes ... A Priori Quantitative Mesh Assessment ... mesh resolution. Mesh Refinement Cells Characteristic ...

  3. Extended Virtual Spring Mesh (EVSM): The Distributed Self-Organizing Mobile Ad Hoc Network for Area Exploration

    SciTech Connect (OSTI)

    Kurt Derr

    2011-12-01

    Mobile Ad hoc NETworks (MANETs) are distributed self-organizing networks that can change locations and configure themselves on the fly. This paper focuses on an algorithmic approach for the deployment of a MANET within an enclosed area, such as a building in a disaster scenario, which can provide a robust communication infrastructure for search and rescue operations. While a virtual spring mesh (VSM) algorithm provides scalable, self-organizing, and fault-tolerant capabilities required by aMANET, the VSM lacks the MANET's capabilities of deployment mechanisms for blanket coverage of an area and does not provide an obstacle avoidance mechanism. This paper presents a new technique, an extended VSM (EVSM) algorithm that provides the following novelties: (1) new control laws for exploration and expansion to provide blanket coverage, (2) virtual adaptive springs enabling the mesh to expand as necessary, (3) adapts to communications disturbances by varying the density and movement of mobile nodes, and (4) new metrics to assess the performance of the EVSM algorithm. Simulation results show that EVSM provides up to 16% more coverage and is 3.5 times faster than VSM in environments with eight obstacles.

  4. GMINC: a mesh generator for flow simulations in fractured reservoirs

    SciTech Connect (OSTI)

    Pruess, K.

    1983-03-01

    GMINC is a pre-processor computer program for generating geometrical meshes to be used in modeling fluid and heat flow in fractured porous media. It is based on the method of multiple interacting continua (MINC) as developed by Pruess and Narasimhan. The meshes generated by GMINC are in integral finite difference form, and are compatible with the simulators SHAFT79 and MULKOM. Applications with other integral finite difference simulators are possible, and require slight modifications in input/output formats. This report describes methodology and application of GMINC, including preparation of input decks and sample problems. A rather comprehensive overview of the MINC-method is also provided to make the presentation self-contained as a guide for modeling of flow in naturally fractured media.

  5. Surface micromachined counter-meshing gears discrimination device

    DOE Patents [OSTI]

    Polosky, Marc A.; Garcia, Ernest J.; Allen, James J.

    2000-12-12

    A surface micromachined Counter-Meshing Gears (CMG) discrimination device which functions as a mechanically coded lock. Each of two CMG has a first portion of its perimeter devoted to continuous driving teeth that mesh with respective pinion gears. Each EMG also has a second portion of its perimeter devoted to regularly spaced discrimination gear teeth that extend outwardly on at least one of three levels of the CMG. The discrimination gear teeth are designed so as to pass each other without interference only if the correct sequence of partial rotations of the CMG occurs in response to a coded series of rotations from the pinion gears. A 24 bit code is normally input to unlock the device. Once unlocked, the device provides a path for an energy or information signal to pass through the device. The device is designed to immediately lock up if any portion of the 24 bit code is incorrect.

  6. A General-Purpose Mesh Generator for Finite Element Codes.

    Energy Science and Technology Software Center (OSTI)

    1984-02-28

    Version 00 INGEN is a general-purpose mesh generator for use in conjunction with two and three dimensional finite element programs. The basic components of INGEN are surface and three-dimensional region generators that use linear-blending interpolation formulae. These generators are based on an i, j, k index scheme, which is used to number nodal points, construct elements, and develop displacement and traction boundary conditions.

  7. 3D unstructured-mesh radiation transport codes

    SciTech Connect (OSTI)

    Morel, J.

    1997-12-31

    Three unstructured-mesh radiation transport codes are currently being developed at Los Alamos National Laboratory. The first code is ATTILA, which uses an unstructured tetrahedral mesh in conjunction with standard Sn (discrete-ordinates) angular discretization, standard multigroup energy discretization, and linear-discontinuous spatial differencing. ATTILA solves the standard first-order form of the transport equation using source iteration in conjunction with diffusion-synthetic acceleration of the within-group source iterations. DANTE is designed to run primarily on workstations. The second code is DANTE, which uses a hybrid finite-element mesh consisting of arbitrary combinations of hexahedra, wedges, pyramids, and tetrahedra. DANTE solves several second-order self-adjoint forms of the transport equation including the even-parity equation, the odd-parity equation, and a new equation called the self-adjoint angular flux equation. DANTE also offers three angular discretization options: $S{_}n$ (discrete-ordinates), $P{_}n$ (spherical harmonics), and $SP{_}n$ (simplified spherical harmonics). DANTE is designed to run primarily on massively parallel message-passing machines, such as the ASCI-Blue machines at LANL and LLNL. The third code is PERICLES, which uses the same hybrid finite-element mesh as DANTE, but solves the standard first-order form of the transport equation rather than a second-order self-adjoint form. DANTE uses a standard $S{_}n$ discretization in angle in conjunction with trilinear-discontinuous spatial differencing, and diffusion-synthetic acceleration of the within-group source iterations. PERICLES was initially designed to run on workstations, but a version for massively parallel message-passing machines will be built. The three codes will be described in detail and computational results will be presented.

  8. ITP Petroleum Refining: Energy and Environmental Profile of the U.S.

    Office of Energy Efficiency and Renewable Energy (EERE) (indexed site)

    Petroleum Refining Industry (November 2007) | Department of Energy and Environmental Profile of the U.S. Petroleum Refining Industry (November 2007) ITP Petroleum Refining: Energy and Environmental Profile of the U.S. Petroleum Refining Industry (November 2007) profile.pdf (1.62 MB) More Documents & Publications ITP Petroleum Refining: Energy Bandwidth for Petroleum Refining Processes ITP Petroleum Refining: Energy and Environmental Profile of the U.S. Petroleum Refining Industry

  9. MESH2D GRID GENERATOR DESIGN AND USE

    SciTech Connect (OSTI)

    Flach, G.; Smith, F.

    2012-01-20

    Mesh2d is a Fortran90 program designed to generate two-dimensional structured grids of the form [x(i),y(i,j)] where [x,y] are grid coordinates identified by indices (i,j). The x(i) coordinates alone can be used to specify a one-dimensional grid. Because the x-coordinates vary only with the i index, a two-dimensional grid is composed in part of straight vertical lines. However, the nominally horizontal y(i,j{sub 0}) coordinates along index i are permitted to undulate or otherwise vary. Mesh2d also assigns an integer material type to each grid cell, mtyp(i,j), in a user-specified manner. The complete grid is specified through three separate input files defining the x(i), y(i,j), and mtyp(i,j) variations. The overall mesh is constructed from grid zones that are typically then subdivided into a collection of smaller grid cells. The grid zones usually correspond to distinct materials or larger-scale geometric shapes. The structured grid zones are identified through uppercase indices (I,J). Subdivision of zonal regions into grid cells can be done uniformly, or nonuniformly using either a polynomial or geometric skewing algorithm. Grid cells may be concentrated backward, forward, or toward both ends. Figure 1 illustrates the above concepts in the context of a simple four zone grid.

  10. A novel three-dimensional mesh deformation method based on sphere relaxation

    SciTech Connect (OSTI)

    Zhou, Xuan; Li, Shuixiang

    2015-10-01

    In our previous work (2013) [19], we developed a disk relaxation based mesh deformation method for two-dimensional mesh deformation. In this paper, the idea of the disk relaxation is extended to the sphere relaxation for three-dimensional meshes with large deformations. We develop a node based pre-displacement procedure to apply initial movements on nodes according to their layer indices. Afterwards, the nodes are moved locally by the improved sphere relaxation algorithm to transfer boundary deformations and increase the mesh quality. A three-dimensional mesh smoothing method is also adopted to prevent the occurrence of the negative volume of elements, and further improve the mesh quality. Numerical applications in three-dimension including the wing rotation, bending beam and morphing aircraft are carried out. The results demonstrate that the sphere relaxation based approach generates the deformed mesh with high quality, especially regarding complex boundaries and large deformations.

  11. Secretary Bodman Tours Refinery and Calls for More Domestic Refining

    Office of Energy Efficiency and Renewable Energy (EERE) (indexed site)

    Capacity | Department of Energy Refinery and Calls for More Domestic Refining Capacity Secretary Bodman Tours Refinery and Calls for More Domestic Refining Capacity May 18, 2006 - 10:43am Addthis Highlights President Bush's Four-Point Plan to Combat High Energy Prices PORT ARTHUR, TX - Secretary of Energy Samuel W. Bodman today renewed the call for expanded oil refining capacity in the United States and discussed additional steps the Department of Energy (DOE) is taking to prepare for the

  12. REFINING PROGRAM HELPS REENERGIZE NEBRASKA UPGRADES | Department of Energy

    Office of Energy Efficiency and Renewable Energy (EERE) (indexed site)

    REFINING PROGRAM HELPS REENERGIZE NEBRASKA UPGRADES REFINING PROGRAM HELPS REENERGIZE NEBRASKA UPGRADES REFINING PROGRAM HELPS REENERGIZE NEBRASKA UPGRADES In a state where energy costs are low and the home performance workforce had not been established, Nebraska's two largest cities-Omaha and Lincoln-took on the challenge of promoting whole home energy upgrades to homeowners, businesses, and nonprofit organizations. Using $10 million in seed funding from the U.S. Department of Energy's (DOE's)

  13. The Five-Step Development Process Step 3: Project Refinement

    Office of Energy Efficiency and Renewable Energy (EERE) (indexed site)

    3: Project Refinement 2 1 Potential 3 Refinement 4 Implementation 5 Operations & Maintenance 2 Options 3 Refinement 3 FUNDING AND FINANCING OPTIONS Project Ownership Financing structure is highly dependent on size of the project and the capital available for a given project: * Tribe owns the project (cash purchase or debt) * Tribe hosts the project and buys the electricity (power purchase agreement) * Tribe partners with private sector and co-owns the project (uncertainties about receipt of

  14. ,"U.S. Reformulated, Average Refiner Gasoline Prices"

    U.S. Energy Information Administration (EIA) (indexed site)

    ...www.eia.govdnavpetpetprirefmg2cnusepm0rdpgalm.htm" ,"Source:","Energy Information ... Reformulated Gasoline Retail Sales by Refiners (Dollars per ...

  15. ,"U.S. Conventional, Average Refiner Gasoline Prices"

    U.S. Energy Information Administration (EIA) (indexed site)

    ...www.eia.govdnavpetpetprirefmg2cnusepm0udpgalm.htm" ,"Source:","Energy Information ... Conventional Gasoline Retail Sales by Refiners (Dollars per ...

  16. Petroleum Products Table 43. Refiner Motor Gasoline Volumes...

    U.S. Energy Information Administration (EIA) (indexed site)

    of table. 43. Refiner Motor Gasoline Volumes by Grade, Sales Type, PAD District, and State 262 Energy Information Administration Petroleum Marketing Annual 1997 Table 43....

  17. Petroleum Products Table 43. Refiner Motor Gasoline Volumes...

    U.S. Energy Information Administration (EIA) (indexed site)

    1995 Table 43. Refiner Motor Gasoline Volumes by Grade, Sales Type, PAD District, and State (Thousand Gallons per Day) - Continued Geographic Area Month Premium All Grades Sales...

  18. Petroleum Products Table 43. Refiner Motor Gasoline Volumes...

    U.S. Energy Information Administration (EIA) (indexed site)

    2000 Table 43. Refiner Motor Gasoline Volumes by Grade, Sales Type, PAD District, and State (Thousand Gallons per Day) - Continued Geographic Area Month Premium All Grades Sales...

  19. Petroleum Products Table 43. Refiner Motor Gasoline Volumes...

    U.S. Energy Information Administration (EIA) (indexed site)

    of table. 43. Refiner Motor Gasoline Volumes by Grade, Sales Type, PAD District, and State 262 Energy Information Administration Petroleum Marketing Annual 1996 Table 43....

  20. Table 35. Refiner Motor Gasoline Prices by Grade, Sales Type...

    U.S. Energy Information Administration (EIA) (indexed site)

    Energy Information Administration Petroleum Marketing Annual 1995 Table 35. Refiner Motor Gasoline Prices by Grade, Sales Type, PAD District, and State (Cents per Gallon...

  1. Table 44. Refiner Motor Gasoline Volumes by Formulation, Sales...

    U.S. Energy Information Administration (EIA) (indexed site)

    250 Energy Information AdministrationPetroleum Marketing Annual 1999 Table 44. Refiner Motor Gasoline Volumes by Formulation, Sales Type, PAD District, and State (Thousand Gallons...

  2. Table 44. Refiner Motor Gasoline Volumes by Formulation, Sales...

    U.S. Energy Information Administration (EIA) (indexed site)

    Energy Information Administration Petroleum Marketing Annual 1995 Table 44. Refiner Motor Gasoline Volumes by Formulation, Sales Type, PAD District, and State (Thousand Gallons...

  3. Table 35. Refiner Motor Gasoline Prices by Grade, Sales Type...

    U.S. Energy Information Administration (EIA) (indexed site)

    134 Energy Information AdministrationPetroleum Marketing Annual 1998 Table 35. Refiner Motor Gasoline Prices by Grade, Sales Type, PAD District, and State (Cents per Gallon...

  4. Table 35. Refiner Motor Gasoline Prices by Grade, Sales Type...

    U.S. Energy Information Administration (EIA) (indexed site)

    134 Energy Information AdministrationPetroleum Marketing Annual 1999 Table 35. Refiner Motor Gasoline Prices by Grade, Sales Type, PAD District, and State (Cents per Gallon...

  5. Table 43. Refiner Motor Gasoline Volumes by Grade, Sales Type...

    U.S. Energy Information Administration (EIA) (indexed site)

    220 Energy Information AdministrationPetroleum Marketing Annual 1998 Table 43. Refiner Motor Gasoline Volumes by Grade, Sales Type, PAD District, and State (Thousand Gallons per...

  6. Table 44. Refiner Motor Gasoline Volumes by Formulation, Sales...

    U.S. Energy Information Administration (EIA) (indexed site)

    - - - - W W - - - - - - See footnotes at end of table. 44. Refiner Motor Gasoline Volumes by Formulation, Sales Type, PAD District, and State 292 Energy...

  7. Table 44. Refiner Motor Gasoline Volumes by Formulation, Sales...

    U.S. Energy Information Administration (EIA) (indexed site)

    250 Energy Information AdministrationPetroleum Marketing Annual 1998 Table 44. Refiner Motor Gasoline Volumes by Formulation, Sales Type, PAD District, and State (Thousand Gallons...

  8. Table 43. Refiner Motor Gasoline Volumes by Grade, Sales Type...

    U.S. Energy Information Administration (EIA) (indexed site)

    220 Energy Information AdministrationPetroleum Marketing Annual 1999 Table 43. Refiner Motor Gasoline Volumes by Grade, Sales Type, PAD District, and State (Thousand Gallons per...

  9. Table 43. Refiner Motor Gasoline Volumes by Grade, Sales Type...

    U.S. Energy Information Administration (EIA) (indexed site)

    Energy Information Administration Petroleum Marketing Annual 1995 Table 43. Refiner Motor Gasoline Volumes by Grade, Sales Type, PAD District, and State (Thousand Gallons per...

  10. ,"U.S. Total Refiner Petroleum Product Prices"

    U.S. Energy Information Administration (EIA) (indexed site)

    NUSDPG","EMAEPPRPTGNUSDPG","EMAEPPRLPTGNUSDPG","EMAEPPRHPTGNUSDPG" "Date","U.S. Total Gasoline Retail Sales by Refiners (Dollars per Gallon)","U.S. Aviation Gasoline...

  11. Bandwidth Study U.S. Petroleum Refining | Department of Energy

    Office of Energy Efficiency and Renewable Energy (EERE) (indexed site)

    This bandwidth study examines energy consumption and potential energy savings opportunities in U.S. petroleum refining. The study relies on multiple sources to estimate the energy ...

  12. The Space-based Telescopes for Actionable Refinement of Ephemeris...

    Office of Scientific and Technical Information (OSTI)

    Title: The Space-based Telescopes for Actionable Refinement of Ephemeris (STARE) mission Authors: Riot, V ; Devries, W ; Bauman, B ; Simms, L ; Carter, D ; Phillion, D ; Olivier, S ...

  13. The Space-Based Telescopes for Actionable Refinement of Ephemeris...

    Office of Scientific and Technical Information (OSTI)

    Title: The Space-Based Telescopes for Actionable Refinement of Ephemeris Pathfinder Mission Authors: Simms, L ; De Vries, W ; RIot, V ; Olivier, S ; Pertica, A ; Bauman, B ; ...

  14. ITP Petroleum Refining: Petroleum Technology Vision 2020 | Department...

    Office of Energy Efficiency and Renewable Energy (EERE) (indexed site)

    Petroleum Technology Vision 2020 ITP Petroleum Refining: Petroleum Technology Vision 2020 techvision.pdf (684.96 KB) More Documents & Publications Manufacturing Energy and Carbon ...

  15. Refiners react to changes in the pipeline infrastructure

    SciTech Connect (OSTI)

    Giles, K.A.

    1997-06-01

    Petroleum pipelines have long been a critical component in the distribution of crude and refined products in the U.S. Pipelines are typically the most cost efficient mode of transportation for reasonably consistent flow rates. For obvious reasons, inland refineries and consumers are much more dependent on petroleum pipelines to provide supplies of crude and refined products than refineries and consumers located on the coasts. Significant changes in U.S. distribution patterns for crude and refined products are reshaping the pipeline infrastructure and presenting challenges and opportunities for domestic refiners. These changes are discussed.

  16. New Process for Grain Refinement of Aluminum. Final Report

    SciTech Connect (OSTI)

    Dr. Joseph A. Megy

    2000-09-22

    A new method of grain refining aluminum involving in-situ formation of boride nuclei in molten aluminum just prior to casting has been developed in the subject DOE program over the last thirty months by a team consisting of JDC, Inc., Alcoa Technical Center, GRAS, Inc., Touchstone Labs, and GKS Engineering Services. The Manufacturing process to make boron trichloride for grain refining is much simpler than preparing conventional grain refiners, with attendant environmental, capital, and energy savings. The manufacture of boride grain refining nuclei using the fy-Gem process avoids clusters, salt and oxide inclusions that cause quality problems in aluminum today.

  17. ITP Petroleum Refining: Energy Efficiency Roadmap for Petroleum...

    Office of Energy Efficiency and Renewable Energy (EERE) (indexed site)

    Energy Efficiency Roadmap for Petroleum Refineries in California ITP Petroleum Refining: Energy Efficiency Roadmap for Petroleum Refineries in California refiningroadmap.pdf (1.34 ...

  18. The Space-Based Telescopes for Actionable Refinement of Ephemeris...

    Office of Scientific and Technical Information (OSTI)

    Journal Article: The Space-Based Telescopes for Actionable Refinement of Ephemeris Pathfinder Mission Citation Details In-Document Search Title: The Space-Based Telescopes for ...

  19. Adaptive Thresholds

    Energy Science and Technology Software Center (OSTI)

    2014-08-26

    ADAPT is a topological analysis code that allow to compute local threshold, in particular relevance based thresholds for features defined in scalar fields. The initial target application is vortex detection but the software is more generally applicable to all threshold based feature definitions.

  20. Self adaptive methods for parabolic partial differential equations

    SciTech Connect (OSTI)

    Gannon, D.B.

    1980-08-01

    In many applications, the solutions to important partial differential equations are characterized by a sharp active region of transition (such as wave fronts or areas of rapid diffusion) surrounded by relatively calm stable regions. The numerical approximation to such a solution is based on a mesh or grid structure that is best when very fine in the active region and coarse in the calm region. This work considers algorithms for the proper construction of locally refined grids for finite element-based methods for the solution to such problems. Refinement criteria are developed and tested for parabolic problems. The computational complexity of such a strategy is studied, and algorithms based on nested dissection are presented to solve the associated linear algebra problems. 17 figures, 4 tables.

  1. Steel refining with an electrochemical cell

    DOE Patents [OSTI]

    Blander, Milton; Cook, Glenn M.

    1988-01-01

    Apparatus for processing a metallic fluid containing iron oxide, container for a molten metal including an electrically conductive refractory disposed for contact with the molten metal which contains iron oxide, an electrolyte in the form of a basic slag on top of the molten metal, an electrode in the container in contact with the slag electrically separated from the refractory, and means for establishing a voltage across the refractory and the electrode to reduce iron oxide to iron at the surface of the refractory in contact with the iron oxide containing fluid. A process is disclosed for refining an iron product containing not more than about 10% by weight oxygen and not more than about 10% by weight sulfur, comprising providing an electrolyte of a slag containing one or more of calcium oxide, magnesium oxide, silica or alumina, providing a cathode of the iron product in contact with the electrolyte, providing an anode in contact with the electrolyte electrically separated from the cathode, and operating an electrochemical cell formed by the anode, the cathode and the electrolyte to separate oxygen or sulfur present in the iron product therefrom.

  2. Steel refining with an electrochemical cell

    DOE Patents [OSTI]

    Blander, M.; Cook, G.M.

    1988-05-17

    Apparatus is described for processing a metallic fluid containing iron oxide, container for a molten metal including an electrically conductive refractory disposed for contact with the molten metal which contains iron oxide, an electrolyte in the form of a basic slag on top of the molten metal, an electrode in the container in contact with the slag electrically separated from the refractory, and means for establishing a voltage across the refractory and the electrode to reduce iron oxide to iron at the surface of the refractory in contact with the iron oxide containing fluid. A process is disclosed for refining an iron product containing not more than about 10% by weight oxygen and not more than about 10% by weight sulfur, comprising providing an electrolyte of a slag containing one or more of calcium oxide, magnesium oxide, silica or alumina, providing a cathode of the iron product in contact with the electrolyte, providing an anode in contact with the electrolyte electrically separated from the cathode, and operating an electrochemical cell formed by the anode, the cathode and the electrolyte to separate oxygen or sulfur present in the iron product therefrom. 2 figs.

  3. Steel refining with an electrochemical cell

    DOE Patents [OSTI]

    Blander, M.; Cook, G.M.

    1985-05-21

    Disclosed is an apparatus for processing a metallic fluid containing iron oxide, container for a molten metal including an electrically conductive refractory disposed for contact with the molten metal which contains iron oxide, an electrolyte in the form of a basic slag on top of the molten metal, an electrode in the container in contact with the slag electrically separated from the refractory, and means for establishing a voltage across the refractory and the electrode to reduce iron oxide to iron at the surface of the refractory in contact with the iron oxide containing fluid. A process is disclosed for refining an iron product containing not more than about 10% by weight sulfur, comprising providing an electrolyte of a slag containing one or more of calcium oxide, magnesium oxide, silica or alumina, providing a cathode of the iron product in contact with the electrolyte, providing an anode in contact with the electrolyte electrically separated from the cathode, and operating an electrochemical cell formed by the anode, the cathode and the electrolyte to separate oxygen or sulfur present in the iron product therefrom.

  4. Adaptive reconnection-based arbitrary Lagrangian Eulerian method

    DOE PAGES-Beta [OSTI]

    Bo, Wurigen; Shashkov, Mikhail

    2015-07-21

    We present a new adaptive Arbitrary Lagrangian Eulerian (ALE) method. This method is based on the reconnection-based ALE (ReALE) methodology of Refs. [35], [34] and [6]. The main elements in a standard ReALE method are: an explicit Lagrangian phase on an arbitrary polygonal (in 2D) mesh in which the solution and positions of grid nodes are updated; a rezoning phase in which a new grid is defined by changing the connectivity (using Voronoi tessellation) but not the number of cells; and a remapping phase in which the Lagrangian solution is transferred onto the new grid. Furthermore, in the standard ReALEmore » method, the rezoned mesh is smoothed by using one or several steps toward centroidal Voronoi tessellation, but it is not adapted to the solution in any way.« less

  5. Refining and End Use Study of Coal Liquids

    SciTech Connect (OSTI)

    1997-10-01

    This report summarizes revisions to the design basis for the linear programing refining model that is being used in the Refining and End Use Study of Coal Liquids. This revision primarily reflects the addition of data for the upgrading of direct coal liquids.

  6. ,"Motor Gasoline Sales to End Users, Total Refiner Sales Volumes...

    U.S. Energy Information Administration (EIA) (indexed site)

    ... Refiners (Thousand Gallons per Day)","New Mexico Total Gasoline Retail Sales by Refiners ...87,16127.8,1684.4,1377.2,128.8,497.8,835.6,2030.3,1178.7,674.5,56.4,3.9,4678.6,764.1,9.3,1...

  7. ,"No. 2 Distillate Sales to End Users Refiner Sales Volumes"

    U.S. Energy Information Administration (EIA) (indexed site)

    ... Refiners (Thousand Gallons per Day)","New Mexico No 2 Distillate Retail Sales by Refiners ...57.7,6018.7,64.6,101.5,691.5,1553.8,1576.9,2030.5,4320.3,1350.4,683.2,792.4,316.4,804.3,37...

  8. Reitveld refinement study of PLZT ceramics

    SciTech Connect (OSTI)

    Kumar, Rakesh; Bavbande, D. V.; Bafna, V. H.; Mohan, D.; Kothiyal, G. P.; Mishra, R.

    2013-02-05

    PLZT ceramics of composition Pb{sub 0.93}La{sub 0.07}(Zr{sub 0.60}Ti{sub 0.40})O{sub 3}, have been milled for 6hrs and 24hrs were prepared by solid state synthesis route. The 6hrs milled and 24hrs milled samples are represented as PLZT-6 and PLZT-24 ceramics respectively. X-ray diffraction (XRD) pattern was recorded at room temperature. The XRD pattern has been analyzed by employing Rietveld refinement method. Phase identification shows that all the peaks observed in PLZT-6 and PLZT-24 ceramics could be indexed to P4mm space group with tetragonal symmetry. The unit cell parameters of 6hrs milled PLZT ceramics are found to be a=b=4.0781(5)A and c=4.0938(7)A and for 24hrs milled PLZT ceramics unit cell parameters are a=b=4.0679(4)A and c=4.1010(5)A . The axial ratio c/a and unit cell volume of PLZT-6 are 1.0038 and 68.09(2)A{sup 3} respectively. In PLZT-24 samples, the axial ratio c/a value is 1.0080 which is little more than that of the 6hr milled PLZT sample whereas the unit cell volume decrease to 67.88 (1) A{sup 3}. An average crystallite size was estimated by using Scherrer's formula. Dielectric properties were obtained by measuring the capacitance and tand loss using Stanford LCR meter.

  9. Adaptive sampler

    DOE Patents [OSTI]

    Watson, Bobby L.; Aeby, Ian

    1982-01-01

    An adaptive data compression device for compressing data having variable frequency content, including a plurality of digital filters for analyzing the content of the data over a plurality of frequency regions, a memory, and a control logic circuit for generating a variable rate memory clock corresponding to the analyzed frequency content of the data in the frequency region and for clocking the data into the memory in response to the variable rate memory clock.

  10. Adaptive sampler

    DOE Patents [OSTI]

    Watson, B.L.; Aeby, I.

    1980-08-26

    An adaptive data compression device for compressing data is described. The device has a frequency content, including a plurality of digital filters for analyzing the content of the data over a plurality of frequency regions, a memory, and a control logic circuit for generating a variable rate memory clock corresponding to the analyzed frequency content of the data in the frequency region and for clocking the data into the memory in response to the variable rate memory clock.

  11. Unconstrained paving and plastering method for generating finite element meshes

    DOE Patents [OSTI]

    Staten, Matthew L.; Owen, Steven J.; Blacker, Teddy D.; Kerr, Robert

    2010-03-02

    Computer software for and a method of generating a conformal all quadrilateral or hexahedral mesh comprising selecting an object with unmeshed boundaries and performing the following while unmeshed voids are larger than twice a desired element size and unrecognizable as either a midpoint subdividable or pave-and-sweepable polyhedra: selecting a front to advance; based on sizes of fronts and angles with adjacent fronts, determining which adjacent fronts should be advanced with the selected front; advancing the fronts; detecting proximities with other nearby fronts; resolving any found proximities; forming quadrilaterals or unconstrained columns of hexahedra where two layers cross; and establishing hexahedral elements where three layers cross.

  12. LayTracks3D: A new approach for meshing general solids using medial axis transform

    SciTech Connect (OSTI)

    Quadros, William Roshan

    2015-08-22

    This study presents an extension of the all-quad meshing algorithm called LayTracks to generate high quality hex-dominant meshes of general solids. LayTracks3D uses the mapping between the Medial Axis (MA) and the boundary of the 3D domain to decompose complex 3D domains into simpler domains called Tracks. Tracks in 3D have no branches and are symmetric, non-intersecting, orthogonal to the boundary, and the shortest path from the MA to the boundary. These properties of tracks result in desired meshes with near cube shape elements at the boundary, structured mesh along the boundary normal with any irregular nodes restricted to the MA, and sharp boundary feature preservation. The algorithm has been tested on a few industrial CAD models and hex-dominant meshes are shown in the Results section. Work is underway to extend LayTracks3D to generate all-hex meshes.

  13. Final Technical Report: Global Field Aligned Mesh and Gyrokinetic Field Solver in a Tokamak Edge Geometry

    SciTech Connect (OSTI)

    Cummings, Julian C.

    2013-05-15

    This project was a collaboration between researchers at the California Institute of Technology and the University of California, Irvine to investigate the utility of a global field-aligned mesh and gyrokinetic field solver for simulations of the tokamak plasma edge region. Mesh generation software from UC Irvine was tested with specific tokamak edge magnetic geometry scenarios and the quality of the meshes and the solutions to the gyrokinetic Poisson equation were evaluated.

  14. Generating meshes for finite-difference analysis using a solid modeler

    SciTech Connect (OSTI)

    Laguna, G.W.; White, W.T.; Cabral, B.K.

    1987-09-01

    One tool used by the Engineering Research Division of LLNL to help analyze the behavior of electronic systems in hostile environments is 3D finite-difference time-domain (FDTD) computation. FDTD codes solve Maxwell's equations,the differential equations of electromagnetism, on a uniform lattice of points. It is this uniform lattice, or ''mesh,'' that distinguishes finite-difference codes from other codes. The simple mesh makes FDTD codes computationally more efficient than other codes, which enables them to run larger problems and to run faster (up to thirty times faster than finite-element codes, for example). Therefore, within the Engineering Department at LLNL, Electronics Engineering (EE) has initiated a project to develop a mesh generator that will provide meshes suitable for FDTD analysis. This report describes the results of the first year of EE's FDTD Mesh Generation Project. During this year a preliminary version of an automated mesh generator was built and used to create a mesh of an object of interest to the High-Power Microwave Program, namely an electrically detonatable land mine. The code was verified by meshing basic solids such as spheres and cylinders. Because of the design of the code, there is no software limitation to the size of meshes that can be accommodated. The algorithm with a mesh space of approximately 500,000 cells has been demonstrated. The mesh generator can detect certain objects with walls that are thinner than the width of a cell. The code has internal graphics for viewing objects as they appear prior to being converted to a finite-difference representation. Additionally, via data files, the code is coupled to two external graphics packages for visually checking the meshes, namely TAURUS on the Cray and a new code, IMAGE, on the Silicon Graphics IRIS workstation.

  15. Final Report for LDRD Project on Rapid Problem Setup for Mesh-Based Simulation (Rapsodi)

    SciTech Connect (OSTI)

    Brown, D L; Henshaw, W; Petersson, N A; Fast, P; Chand, K

    2003-02-07

    Under LLNL Exploratory Research LDRD funding, the Rapsodi project developed rapid setup technology for computational physics and engineering problems that require computational representations of complex geometry. Many simulation projects at LLNL involve the solution of partial differential equations in complex 3-D geometries. A significant bottleneck in carrying out these simulations arises in converting some specification of a geometry, such as a computer-aided design (CAD) drawing to a computationally appropriate 3-D mesh that can be used for simulation and analysis. Even using state-of-the-art mesh generation software, this problem setup step typically has required weeks or months, which is often much longer than required to carry out the computational simulation itself. The Rapsodi project built computational tools and designed algorithms that help to significantly reduce this setup time to less than a day for many realistic problems. The project targeted rapid setup technology for computational physics and engineering problems that use mixed-element unstructured meshes, overset meshes or Cartesian-embedded boundary (EB) meshes to represent complex geometry. It also built tools that aid in constructing computational representations of geometry for problems that do not require a mesh. While completely automatic mesh generation is extremely difficult, the amount of manual labor required can be significantly reduced. By developing novel, automated, component-based mesh construction procedures and automated CAD geometry repair and cleanup tools, Rapsodi has significantly reduced the amount of hand crafting required to generate geometry and meshes for scientific simulation codes.

  16. Mechanical modeling of graphene using the three-layer-mesh bridging...

    Office of Scientific and Technical Information (OSTI)

    Title: Mechanical modeling of graphene using the three-layer-mesh bridging domain method Authors: Sadeghirad, Alireza ; Su, Ninghai ; Liu, Feng Publication Date: 2015-09-01 OSTI ...

  17. Glass Fiber Mesh Method of Joining for Solid Oxide Fuel Cells...

    U.S. Department of Energy (DOE) all webpages (Extended Search)

    Glass Fiber Mesh Method of Joining for Solid Oxide Fuel Cells Pacific Northwest National Laboratory Contact PNNL About This Technology A simple schematic shows the physical...

  18. Integrated process for the solvent refining of coal

    DOE Patents [OSTI]

    Garg, Diwakar

    1983-01-01

    A process is set forth for the integrated liquefaction of coal by the catalytic solvent refining of a feed coal in a first stage to liquid and solid products and the catalytic hydrogenation of the solid product in a second stage to produce additional liquid product. A fresh inexpensive, throw-away catalyst is utilized in the second stage hydrogenation of the solid product and this catalyst is recovered and recycled for catalyst duty in the solvent refining stage without any activation steps performed on the used catalyst prior to its use in the solvent refining of feed coal.

  19. COLLABORATIVE RESEARCH: CONTINUOUS DYNAMIC GRID ADAPTATION IN A GLOBAL ATMOSPHERIC MODEL: APPLICATION AND REFINEMENT

    SciTech Connect (OSTI)

    Prusa, Joseph

    2012-05-08

    This project had goals of advancing the performance capabilities of the numerical general circulation model EULAG and using it to produce a fully operational atmospheric global climate model (AGCM) that can employ either static or dynamic grid stretching for targeted phenomena. The resulting AGCM combined EULAG's advanced dynamics core with the physics of the NCAR Community Atmospheric Model (CAM). Effort discussed below shows how we improved model performance and tested both EULAG and the coupled CAM-EULAG in several ways to demonstrate the grid stretching and ability to simulate very well a wide range of scales, that is, multi-scale capability. We leveraged our effort through interaction with an international EULAG community that has collectively developed new features and applications of EULAG, which we exploited for our own work summarized here. Overall, the work contributed to over 40 peer- reviewed publications and over 70 conference/workshop/seminar presentations, many of them invited.

  20. Table 43. Refiner Motor Gasoline Volumes by Grade, Sales Type...

    U.S. Energy Information Administration (EIA) (indexed site)

    253.2 2,222.4 W W 206.4 134.3 - 340.7 See footnotes at end of table. 43. Refiner Motor Gasoline Volumes by Grade, Sales Type, PAD District, and State 262 Energy Information...

  1. Table 43. Refiner Motor Gasoline Volumes by Grade, Sales Type...

    U.S. Energy Information Administration (EIA) (indexed site)

    150.0 2,026.7 W W 234.5 161.7 - 396.3 See footnotes at end of table. 43. Refiner Motor Gasoline Volumes by Grade, Sales Type, PAD District, and State 262 Energy Information...

  2. May 28 Webinar to Focus on Tribal Energy Project Refinement

    Energy.gov [DOE]

    Register for the Tribal Renewable Energy Project Refinement webinar, which will be held on Wednesday, May 28, 2014, from 11 a.m. to 12:30 p.m. Mountain time.

  3. Waste minimization for selected residuals in the petroleum refining industry

    SciTech Connect (OSTI)

    1996-12-01

    This technical report on residuals in the petroleum refining industry provides an industry overview, process description, and process flow diagrams. It presents residual descriptions for each of the 29 petroleum refining residuals of concern and what source reduction option exist. It reviews the data sources - RCRA Section 2007 surveys, site visits, and journal articles. It also describes major findings and evaluates the quantity and quality of waste minization information for each source.

  4. Hydrogen Piping Experience in Chevron Refining | Department of Energy

    Office of Energy Efficiency and Renewable Energy (EERE) (indexed site)

    Piping Experience in Chevron Refining Hydrogen Piping Experience in Chevron Refining Overall Perspectives: Few problems with hydrogen piping operating at ambient to at least 800F and pressures up to at least 3000psia as long as we stay within well-defined limits hpwgw_chevronrefining_niccolls.pdf (373.32 KB) More Documents & Publications DOE Hydrogen Pipeline Working Group Workshop Hydrogen Pipeline Working Group Workshop: Code for Hydrogen Pipelines A Review of Stress Corrosion

  5. EERE Success Story-Refining Bio-Oil alongside Petroleum | Department...

    Office of Environmental Management (EM)

    Refining Bio-Oil alongside Petroleum EERE Success Story-Refining Bio-Oil alongside Petroleum April 9, 2013 - 12:00am Addthis W.R. Grace, a leading provider of refining ...

  6. THM-GTRF: New Spider meshes, New Hydra-TH runs

    SciTech Connect (OSTI)

    Bakosi, Jozsef; Christon, Mark A.; Francois, Marianne M.; Lowrie, Robert B.; Nourgaliev, Robert

    2012-06-20

    Progress is reported on computational capabilities for the grid-to-rod-fretting (GTRF) problem of pressurized water reactors. Numeca's Hexpress/Hybrid mesh generator is demonstrated as an excellent alternative to generating computational meshes for complex flow geometries, such as in GTRF. Mesh assessment is carried out using standard industrial computational fluid dynamics practices. Hydra-TH, a simulation code developed at LANL for reactor thermal-hydraulics, is demonstrated on hybrid meshes, containing different element types. A series of new Hydra-TH calculations has been carried out collecting turbulence statistics. Preliminary results on the newly generated meshes are discussed; full analysis will be documented in the L3 milestone, THM.CFD.P5.05, Sept. 2012.

  7. The US petroleum refining industry in the 1980's

    SciTech Connect (OSTI)

    Not Available

    1990-10-11

    As part of the EIA program on petroleum, The US Petroleum Refining Industry in the 1980's, presents a historical analysis of the changes that took place in the US petroleum refining industry during the 1980's. It is intended to be of interest to analysts in the petroleum industry, state and federal government officials, Congress, and the general public. The report consists of six chapters and four appendices. Included is a detailed description of the major events and factors that affected the domestic refining industry during this period. Some of the changes that took place in the 1980's are the result of events that started in the 1970's. The impact of these events on US refinery configuration, operations, economics, and company ownership are examined. 23 figs., 11 tabs.

  8. Trends in heavy oil production and refining in California

    SciTech Connect (OSTI)

    Olsen, D.K.; Ramzel, E.B.; Pendergrass, R.A. II

    1992-07-01

    This report is one of a series of publications assessing the feasibility of increasing domestic heavy oil production and is part of a study being conducted for the US Department of Energy. This report summarizes trends in oil production and refining in Canada. Heavy oil (10{degrees} to 20{degrees} API gravity) production in California has increased from 20% of the state`s total oil production in the early 1940s to 70% in the late 1980s. In each of the three principal petroleum producing districts (Los Angeles Basin, Coastal Basin, and San Joaquin Valley) oil production has peaked then declined at different times throughout the past 30 years. Thermal production of heavy oil has contributed to making California the largest producer of oil by enhanced oil recovery processes in spite of low oil prices for heavy oil and stringent environmental regulation. Opening of Naval Petroleum Reserve No. 1, Elk Hills (CA) field in 1976, brought about a major new source of light oil at a time when light oil production had greatly declined. Although California is a major petroleum-consuming state, in 1989 the state used 13.3 billion gallons of gasoline or 11.5% of US demand but it contributed substantially to the Nation`s energy production and refining capability. California is the recipient and refines most of Alaska`s 1.7 million barrel per day oil production. With California production, Alaskan oil, and imports brought into California for refining, California has an excess of oil and refined products and is a net exporter to other states. The local surplus of oil inhibits exploitation of California heavy oil resources even though the heavy oil resources exist. Transportation, refining, and competition in the market limit full development of California heavy oil resources.

  9. Trends in heavy oil production and refining in California

    SciTech Connect (OSTI)

    Olsen, D.K.; Ramzel, E.B.; Pendergrass, R.A. II.

    1992-07-01

    This report is one of a series of publications assessing the feasibility of increasing domestic heavy oil production and is part of a study being conducted for the US Department of Energy. This report summarizes trends in oil production and refining in Canada. Heavy oil (10{degrees} to 20{degrees} API gravity) production in California has increased from 20% of the state's total oil production in the early 1940s to 70% in the late 1980s. In each of the three principal petroleum producing districts (Los Angeles Basin, Coastal Basin, and San Joaquin Valley) oil production has peaked then declined at different times throughout the past 30 years. Thermal production of heavy oil has contributed to making California the largest producer of oil by enhanced oil recovery processes in spite of low oil prices for heavy oil and stringent environmental regulation. Opening of Naval Petroleum Reserve No. 1, Elk Hills (CA) field in 1976, brought about a major new source of light oil at a time when light oil production had greatly declined. Although California is a major petroleum-consuming state, in 1989 the state used 13.3 billion gallons of gasoline or 11.5% of US demand but it contributed substantially to the Nation's energy production and refining capability. California is the recipient and refines most of Alaska's 1.7 million barrel per day oil production. With California production, Alaskan oil, and imports brought into California for refining, California has an excess of oil and refined products and is a net exporter to other states. The local surplus of oil inhibits exploitation of California heavy oil resources even though the heavy oil resources exist. Transportation, refining, and competition in the market limit full development of California heavy oil resources.

  10. PROP re-refined oil engine test performance

    SciTech Connect (OSTI)

    Linnard, R.E.

    1980-11-01

    Using conventional, commercially-available nonproprietary (to Phillips) additive treatments, engine test programs have successfully demonstrated Phillips Re-refined Oil Process (PROP) oils' compliance with the performance requirements of MIL-L-46152A and API Services SE/CC. This paper reports on the engine testing experience with PROP refined oils as produced in a full-scale 2 MM GPY PROP plant operating with Buyer-collected used oil feedstocks. Comment is also made on the status of the first two PROP plants, one built for the state of North Carolina and the other for Mohawk Oil Company, Ltd., Vancouver B.C., Canada.

  11. A Method for Connecting Dissimilar Finite Element Meshes in Three Dimensions

    SciTech Connect (OSTI)

    Dohrmann, C.R.; Heinstein, M.W.; Key, S.W.

    1998-11-12

    A method is presented for connecting dissimilar finite element meshes in three dimensions. The method combines the concept of master and slave surfaces with the uniform strain approach for surface, corrections finite elements- By modifyhg the are made to element formulations boundaries of elements on the slave such that first-order patch tests are passed. The method can be used to connect meshes which use different element types. In addition, master and slave surfaces can be designated independently of relative mesh resolutions. Example problems in three-dimensional linear elasticity are presented.

  12. Microfluidic sieve using intertwined, free-standing carbon nanotube mesh as active medium

    DOE Patents [OSTI]

    Bakajin, Olgica; Noy, Aleksandr

    2007-11-06

    A microfluidic sieve having a substrate with a microfluidic channel, and a carbon nanotube mesh. The carbon nanotube mesh is formed from a plurality of intertwined free-standing carbon nanotubes which are fixedly attached within the channel for separating, concentrating, and/or filtering molecules flowed through the channel. In one embodiment, the microfluidic sieve is fabricated by providing a substrate having a microfluidic channel, and growing the intertwined free-standing carbon nanotubes from within the channel to produce the carbon nanotube mesh attached within the channel.

  13. Identifying the primitive path mesh in entangled polymer liquids.

    SciTech Connect (OSTI)

    Sukumaran, Sathish K.; Kremer, Kurt; Grest, Gary Stephen; Everaers, Ralf

    2004-10-01

    Similar to entangled ropes, polymer chains cannot slide through each other. These topological constraints, the so-called entanglements, dominate the viscoelastic behavior of high-molecular-weight polymeric liquids. Tube models of polymer dynamics and rheology are based on the idea that entanglements confine a chain to small fluctuations around a primitive path which follows the coarse-grained chain contour. To establish the microscopic foundation for these highly successful phenomenological models, we have recently introduced a method for identifying the primitive path mesh that characterizes the microscopic topological state of computer-generated conformations of long-chain polymer melts and solutions. Here we give a more detailed account of the algorithm and discuss several key aspects of the analysis that are pertinent for its successful use in analyzing the topology of the polymer configurations. We also present a slight modification of the algorithm that preserves the previously neglected self-entanglements and allows us to distinguish between local self-knots and entanglements between distant sections of the same chain. Our results indicate that the latter make a negligible contribution to the tube and that the contour length between local self-knots, N{sub 1k} is significantly larger than the entanglement length N{sub e}.

  14. Modeling and simulation of CVD processes for manufacturing ceramic composites. Final report, 30 September 1994-25 June 1995

    SciTech Connect (OSTI)

    Adjerid, S.; Flaherty, J.E.; Hudson, J.B.; Shephard, M.S.; Webster, B.E.

    1995-06-29

    A chemical vapor deposition (CVD) process used to coat crystal sapphire fibers with B-Al2O3 has been mathematically modelled and numerically simulated using adaptive finite element software. This software system is applicable for solving transient and steady partial differential equations and is capable of automatic mesh generation, mesh-order variation, and/or mesh refinement.

  15. Energy Efficiency Improvement in the Petroleum RefiningIndustry

    SciTech Connect (OSTI)

    Worrell, Ernst; Galitsky, Christina

    2005-05-01

    Information has proven to be an important barrier inindustrial energy efficiency improvement. Voluntary government programsaim to assist industry to improve energy efficiency by supplyinginformation on opportunities. ENERGY STAR(R) supports the development ofstrong strategic corporate energy management programs, by providingenergy management information tools and strategies. This paper summarizesENERGY STAR research conducted to develop an Energy Guide for thePetroleum Refining industry. Petroleum refining in the United States isthe largest in the world, providing inputs to virtually every economicsector, including the transport sector and the chemical industry.Refineries spend typically 50 percent of the cash operating costs (e.g.,excluding capital costs and depreciation) on energy, making energy amajor cost factor and also an important opportunity for cost reduction.The petroleum refining industry consumes about 3.1 Quads of primaryenergy, making it the single largest industrial energy user in the UnitedStates. Typically, refineries can economically improve energy efficiencyby 20 percent. The findings suggest that given available resources andtechnology, there are substantial opportunities to reduce energyconsumption cost-effectively in the petroleum refining industry whilemaintaining the quality of the products manufactured.

  16. Source: Energy Information Administration, Form EIA-782A, "Refiners...

    U.S. Energy Information Administration (EIA) (indexed site)

    2. U.S. Refiner Retail Petroleum Product Prices Figure J F M A M J J A S O N D 0 20 40 60 80 100 120 1995 Cents per Gallon Excluding Taxes Kero-jet Propane No. 1 Distillate No. 4...

  17. Source: Energy Information Administration, Form EIA-782A, "Refiners...

    U.S. Energy Information Administration (EIA) (indexed site)

    4. U.S. Refiner Wholesale Petroleum Product Prices Figure J F M A M J J A S O N D 0 20 40 60 80 100 120 1997 Cents per Gallon Excluding Taxes Kero-jet Propane No. 1 Distillate No....

  18. Source: Energy Information Administration, Form EIA-782A, "Refiners...

    U.S. Energy Information Administration (EIA) (indexed site)

    4. U.S. Refiner Wholesale Petroleum Product Prices Figure J F M A M J J A S O N D 0 20 40 60 80 100 120 1995 Cents per Gallon Excluding Taxes Kero-jet Propane No. 1 Distillate No....

  19. Source: Energy Information Administration, Form EIA-782A, "Refiners...

    U.S. Energy Information Administration (EIA) (indexed site)

    2. U.S. Refiner Retail Petroleum Product Prices Figure J F M A M J J A S O N D 0 20 40 60 80 100 120 1996 Cents per Gallon Excluding Taxes Kero-jet Propane No. 1 Distillate No. 4...

  20. Source: Energy Information Administration, Form EIA-782A, "Refiners...

    U.S. Energy Information Administration (EIA) (indexed site)

    Prices J F M A M J J A S O N D 0 10 20 30 40 50 60 70 1995 Cents per Gallon Excluding Taxes Retail < or 1% Wholesale < or 1% Retail > 1% Wholesale > 1% 7. U.S. Refiner Residual...

  1. Source: Energy Information Administration, Form EIA-782A, "Refiners...

    U.S. Energy Information Administration (EIA) (indexed site)

    4. U.S. Refiner Wholesale Petroleum Product Prices Figure J F M A M J J A S O N D 0 20 40 60 80 100 120 1996 Cents per Gallon Excluding Taxes Kero-jet Propane No. 1 Distillate No....

  2. Source: Energy Information Administration, Form EIA-782A, "Refiners...

    U.S. Energy Information Administration (EIA) (indexed site)

    2. U.S. Refiner Retail Petroleum Product Prices Figure J F M A M J J A S O N D 0 20 40 60 80 100 120 1997 Cents per Gallon Excluding Taxes Kero-jet Propane No. 1 Distillate No. 4...

  3. Decontamination of transuranic contaminated metals by melt refining

    SciTech Connect (OSTI)

    Heshmatpour, B.; Copeland, G.L.; Heestand, R.L.

    1983-01-01

    Melt refining of transuranic contaminated metals is a possible decontamination process with the potential advantages of producing metal for reuse and of simplifying chemical analyses. By routinely achieving the 10 nCi/g( about0.1ppm) level by melt refining, scrap metal can be removed from the transuranic waste category. (To demonstrate the effectiveness of this melt refining process, mild steel, stainless steel, nickel, and copper were contaminated with 500 ppm (..mu..g/g) PuO/sub 2/ and melted with various fluxes. The solidified slags and metals were analyzed for their plutonium contents, and corresponding partition ratios for plutonium were calculated. Some metals were double refined in order to study the effect of secondary slag treatment. The initial weight of the slags was also varied to investigate the effect of slag weight on the degree of plutonium removal. In general, all four metals could be decontaminated below 1 ppm (..mu..g/g) Pu ( about100 nCi/g) by a single slag treatment. Doubling the slag weight did not improve decontamination significantly; however, double slag treatment using 5 wt.% slag did decontaminate the metals to below 0.1 ppm (..mu..g/g) Pu (10 nCi/g).)

  4. Table 35. Refiner Motor Gasoline Prices by Grade, Sales Type...

    U.S. Energy Information Administration (EIA) (indexed site)

    71.8 W 70.5 78.9 W 76.0 83.6 W 69.2 75.2 See footnotes at end of table. 35. Refiner Motor Gasoline Prices by Grade, Sales Type, PAD District and State 176 Energy Information...

  5. Table 35. Refiner Motor Gasoline Prices by Grade, Sales Type...

    U.S. Energy Information Administration (EIA) (indexed site)

    W 68.4 70.8 W W 78.6 W 85.7 81.8 W 69.3 73.8 See footnotes at end of table. 35. Refiner Motor Gasoline Prices by Grade, Sales Type, PAD District and State 176 Energy Information...

  6. Process for electroslag refining of uranium and uranium alloys

    DOE Patents [OSTI]

    Lewis, P.S. Jr.; Agee, W.A.; Bullock, J.S. IV; Condon, J.B.

    1975-07-22

    A process is described for electroslag refining of uranium and uranium alloys wherein molten uranium and uranium alloys are melted in a molten layer of a fluoride slag containing up to about 8 weight percent calcium metal. The calcium metal reduces oxides in the uranium and uranium alloys to provide them with an oxygen content of less than 100 parts per million. (auth)

  7. ITP Petroleum Refining: Technology Roadmap for the Petroleum Industry |

    Office of Energy Efficiency and Renewable Energy (EERE) (indexed site)

    Department of Energy Technology Roadmap for the Petroleum Industry ITP Petroleum Refining: Technology Roadmap for the Petroleum Industry petroleumroadmap.pdf (338.1 KB) More Documents & Publications ITP Aluminum: Energy and Environmental Profile of the U.S. Aluminum Industry ITP Aluminum: Technical Working Group on Inert Anode Technologies 2011 Strategic Plan

  8. ,"Conventional Gasoline Sales to End Users, Total Refiner Sales...

    U.S. Energy Information Administration (EIA) (indexed site)

    ... Refiners (Thousand Gallons per Day)","New Mexico Conventional Gasoline Retail Sales by ...928.8,,587,12358.1,196,1145.9,128.8,497.8,,2030.3,,459.7,56.4,3.9,4678.6,764.1,9.3,1677.4,...

  9. SU-E-J-87: Lung Deformable Image Registration Using Surface Mesh Deformation for Dose Distribution Combination

    SciTech Connect (OSTI)

    Labine, A; Carrier, J; Bedwani, S; Chav, R; DeGuise, J

    2014-06-01

    Purpose: To allow a reliable deformable image registration (DIR) method for dose calculation in radiation therapy. This work proposes a performance assessment of a morphological segmentation algorithm that generates a deformation field from lung surface displacements with 4DCT datasets. Methods: From the 4DCT scans of 15 selected patients, the deep exhale phase of the breathing cycle is identified as the reference scan. Varian TPS EclipseTM is used to draw lung contours, which are given as input to the morphological segmentation algorithm. Voxelized contours are smoothed by a Gaussian filter and then transformed into a surface mesh representation. Such mesh is adapted by rigid and elastic deformations to match each subsequent lung volumes. The segmentation efficiency is assessed by comparing the segmented lung contour and the TPS contour considering two volume metrics, defined as Volumetric Overlap Error (VOE) [%] and Relative Volume Difference (RVD) [%] and three surface metrics, defined as Average Symmetric Surface Distance (ASSD) [mm], Root Mean Square Symmetric Surface Distance (RMSSD) [mm] and Maximum Symmetric Surface Distance (MSSD) [mm]. Then, the surface deformation between two breathing phases is determined by the displacement of corresponding vertices in each deformed surface. The lung surface deformation is linearly propagated in the lung volume to generate 3D deformation fields for each breathing phase. Results: The metrics were averaged over the 15 patients and calculated with the same segmentation parameters. The volume metrics obtained are a VOE of 5.2% and a RVD of 2.6%. The surface metrics computed are an ASSD of 0.5 mm, a RMSSD of 0.8 mm and a MSSD of 6.9 mm. Conclusion: This study shows that the morphological segmentation algorithm can provide an automatic method to capture an organ motion from 4DCT scans and translate it into a volume deformation grid needed by DIR method for dose distribution combination.

  10. Construction of hexahedral elements mesh capturing realistic geometries of Bayou Choctaw SPR site

    SciTech Connect (OSTI)

    Park, Byoung Yoon; Roberts, Barry L.

    2015-09-01

    The three-dimensional finite element mesh capturing realistic geometries of Bayou Choctaw site has been constructed using the sonar and seismic survey data obtained from the field. The mesh is consisting of hexahedral elements because the salt constitutive model is coded using hexahedral elements. Various ideas and techniques to construct finite element mesh capturing artificially and naturally formed geometries are provided. The techniques to reduce the number of elements as much as possible to save on computer run time with maintaining the computational accuracy is also introduced. The steps and methodologies could be applied to construct the meshes of Big Hill, Bryan Mound, and West Hackberry strategic petroleum reserve sites. The methodology could be applied to the complicated shape masses for not only various civil and geological structures but also biological applications such as artificial limbs.

  11. Connectivity-based, all-hexahedral mesh generation method and apparatus

    DOE Patents [OSTI]

    Tautges, Timothy James; Mitchell, Scott A.; Blacker, Ted D.; Murdoch, Peter

    1998-01-01

    The present invention is a computer-based method and apparatus for constructing all-hexahedral finite element meshes for finite element analysis. The present invention begins with a three-dimensional geometry and an all-quadrilateral surface mesh, then constructs hexahedral element connectivity from the outer boundary inward, and then resolves invalid connectivity. The result of the present invention is a complete representation of hex mesh connectivity only; actual mesh node locations are determined later. The basic method of the present invention comprises the step of forming hexahedral elements by making crossings of entities referred to as "whisker chords." This step, combined with a seaming operation in space, is shown to be sufficient for meshing simple block problems. Entities that appear when meshing more complex geometries, namely blind chords, merged sheets, and self-intersecting chords, are described. A method for detecting invalid connectivity in space, based on repeated edges, is also described, along with its application to various cases of invalid connectivity introduced and resolved by the method.

  12. Connectivity-based, all-hexahedral mesh generation method and apparatus

    DOE Patents [OSTI]

    Tautges, T.J.; Mitchell, S.A.; Blacker, T.D.; Murdoch, P.

    1998-06-16

    The present invention is a computer-based method and apparatus for constructing all-hexahedral finite element meshes for finite element analysis. The present invention begins with a three-dimensional geometry and an all-quadrilateral surface mesh, then constructs hexahedral element connectivity from the outer boundary inward, and then resolves invalid connectivity. The result of the present invention is a complete representation of hex mesh connectivity only; actual mesh node locations are determined later. The basic method of the present invention comprises the step of forming hexahedral elements by making crossings of entities referred to as ``whisker chords.`` This step, combined with a seaming operation in space, is shown to be sufficient for meshing simple block problems. Entities that appear when meshing more complex geometries, namely blind chords, merged sheets, and self-intersecting chords, are described. A method for detecting invalid connectivity in space, based on repeated edges, is also described, along with its application to various cases of invalid connectivity introduced and resolved by the method. 79 figs.

  13. LayTracks3D: A new approach for meshing general solids using medial axis transform

    DOE PAGES-Beta [OSTI]

    Quadros, William Roshan

    2015-08-22

    This study presents an extension of the all-quad meshing algorithm called LayTracks to generate high quality hex-dominant meshes of general solids. LayTracks3D uses the mapping between the Medial Axis (MA) and the boundary of the 3D domain to decompose complex 3D domains into simpler domains called Tracks. Tracks in 3D have no branches and are symmetric, non-intersecting, orthogonal to the boundary, and the shortest path from the MA to the boundary. These properties of tracks result in desired meshes with near cube shape elements at the boundary, structured mesh along the boundary normal with any irregular nodes restricted to themore » MA, and sharp boundary feature preservation. The algorithm has been tested on a few industrial CAD models and hex-dominant meshes are shown in the Results section. Work is underway to extend LayTracks3D to generate all-hex meshes.« less

  14. REFINING AND END USE STUDY OF COAL LIQUIDS

    SciTech Connect (OSTI)

    Unknown

    2002-01-01

    This document summarizes all of the work conducted as part of the Refining and End Use Study of Coal Liquids. There were several distinct objectives set, as the study developed over time: (1) Demonstration of a Refinery Accepting Coal Liquids; (2) Emissions Screening of Indirect Diesel; (3) Biomass Gasification F-T Modeling; and (4) Updated Gas to Liquids (GTL) Baseline Design/Economic Study.

  15. Environmental Regulations and Changes in Petroleum Refining Operations

    Gasoline and Diesel Fuel Update

    Environmental Regulations and Changes in Petroleum Refining Operations By Tancred C.M. Lidderdale Contents * Introduction * Motor Gasoline Summer Volatility (RVP) Regulations o Table 1. Summer Volatility Regulations for Motor Gasoline o Table 2. Refinery Inputs and Production of Normal Butane o Figure 1. Refinery Inputs and Production of Normal Butane o Table 3. Price Relationship Between Normal Butane and Motor Gasoline o Table 4. Market Price Premium for Low Vapor Pressure (RVP) Gasoline *

  16. Decontamination of steel by melt refining: A literature review

    SciTech Connect (OSTI)

    Ozturk, B.; Fruehan, R.J.

    1994-12-31

    It has been reported that a large amount of metal waste is produced annually by nuclear fuel processing and nuclear power plants. These metal wastes are contaminated with radioactive elements, such as uranium and plutonium. Current Department of Energy guidelines require retrievable storage of all metallic wastes containing transuranic elements above a certain level. Because of high cost, it is important to develop an effective decontamination and volume reduction method for low level contaminated metals. It has been shown by some investigators that a melt refining technique can be used for the processing of the contaminated metal wastes. In this process, contaminated metal is melted wit a suitable flux. The radioactive elements are oxidized and transferred to a slag phase. In order to develop a commercial process it is important to have information on the thermodynamics and kinetics of the removal. Therefore, a literature search was carried out to evaluate the available information on the decontamination uranium and transuranic-contaminated plain steel, copper and stainless steel by melt a refining technique. Emphasis was given to the thermodynamics and kinetics of the removal. Data published in the literature indicate that it is possible to reduce the concentration of radioactive elements to a very low level by the melt refining method. 20 refs.

  17. ,"Kerosene-Type Jet Fuel Sales to End Users Refiner Sales Volumes...

    U.S. Energy Information Administration (EIA) (indexed site)

    Kerosene-Type Jet Fuel Sales to End Users Refiner Sales Volumes" ,"Click worksheet name or ... Data for" ,"Data 1","Kerosene-Type Jet Fuel Sales to End Users Refiner Sales ...

  18. RFA-14-0001 - In the Matter of Commonwealth Oil Refining Company...

    Office of Energy Efficiency and Renewable Energy (EERE) (indexed site)

    RFA-14-0001 - In the Matter of Commonwealth Oil Refining Company, Inc.Commonwealth of Puerto Rico RFA-14-0001 - In the Matter of Commonwealth Oil Refining Company, Inc....

  19. Catalytic hydroprocessing of solvent refined coal to provide a liquid and a solid fuel

    SciTech Connect (OSTI)

    Dabkowski, M.J.; Heck, R.H.; Stein, T.R.

    1980-04-29

    In the hydroprocessing of blends of solvent refined coal and recycle solvent, small pore hydrotreating catalysts cause separation of a solid phase from treating blends containing high concentration of solvent refined coal.

  20. Petroleum Refining Sector (NAICS 324110) Energy and GHG Combustion Emissions Profile, November 2012

    Office of Energy Efficiency and Renewable Energy (EERE) (indexed site)

    69 2.4 PETROLEUM REFINING SECTOR (NAICS 324110) 2.4.1. Overview of the Petroleum Refining Manufacturing Sector Petroleum refining is a complex industry that generates a diverse slate of fuel products and petrochemicals, from gasoline to asphalt. Refining requires a range of processing steps, including distillation, cracking, reforming, and treating. Most of these processes are highly reliant on process heating and steam energy. Petroleum refineries are an essential part of the U.S. economy.

  1. Occupational employment survey, booklet of definitions. Petroleum refining, coal products, and related industries

    SciTech Connect (OSTI)

    Not Available

    1992-01-01

    The publication gives occupational definitions for 149 occupations in the petroleum refining, coal products, and related industries.

  2. Method for generating a mesh representation of a region characterized by a trunk and a branch thereon

    DOE Patents [OSTI]

    Shepherd, Jason; Mitchell, Scott A.; Jankovich, Steven R.; Benzley, Steven E.

    2007-05-15

    The present invention provides a meshing method, called grafting, that lifts the prior art constraint on abutting surfaces, including surfaces that are linking, source/target, or other types of surfaces of the trunk volume. The grafting method locally modifies the structured mesh of the linking surfaces allowing the mesh to conform to additional surface features. Thus, the grafting method can provide a transition between multiple sweep directions extending sweeping algorithms to 23/4-D solids. The method is also suitable for use with non-sweepable volumes; the method provides a transition between meshes generated by methods other than sweeping as well.

  3. A massively parallel adaptive finite element method with dynamic load balancing

    SciTech Connect (OSTI)

    Devine, K.D.; Flaherty, J.E.; Wheat, S.R.; Maccabe, A.B.

    1993-05-01

    We construct massively parallel, adaptive finite element methods for the solution of hyperbolic conservation laws in one and two dimensions. Spatial discretization is performed by a discontinuous Galerkin finite element method using a basis of piecewise Legendre polynomials. Temporal discretization utilizes a Runge-Kutta method. Dissipative fluxes and projection limiting prevent oscillations near solution discontinuities. The resulting method is of high order and may be parallelized efficiently on MIMD computers. We demonstrate parallel efficiency through computations on a 1024-processor nCUBE/2 hypercube. We also present results using adaptive p-refinement to reduce the computational cost of the method. We describe tiling, a dynamic, element-based data migration system. Tiling dynamically maintains global load balance in the adaptive method by overlapping neighborhoods of processors, where each neighborhood performs local load balancing. We demonstrate the effectiveness of the dynamic load balancing with adaptive p-refinement examples.

  4. Environmental control technology for mining, milling, and refining thorium

    SciTech Connect (OSTI)

    Weakley, S.A.; Blahnik, D.E.; Young, J.K.; Bloomster, C.H.

    1980-02-01

    The purpose of this report is to evaluate, in terms of cost and effectiveness, the various environmental control technologies that would be used to control the radioactive wastes generated in the mining, milling, and refining of thorium from domestic resources. The technologies, in order to be considered for study, had to reduce the radioactivity in the waste streams to meet Atomic Energy Commission (10 CFR 20) standards for natural thorium's maximum permissible concentration (MPC) in air and water. Further regulatory standards or licensing requirements, either federal, state, or local, were not examined. The availability and cost of producing thorium from domestic resources is addressed in a companion volume. The objectives of this study were: (1) to identify the major waste streams generated during the mining, milling, and refining of reactor-grade thorium oxide from domestic resources; and (2) to determine the cost and levels of control of existing and advanced environmental control technologies for these waste streams. Six potential domestic deposits of thorium oxide, in addition to stockpiled thorium sludges, are discussed in this report. A summary of the location and characteristics of the potential domestic thorium resources and the mining, milling, and refining processes that will be needed to produce reactor-grade thorium oxide is presented in Section 2. The wastes from existing and potential domestic thorium oxide mines, mills, and refineries are identified in Section 3. Section 3 also presents the state-of-the-art technology and the costs associated with controlling the wastes from the mines, mills, and refineries. In Section 4, the available environmental control technologies for mines, mills, and refineries are assessed. Section 5 presents the cost and effectiveness estimates for the various environmental control technologies applicable to the mine, mill, and refinery for each domestic resource.

  5. Cogeneration handbook for the petroleum refining industry. [Contains glossary

    SciTech Connect (OSTI)

    Fassbender, L.L.; Garrett-Price, B.A.; Moore, N.L.; Fassbender, A.G.; Eakin, D.E.; Gorges, H.A.

    1984-03-01

    The decision of whether to cogenerate involves several considerations, including technical, economic, environmental, legal, and regulatory issues. Each of these issues is addressed separately in this handbook. In addition, a chapter is included on preparing a three-phase work statement, which is needed to guide the design of a cogeneration system. In addition, an annotated bibliography and a glossary of terminology are provided. Appendix A provides an energy-use profile of the petroleum refining industry. Appendices B through O provide specific information that will be called out in subsequent chapters.

  6. Changing Trends in the Refining Industry (released in AEO2006)

    Reports and Publications

    2006-01-01

    There have been some major changes in the U.S. refining industry recently, prompted in part by a significant decline in the quality of imported crude oil and by increasing restrictions on the quality of finished products. As a result, high-quality crudes, such as the West Texas Intermediate (WTI) crude that serves as a benchmark for oil futures on the New York Mercantile Exchange (NYMEX), have been trading at record premiums to the OPEC (Organization of the Petroleum Exporting Countries) Basket price.

  7. Effect of a concave grid mesh in a carbon nanotube-based field emission X-ray source

    SciTech Connect (OSTI)

    Kim, Hyun Suk; Castro, Edward Joseph D.; Lee, Choong Hun

    2014-10-15

    Highlights: • Successful design using a concave grid mesh for the focusing electron. • Much better X-ray image due to the concave grid mesh. • Higher anode current efficiency using the concave grid mesh versus a flat grid mesh. - Abstract: This study introduces a simple approach to improve the X-ray image quality produced by the carbon nanotube (CNT) field emitter X-ray source by altering the geometrical shape of the grid mesh from the conventional flat shape to a concave one in a typical triode structure. The concave shape of the grid electrode increases the effective number of the grid cells in the mesh, which exerted an electric field in the direction of the emitted electrons, thereby increasing the emission current reaching the anode. Furthermore, the curved mesh (concave grid mesh), which was responsible for the extraction of electrons from the field emitter, exhibited a focusing effect on the electron beam trajectory thereby, reducing the focal spot size impinging on the anode and resulted in a better spatial resolution of the X-ray images produced.

  8. Evaluation of Rugged Wireless Mesh Nodes for Use In Emergency Response

    SciTech Connect (OSTI)

    Kevin L Young; Alan M Snyder

    2007-11-01

    During the summer of 2007, engineers at the Idaho National Laboratory (INL) conducted a two-day evaluation of commercially available battery powered, wireless, self-forming mesh nodes for use in emergency response. In this paper, the author describes the fundamentals of this emerging technology, applciations for emergency response and specific results of the technology evaluation conducted at the Idaho National Laboratory.

  9. Adaptive Energy Grid

    U.S. Department of Energy (DOE) all webpages (Extended Search)

    Control of a Flexible, Adaptive Energy Grid "%"&%'&"&()*+%,-.-"(&*"0.-"+.-1&.,2-"+2&01&"%"&3.-,.-"+%.4&"&5.67822& 9"-+%&3.(,"14&:.-&+82&;%+2&+"+2'&<2,"-+(2+&.:&2-...

  10. Fuel and oxygen addition for metal smelting or refining process

    DOE Patents [OSTI]

    Schlichting, Mark R.

    1994-01-01

    A furnace 10 for smelting iron ore and/or refining molten iron 20 is equipped with an overhead pneumatic lance 40, through which a center stream of particulate coal 53 is ejected at high velocity into a slag layer 30. An annular stream of nitrogen or argon 51 enshrouds the coal stream. Oxygen 52 is simultaneously ejected in an annular stream encircling the inert gas stream 51. The interposition of the inert gas stream between the coal and oxygen streams prevents the volatile matter in the coal from combusting before it reaches the slag layer. Heat of combustion is thus more efficiently delivered to the slag, where it is needed to sustain the desired reactions occurring there. A second stream of lower velocity oxygen can be delivered through an outermost annulus 84 to react with carbon monoxide gas rising from slag layer 30, thereby adding still more heat to the furnace.

  11. Fuel and oxygen addition for metal smelting or refining process

    DOE Patents [OSTI]

    Schlichting, M.R.

    1994-11-22

    A furnace for smelting iron ore and/or refining molten iron is equipped with an overhead pneumatic lance, through which a center stream of particulate coal is ejected at high velocity into a slag layer. An annular stream of nitrogen or argon enshrouds the coal stream. Oxygen is simultaneously ejected in an annular stream encircling the inert gas stream. The interposition of the inert gas stream between the coal and oxygen streams prevents the volatile matter in the coal from combusting before it reaches the slag layer. Heat of combustion is thus more efficiently delivered to the slag, where it is needed to sustain the desired reactions occurring there. A second stream of lower velocity oxygen can be delivered through an outermost annulus to react with carbon monoxide gas rising from slag layer, thereby adding still more heat to the furnace. 7 figs.

  12. A case study of energy conservation opportunities in copper refining

    SciTech Connect (OSTI)

    Somers, W.E.; Hughen, M.L.; Kurylko, L.; Stone, J.R.

    1982-07-01

    A study of energy usage and distribution in a copper refinery was conducted in an attempt to determine possible cost savings in operations of the plant. The study covered those processes which were the major users of energy, namely, smelting, anode casting, electrolytic refining, steam generation and distribution, and electricity distribution. The study involved obtaining data of mass and energy flows in the refinery; identifying energy conservation opportunities (ECO's); obtaining price, operating costs, and saving potentials; for each conservation measure; and analyzing the economical viability of each conservation proposal. Potential cost savings were found to be substantial in heat recovery from slag and anode furnace hot gases, modification of the central steam supply system, control, and redistribution of electrical loads, insulation of electrolytic tanks, and changes in the atomization of oil.

  13. A comparative assessment of resource efficiency in petroleum refining

    SciTech Connect (OSTI)

    Han, Jeongwoo; Forman, Grant S.; Elgowainy, Amgad; Cai, Hao; Wang, Michael; DiVita, Vincent B.

    2015-03-25

    Because of increasing environmental and energy security concerns, a detailed understanding of energy efficiency and greenhouse gas (GHG) emissions in the petroleum refining industry is critical for fair and equitable energy and environmental policies. To date, this has proved challenging due in part to the complex nature and variability within refineries. In an effort to simplify energy and emissions refinery analysis, we delineated LP modeling results from 60 large refineries from the US and EU into broad categories based on crude density (API gravity) and heavy product (HP) yields. Product-specific efficiencies and process fuel shares derived from this study were incorporated in Argonne National Laboratory’s GREET life-cycle model, along with regional upstream GHG intensities of crude, natural gas and electricity specific to the US and EU regions. The modeling results suggest that refineries that process relatively heavier crude inputs and have lower yields of HPs generally have lower energy efficiencies and higher GHG emissions than refineries that run lighter crudes with lower yields of HPs. The former types of refineries tend to utilize energy-intensive units which are significant consumers of utilities (heat and electricity) and hydrogen. Among the three groups of refineries studied, the major difference in the energy intensities is due to the amount of purchased natural gas for utilities and hydrogen, while the sum of refinery feed inputs are generally constant. These results highlight the GHG emissions cost a refiner pays to process deep into the barrel to produce more of the desirable fuels with low carbon to hydrogen ratio.

  14. A comparative assessment of resource efficiency in petroleum refining

    DOE PAGES-Beta [OSTI]

    Han, Jeongwoo; Forman, Grant S.; Elgowainy, Amgad; Cai, Hao; Wang, Michael; DiVita, Vincent B.

    2015-03-25

    Because of increasing environmental and energy security concerns, a detailed understanding of energy efficiency and greenhouse gas (GHG) emissions in the petroleum refining industry is critical for fair and equitable energy and environmental policies. To date, this has proved challenging due in part to the complex nature and variability within refineries. In an effort to simplify energy and emissions refinery analysis, we delineated LP modeling results from 60 large refineries from the US and EU into broad categories based on crude density (API gravity) and heavy product (HP) yields. Product-specific efficiencies and process fuel shares derived from this study weremore » incorporated in Argonne National Laboratory’s GREET life-cycle model, along with regional upstream GHG intensities of crude, natural gas and electricity specific to the US and EU regions. The modeling results suggest that refineries that process relatively heavier crude inputs and have lower yields of HPs generally have lower energy efficiencies and higher GHG emissions than refineries that run lighter crudes with lower yields of HPs. The former types of refineries tend to utilize energy-intensive units which are significant consumers of utilities (heat and electricity) and hydrogen. Among the three groups of refineries studied, the major difference in the energy intensities is due to the amount of purchased natural gas for utilities and hydrogen, while the sum of refinery feed inputs are generally constant. These results highlight the GHG emissions cost a refiner pays to process deep into the barrel to produce more of the desirable fuels with low carbon to hydrogen ratio.« less

  15. A Comparative Assessment of Resource Efficiency in Petroleum Refining

    SciTech Connect (OSTI)

    Han, Jeongwoo; Forman, G; Elgowainy, Amgad; Cai, Hao; Wang, Michael; Divita, V

    2015-10-01

    Because of increasing environmental and energy security concerns, a detailed understanding of energy efficiency and greenhouse gas (GHG) emissions in the petroleum refining industry is critical for fair and equitable energy and environmental policies. To date, this has proved challenging due in part to the complex nature and variability within refineries. In an effort to simplify energy and emissions refinery analysis, we delineated LP modeling results from 60 large refineries from the US and EU into broad categories based on crude density (API gravity) and heavy product (HP) yields. Product-specific efficiencies and process fuel shares derived from this study were incorporated in Argonne National Laboratory's GREET life-cycle model, along with regional upstream GHG intensities of crude, natural gas and electricity specific to the US and EU regions. The modeling results suggest that refineries that process relatively heavier crude inputs and have lower yields of HPs generally have lower energy efficiencies and higher GHG emissions than refineries that run lighter crudes with lower yields of HPs. The former types of refineries tend to utilize energy-intensive units which are significant consumers of utilities (heat and electricity) and hydrogen. Among the three groups of refineries studied, the major difference in the energy intensities is due to the amount of purchased natural gas for utilities and hydrogen, while the sum of refinery feed inputs are generally constant. These results highlight the GHG emissions cost a refiner pays to process deep into the barrel to produce more of the desirable fuels with low carbon to hydrogen ratio. (c) 2015 Argonne National Laboratory. Published by Elsevier Ltd.

  16. Evaluation of tropical channel refinement using MPAS-A aquaplanet simulations: TROPICAL CHANNEL REFINEMENT IN MPAS-A

    DOE PAGES-Beta [OSTI]

    Martini, Matus N.; Gustafson, William I.; O'Brien, Travis A.; Ma, Po-Lun

    2015-09-01

    Climate models with variable-resolution grids offer a computationally less expensive way to provide more detailed information at regional scales and increased accuracy for processes that cannot be resolved by a coarser grid. This study uses the Model for Prediction Across Scales–Atmosphere (MPAS22A), consisting of a nonhydrostatic dynamical core and a subset of Advanced Research Weather Research and Forecasting (ARW-WRF) model atmospheric physics that have been modified to include the Community Atmosphere Model version 5 (CAM5) cloud fraction parameterization, to investigate the potential benefits of using increased resolution in an tropical channel. The simulations are performed with an idealized aquaplanet configurationmore » using two quasi-uniform grids, with 30 km and 240 km grid spacing, and two variable-resolution grids spanning the same grid spacing range; one with a narrow (20°S–20°N) and one with a wide (30°S–30°N) tropical channel refinement. Results show that increasing resolution in the tropics impacts both the tropical and extratropical circulation. Compared to the quasi-uniform coarse grid, the narrow-channel simulation exhibits stronger updrafts in the Ferrel cell as well as in the middle of the upward branch of the Hadley cell. The wider tropical channel has a closer correspondence to the 30 km quasi-uniform simulation. However, the total atmospheric poleward energy transports are similar in all simulations. The largest differences are in the low-level cloudiness. The refined channel simulations show improved tropical and extratropical precipitation relative to the global 240 km simulation when compared to the global 30 km simulation. All simulations have a single ITCZ. The relatively small differences in mean global and tropical precipitation rates among the simulations are a promising result, and the evidence points to the tropical channel being an effective method for avoiding the extraneous numerical artifacts seen in earlier

  17. Adaptive Sampling Proxy Application

    Energy Science and Technology Software Center (OSTI)

    2012-10-22

    ASPA is an implementation of an adaptive sampling algorithm [1-3], which is used to reduce the computational expense of computer simulations that couple disparate physical scales. The purpose of ASPA is to encapsulate the algorithms required for adaptive sampling independently from any specific application, so that alternative algorithms and programming models for exascale computers can be investigated more easily.

  18. Parallel, adaptive finite element methods for conservation laws

    SciTech Connect (OSTI)

    Biswas, R.; Devine, K.D.; Flaherty, J.E. Rensselaer Polytechnic Institute, Troy, NY )

    1994-01-01

    We construct parallel finite element methods for the solution of hyperbolic conservation laws in one and two dimensions. Spatial discretization is performed by a discontinuous Galerkin finite element method using a basis of piecewise Legendre polynomials. Temporal discretization utilizes a Runge-Kutta method. Dissipative fluxes and projection limiting prevent oscillations near solution discontinuities. A posteriori estimates of spatial errors are obtained by a p-refinement technique using superconvergence at Radau points. The resulting method is of high order and may be parallelized efficiently on MIMD computers. We compare results using different limiting schemes and demonstrate parallel efficiency through computations on an NCUBE/2 hypercube. We also present results using adaptive h- and p-refinement to reduce the computational cost of the method.

  19. Influence of Alloy and Solidification Parameters on Grain Refinement in Aluminum Weld Metal due to Inoculation

    SciTech Connect (OSTI)

    Schempp, Philipp [BAM, Germany; Tang, Z. [BIAS, Germany; Cross, Carl E. [Los Alamos National Laboratory; Seefeld, T. [BIAS, Germany; Pittner, A. [BAM, Germany; Rethmeier, M. [BAM, Germany

    2012-06-28

    The goals are: (1) Establish how much Ti/B grain refiner is need to completely refine aluminum weld metal for different alloys and different welding conditions; (2) Characterize how alloy composition and solidification parameters affect weld metal grain refinement; and (3) Apply relevant theory to understand observed behavior. Conclusions are: (1) additions of Ti/B grain refiner to weld metal in Alloys 1050, 5083, and 6082 resulted in significant grain refinement; (2) grain refinement was more effective in GTAW than LBW, resulting in finer grains at lower Ti content - reason is limited time available for equiaxed grain growth in LBW (inability to occlude columnar grain growth); (3) welding travel speed did not markedly affect grain size within GTAW and LBW clusters; and (4) application of Hunt CET analysis showed experimental G to be on the order of the critical G{sub CET}; G{sub CET} was consistently higher for GTAW than for LBW.

  20. Just the crude oil, please: The oil imports - refining capacity connection

    SciTech Connect (OSTI)

    Not Available

    1994-04-29

    Steep growth has brought crude oil imports converging with the amount of US crude oil production in 1993. Meanwhile, petroleum product imports into the US have been falling because, among other reasons, only a few refiners outside the US can produce refined products to the specifications of environmentally minded US legislators. As refiners have concentrated investment to produce clean fuels only in select facilities, supply and logistical challenges loom closely in the future.

  1. Impact of Environmental Compliance Costs on U.S. Refining Profitability 1995-2001

    Reports and Publications

    2003-01-01

    This report assesses the effects of pollution abatement requirements on the financial performance of U.S. petroleum refining and marketing operations during the 1995 to 2001 period. This study is a follow-up to the October 1997 publication entitled The Impact of Environmental Compliance Costs on U.S. Refining Profitability, that focused on the financial impacts of U.S. refining pollution abatement investment requirements in the 1988 to1995 period.

  2. ,"U.S. Sales for Resale, Total Refiner Motor Gasoline Sales Volumes...

    U.S. Energy Information Administration (EIA) (indexed site)

    Resale, Total Refiner Motor Gasoline Sales Volumes" ,"Click worksheet name or tab at bottom for data" ,"Worksheet Name","Description"," Of Series","Frequency","Latest Data for" ...

  3. Table 46. Refiner No. 2 Distillate, Diesel Fuel, and Fuel Oil...

    Annual Energy Outlook

    Petroleum Marketing Annual 1999 295 Table 46. Refiner No. 2 Distillate, Diesel Fuel, and Fuel Oil Volumes by PAD District and State (Thousand Gallons per Day) - Continued...

  4. Table A1. Refiner/Reseller Motor Gasoline Prices by Grade, PAD...

    U.S. Energy Information Administration (EIA) (indexed site)

    Information Administration Petroleum Marketing Annual 1995 Table A1. RefinerReseller Motor Gasoline Prices by Grade, PAD District and State, 1984-Present (Cents per Gallon...

  5. Table 6. U.S. Refiner Motor Gasoline Prices by Grade and Sales...

    U.S. Energy Information Administration (EIA) (indexed site)

    Information Administration Petroleum Marketing Annual 1995 Table 6. U.S. Refiner Motor Gasoline Prices by Grade and Sales Type (Cents per Gallon Excluding Taxes) - Continued...

  6. Table A1. Refiner/Reseller Motor Gasoline Prices by Grade, PAD...

    U.S. Energy Information Administration (EIA) (indexed site)

    AdministrationPetroleum Marketing Annual 1999 401 Table A1. RefinerReseller Motor Gasoline Prices by Grade, PAD District and State, 1984-Present (Cents per Gallon...

  7. Table 7. U.S. Refiner Motor Gasoline Volumes by Grade and Sales...

    U.S. Energy Information Administration (EIA) (indexed site)

    Information Administration Petroleum Marketing Annual 1995 Table 7. U.S. Refiner Motor Gasoline Volumes by Grade and Sales Type (Million Gallons per Day) - Continued Year...

  8. Table A2. Refiner/Reseller Prices of Aviation Fuels, Propane...

    Annual Energy Outlook

    Marketing Annual 1999 421 Table A2. RefinerReseller Prices of Aviation Fuels, Propane, and Kerosene, by PAD District, 1983-Present (Cents per Gallon Excluding Taxes) -...

  9. Table A2. Refiner/Reseller Prices of Aviation Fuels, Propane...

    Annual Energy Outlook

    Marketing Annual 1995 467 Table A2. RefinerReseller Prices of Aviation Fuels, Propane, and Kerosene, by PAD District, 1983-Present (Cents per Gallon Excluding Taxes) -...

  10. Table 12. U.S. Refiner Reformulated Motor Gasoline Prices by...

    U.S. Energy Information Administration (EIA) (indexed site)

    retail outlets, e.g., sales to agricultural customers, commercial sales, and industrial sales. Source: Energy Information Administration Form EIA-782A, "Refiners'Gas...

  11. EERE Success Story-Refining Bio-Oil alongside Petroleum | Department of

    Office of Energy Efficiency and Renewable Energy (EERE) (indexed site)

    Energy Refining Bio-Oil alongside Petroleum EERE Success Story-Refining Bio-Oil alongside Petroleum April 9, 2013 - 12:00am Addthis W.R. Grace, a leading provider of refining technologies, and Pacific Northwest National Laboratory (PNNL) are co-leading an effort to accelerate the development of technologies that enable the processing of bio-oils in petroleum refineries. The ability to leverage existing petroleum-refining infrastructure to produce "drop-in" biofuels (biofuels that

  12. Adaptive finite volume methods for time-dependent P.D.E.S.

    SciTech Connect (OSTI)

    Ware, J.; Berzins, M.

    1995-12-31

    The aim of adaptive methods for time-dependent p.d.e.s is to control the numerical error so that it is less than a user-specified tolerance. This error depends on the spatial discretization method, the spatial mesh, the method of time integration and the timestep. The spatial discretization method and positioning of the spatial mesh points should attempt to ensure that the spatial error is controlled to meet the user`s requirements. It is then desirable to integrate the o.d.e. system in time with sufficient accuracy so that the temporal error does not corrupt the spatial accuracy or the reliability of the spatial error estimates. This paper is concerned with the development of a prototype algorithm of this type, based on a cell-centered triangular finite volume scheme, for two space dimensional convection-dominated problems.

  13. Scientific Final Report: COLLABORATIVE RESEARCH: CONTINUOUS DYNAMIC GRID ADAPTATION IN A GLOBAL ATMOSPHERIC MODEL: APPLICATION AND REFINEMENT

    SciTech Connect (OSTI)

    William J. Gutowski; Joseph M. Prusa, Piotr K. Smolarkiewicz

    2012-04-09

    This project had goals of advancing the performance capabilities of the numerical general circulation model EULAG and using it to produce a fully operational atmospheric global climate model (AGCM) that can employ either static or dynamic grid stretching for targeted phenomena. The resulting AGCM combined EULAG's advanced dynamics core with the 'physics' of the NCAR Community Atmospheric Model (CAM). Effort discussed below shows how we improved model performance and tested both EULAG and the coupled CAM-EULAG in several ways to demonstrate the grid stretching and ability to simulate very well a wide range of scales, that is, multi-scale capability. We leveraged our effort through interaction with an international EULAG community that has collectively developed new features and applications of EULAG, which we exploited for our own work summarized here. Overall, the work contributed to over 40 peer-reviewed publications and over 70 conference/workshop/seminar presentations, many of them invited.

  14. On Modeling and Analysis of MIMO Wireless Mesh Networks with Triangular Overlay Topology

    DOE PAGES-Beta [OSTI]

    Cao, Zhanmao; Wu, Chase Q.; Zhang, Yuanping; Shiva, Sajjan G.; Gu, Yi

    2015-01-01

    Multiple input multiple output (MIMO) wireless mesh networks (WMNs) aim to provide the last-mile broadband wireless access to the Internet. Along with the algorithmic development for WMNs, some fundamental mathematical problems also emerge in various aspects such as routing, scheduling, and channel assignment, all of which require an effective mathematical model and rigorous analysis of network properties. In this paper, we propose to employ Cartesian product of graphs (CPG) as a multichannel modeling approach and explore a set of unique properties of triangular WMNs. In each layer of CPG with a single channel, we design a node coordinate scheme thatmore » retains the symmetric property of triangular meshes and develop a function for the assignment of node identity numbers based on their coordinates. We also derive a necessary-sufficient condition for interference-free links and combinatorial formulas to determine the number of the shortest paths for channel realization in triangular WMNs.« less

  15. QMP-MVIA: a message passing system for Linux clusters with gigabit Ethernet mesh connections

    SciTech Connect (OSTI)

    Jie Chen; W. Watson III; Robert Edwards; Weizhen Mao

    2004-09-01

    Recent progress in performance coupled with a decline in price for copper-based gigabit Ethernet (GigE) interconnects makes them an attractive alternative to expensive high speed network interconnects (NIC) when constructing Linux clusters. However traditional message passing systems based on TCP for GigE interconnects cannot fully utilize the raw performance of today's GigE interconnects due to the overhead of kernel involvement and multiple memory copies during sending and receiving messages. The overhead is more evident in the case of mesh connected Linux clusters using multiple GigE interconnects in a single host. We present a general message passing system called QMP-MVIA (QCD Message Passing over M-VIA) for Linux clusters with mesh connections using GigE interconnects. In particular, we evaluate and compare the performance characteristics of TCP and M-VIA (an implementation of the VIA specification) software for a mesh communication architecture to demonstrate the feasibility of using M-VIA as a point-to-point communication software, on which QMP-MVIA is based. Furthermore, we illustrate the design and implementation of QMP-MVIA for mesh connected Linux clusters with emphasis on both point-to-point and collective communications, and demonstrate that QMP-MVIA message passing system using GigE interconnects achieves bandwidth and latency that are not only better than systems based on TCP but also compare favorably to systems using some of the specialized high speed interconnects in a switched architecture at much lower cost.

  16. Translation, Enhancement, Filtering, and Visualization of Large 3D Triangle Mesh

    Energy Science and Technology Software Center (OSTI)

    1997-04-21

    The runthru system consists of five programs: workcell filter, just do it, transl8g, decim8, and runthru. The workcell filter program is useful if the source of your 3D triangle mesh model is IGRIP. It will traverse a directory structure of Deneb IGRIP files and filter out any IGRIP part files that are not referenced by an accompanying IGRIP work cell file. The just do it program automates translating and/or filtering of large numbers of partsmore » that are organized in hierarchical directory structures. The transl8g program facilitates the interchange, topology generation, error checking, and enhancement of large 3D triangle meshes. Such data is frequently used to represent conceptual designs, scientific visualization volume modeling, or discrete sample data. Interchange is provided between several popular commercial and defacto standard geometry formats. Error checking is included to identify duplicate and zero area triangles. Model engancement features include common vertex joining, consistent triangle vertex ordering, vertex noemal vector averaging, and triangle strip generation. Many of the traditional O(n2) algorithms required to provide the above features have been recast and are o(nlog(n)) which support large mesh sizes. The decim8 program is based on a data filter algorithm that significantly reduces the number of triangles required to represent 3D models of geometry, scientific visualization results, and discretely sampled data. It eliminates local patches of triangles whose geometries are not appreciably different and replaces them with fewer, larger triangles. The algorithm has been used to reduce triangles in large conceptual design models to facilitate virtual walk throughs and to enable interactive viewing of large 3D iso-surface volume visualizations. The runthru program provides high performance interactive display and manipulation of 3D triangle mesh models.« less

  17. Environmental regulations and changes in petroleum refining operations

    SciTech Connect (OSTI)

    Lidderdale, T.C.M.

    1996-03-01

    The U.S. petroleum industry has responded to four major new federal rules on motor gasoline product quality in the last 6 years: Phase 1 Summer Volatility (Rvp) Regulation, June 1989; Phase 2 Summer Volatility (Rvp) regulation, May 1992; oxygenated Gasoline, November 1992; and reformulated Gasoline Phase I Simple Model, December 1994. These regulations have generated significant changes in domestic refinery operations, affecting marginal production costs and market prices, refinery yields, and the seasonality of production. Some changes have been dramatic. The price of motor gasoline has increased by as much as 60 {cents}/gal due to regulations. Refinery yields of motor gasoline (refinery output of motor gasoline as a fraction of refinery inputs or total refinery output), which historically peaked in the early summer to meet high summer driving demand, now are highest during the winter months. These changes in domestic refining operations are identified and related to the vapor pressure, oxygenated and reformulated gasoline (RFG) product quality regulations. This analysis uses linear regression equations from the Energy Information Administration`s (EIA) Short-Term Integrated Forecasting System (STIFS). The STIFS model is used for producing forecasts appearing in the EIA`s Short-Term Energy Outlook.

  18. Bioremediation of petroleum wastes from the refining of lubricant oils

    SciTech Connect (OSTI)

    Prince, M.; Sambasivam, Y. )

    1993-02-01

    The results of an initial feasibility study on the bioremediation of sludge are presented. The sludge used in the study was taken from a site containing waste produced during the refining of lubricant oils to which sulfuric acid had been added. The effectiveness of bioremediation was examined using shake flask experiments with indigenous and other bacteria sources and nutrient supplementation. The initial results show limited effectiveness of biological treatment at conditions employing indigenous bacteria and low (2%) sludge concentrations in Bushnell-Haas media. In addition, the indigenous bacteria were seen to degrade the polycyclic aromatic hydrocarbons naphthalene, penanthrene and pyrene which are present at some locations at the site. No apparent degradation of material was seen using conditions of high (30%) sludge concentrations in Bushnell-Haas medium under a variety of conditions. In addition, nutrients were rapidly depleted at these sludge concentrations, with the exception of sulfates which were produced when high sludge concentrations were used. 23 refs., 8 figs., 3 tabs.

  19. Mimetic finite difference method for the stokes problem on polygonal meshes

    SciTech Connect (OSTI)

    Lipnikov, K; Beirao Da Veiga, L; Gyrya, V; Manzini, G

    2009-01-01

    Various approaches to extend the finite element methods to non-traditional elements (pyramids, polyhedra, etc.) have been developed over the last decade. Building of basis functions for such elements is a challenging task and may require extensive geometry analysis. The mimetic finite difference (MFD) method has many similarities with low-order finite element methods. Both methods try to preserve fundamental properties of physical and mathematical models. The essential difference is that the MFD method uses only the surface representation of discrete unknowns to build stiffness and mass matrices. Since no extension inside the mesh element is required, practical implementation of the MFD method is simple for polygonal meshes that may include degenerate and non-convex elements. In this article, we develop a MFD method for the Stokes problem on arbitrary polygonal meshes. The method is constructed for tensor coefficients, which will allow to apply it to the linear elasticity problem. The numerical experiments show the second-order convergence for the velocity variable and the first-order for the pressure.

  20. Microstructure and Mesh Sensitivities of Mesoscale Surrogate Driving Force Measures for Transgranular Fatigue Cracks in Polycrystals

    SciTech Connect (OSTI)

    Castelluccio, Gustavo M.; McDowell, David L.

    2015-05-22

    The number of cycles required to form and grow microstructurally small fatigue cracks in metals exhibits substantial variability, particularly for low applied strain amplitudes. This variability is commonly attributed to the heterogeneity of cyclic plastic deformation within the microstructure, and presents a challenge to minimum life design of fatigue resistant components. Our paper analyzes sources of variability that contribute to the driving force of transgranular fatigue cracks within nucleant grains. We also employ crystal plasticity finite element simulations that explicitly render the polycrystalline microstructure and Fatigue Indicator Parameters (FIPs) averaged over different volume sizes and shapes relative to the anticipated fatigue damage process zone. Volume averaging is necessary to both achieve description of a finite fatigue damage process zone and to regularize mesh dependence in simulations. Furthermore, results from constant amplitude remote applied straining are characterized in terms of the extreme value distributions of volume averaged FIPs. Grain averaged FIP values effectively mitigate mesh sensitivity, but they smear out variability within grains. Volume averaging over bands that encompass critical transgranular slip planes appear to present the most attractive approach to mitigate mesh sensitivity while preserving variability within grains.

  1. A point-centered arbitrary Lagrangian Eulerian hydrodynamic approach for tetrahedral meshes

    SciTech Connect (OSTI)

    Morgan, Nathaniel R.; Waltz, Jacob I.; Burton, Donald E.; Charest, Marc R.; Canfield, Thomas R.; Wohlbier, John G.

    2015-02-24

    We present a three dimensional (3D) arbitrary Lagrangian Eulerian (ALE) hydrodynamic scheme suitable for modeling complex compressible flows on tetrahedral meshes. The new approach stores the conserved variables (mass, momentum, and total energy) at the nodes of the mesh and solves the conservation equations on a control volume surrounding the point. This type of an approach is termed a point-centered hydrodynamic (PCH) method. The conservation equations are discretized using an edge-based finite element (FE) approach with linear basis functions. All fluxes in the new approach are calculated at the center of each tetrahedron. A multidirectional Riemann-like problem is solved at the center of the tetrahedron. The advective fluxes are calculated by solving a 1D Riemann problem on each face of the nodal control volume. A 2-stage RungeKutta method is used to evolve the solution forward in time, where the advective fluxes are part of the temporal integration. The mesh velocity is smoothed by solving a Laplacian equation. The details of the new ALE hydrodynamic scheme are discussed. Results from a range of numerical test problems are presented.

  2. A point-centered arbitrary Lagrangian Eulerian hydrodynamic approach for tetrahedral meshes

    DOE PAGES-Beta [OSTI]

    Morgan, Nathaniel R.; Waltz, Jacob I.; Burton, Donald E.; Charest, Marc R.; Canfield, Thomas R.; Wohlbier, John G.

    2015-02-24

    We present a three dimensional (3D) arbitrary Lagrangian Eulerian (ALE) hydrodynamic scheme suitable for modeling complex compressible flows on tetrahedral meshes. The new approach stores the conserved variables (mass, momentum, and total energy) at the nodes of the mesh and solves the conservation equations on a control volume surrounding the point. This type of an approach is termed a point-centered hydrodynamic (PCH) method. The conservation equations are discretized using an edge-based finite element (FE) approach with linear basis functions. All fluxes in the new approach are calculated at the center of each tetrahedron. A multidirectional Riemann-like problem is solved atmore » the center of the tetrahedron. The advective fluxes are calculated by solving a 1D Riemann problem on each face of the nodal control volume. A 2-stage Runge–Kutta method is used to evolve the solution forward in time, where the advective fluxes are part of the temporal integration. The mesh velocity is smoothed by solving a Laplacian equation. The details of the new ALE hydrodynamic scheme are discussed. Results from a range of numerical test problems are presented.« less

  3. Microstructure and mesh sensitivities of mesoscale surrogate driving force measures for transgranular fatigue cracks in polycrystals

    DOE PAGES-Beta [OSTI]

    Castelluccio, Gustavo M.; McDowell, David L.

    2015-05-22

    The number of cycles required to form and grow microstructurally small fatigue cracks in metals exhibits substantial variability, particularly for low applied strain amplitudes. This variability is commonly attributed to the heterogeneity of cyclic plastic deformation within the microstructure, and presents a challenge to minimum life design of fatigue resistant components. Our paper analyzes sources of variability that contribute to the driving force of transgranular fatigue cracks within nucleant grains. We also employ crystal plasticity finite element simulations that explicitly render the polycrystalline microstructure and Fatigue Indicator Parameters (FIPs) averaged over different volume sizes and shapes relative to the anticipatedmore » fatigue damage process zone. Volume averaging is necessary to both achieve description of a finite fatigue damage process zone and to regularize mesh dependence in simulations. Furthermore, results from constant amplitude remote applied straining are characterized in terms of the extreme value distributions of volume averaged FIPs. Grain averaged FIP values effectively mitigate mesh sensitivity, but they smear out variability within grains. Furthermore, volume averaging over bands that encompass critical transgranular slip planes appear to present the most attractive approach to mitigate mesh sensitivity while preserving variability within grains.« less

  4. Microstructure and mesh sensitivities of mesoscale surrogate driving force measures for transgranular fatigue cracks in polycrystals

    SciTech Connect (OSTI)

    Castelluccio, Gustavo M.; McDowell, David L.

    2015-05-22

    The number of cycles required to form and grow microstructurally small fatigue cracks in metals exhibits substantial variability, particularly for low applied strain amplitudes. This variability is commonly attributed to the heterogeneity of cyclic plastic deformation within the microstructure, and presents a challenge to minimum life design of fatigue resistant components. Our paper analyzes sources of variability that contribute to the driving force of transgranular fatigue cracks within nucleant grains. We also employ crystal plasticity finite element simulations that explicitly render the polycrystalline microstructure and Fatigue Indicator Parameters (FIPs) averaged over different volume sizes and shapes relative to the anticipated fatigue damage process zone. Volume averaging is necessary to both achieve description of a finite fatigue damage process zone and to regularize mesh dependence in simulations. Furthermore, results from constant amplitude remote applied straining are characterized in terms of the extreme value distributions of volume averaged FIPs. Grain averaged FIP values effectively mitigate mesh sensitivity, but they smear out variability within grains. Furthermore, volume averaging over bands that encompass critical transgranular slip planes appear to present the most attractive approach to mitigate mesh sensitivity while preserving variability within grains.

  5. Climate Change Adaptation Planning

    Energy.gov [DOE]

    This course provides an introduction to planning for climate change impacts, with examples of tribes that have been going through the adaptation planning process. The course is intended for tribal...

  6. Leak test adapter for containers

    DOE Patents [OSTI]

    Hallett, Brian H.; Hartley, Michael S.

    1996-01-01

    An adapter is provided for facilitating the charging of containers and leak testing penetration areas. The adapter comprises an adapter body and stem which are secured to the container's penetration areas. The container is then pressurized with a tracer gas. Manipulating the adapter stem installs a penetration plug allowing the adapter to be removed and the penetration to be leak tested with a mass spectrometer. Additionally, a method is provided for using the adapter.

  7. Aspects of Western Refining, Inc.'s Proposed Acquisition of Giant Industries, Inc.

    Reports and Publications

    2006-01-01

    Presentation of company-level, non-proprietary data and relevant aggregate data for U.S. refinery capacity and gasoline marketing of Western Refining and Giant Industries to inform discussions of Western Refining Inc.'s proposed acquisition of Giant Industries Inc. for a total of $1.5 billion, which was announced August 28, 2006.

  8. ,"No. 2 Diesel Fuel Sales to End Users Refiner Sales Volumes...

    U.S. Energy Information Administration (EIA) (indexed site)

    ... Refiners (Thousand Gallons per Day)","New Mexico No 2 Diesel Retail Sales by Refiners ...17.9,1773.9,,,781.9,,3446.1,296.5,,,,129.9,2030.1,,,,182.8,,416.2,,60.5,369.8,1495.2,,76.6...

  9. Impact of oxygenates on petroleum refining, review and forecast

    SciTech Connect (OSTI)

    Unzelman, G.H.

    1995-09-01

    During the coming decade, oxygenates will continue to impact light oil processing and will steadily change the composition of the US gasoline pool. There are several major driving forces that will sustain the gradual influx of oxygen to US gasoline toward the regulatory limits: (1) the positive environmental characteristics of oxygenated compounds, (2) the high-octane quality of ethers that promote elimination of less desirable hydrocarbons and (3) the competitive need for ultra-clean gasoline to compete with alternatives. From 1995 forward, conventional gasoline will gradually shift to RFG (reformulated gasoline) containing a minimum of 2 wt% oxygen and less aromatics. As a result some processing changes, already in motion in the refining industry, will continue. For example, less severe naphtha reforming and cracking innovations to yield more feed for etherification and alkylation. While alternative fuel and vehicle technology will continue to develop, oxygenates in US gasoline will contribute the major alternative dimension to transportation fuel in the foreseeable future. With RFG, internal-combustion engine emissions will be progressively less toxic and lower in photochemical reactivity. The oxygenate mix will favor methyl ethers in spite of the recent methanol price spike. Ethyl ethers will be used on a more limited basis for specific situations where lower volatility and feedstock economics are an advantage. Downstream blending of ethanol will supplement ethers blended at the refinery in situations where economics are more favorable than refinery ethers. Long-range survival of ethanol, as a direct blending agent or feedstock for refinery ethers, depends on one or more of several factors: future crude oil costs, longevity of subsidies and/or mandates, and new production technology based on cellulose yielding ethanol economically competitive with hydrocarbons.

  10. Verification of Adaptive Systems

    SciTech Connect (OSTI)

    Pullum, Laura L; Cui, Xiaohui; Vassev, Emil; Hinchey, Mike; Rouff, Christopher; Buskens, Richard

    2012-01-01

    Adaptive systems are critical for future space and other unmanned and intelligent systems. Verification of these systems is also critical for their use in systems with potential harm to human life or with large financial investments. Due to their nondeterministic nature and extremely large state space, current methods for verification of software systems are not adequate to provide a high level of assurance for them. The combination of stabilization science, high performance computing simulations, compositional verification and traditional verification techniques, plus operational monitors, provides a complete approach to verification and deployment of adaptive systems that has not been used before. This paper gives an overview of this approach.

  11. Influence of Aluminum Content on Grain Refinement and Strength of AZ31 Magnesium GTA Weld Metal

    SciTech Connect (OSTI)

    Babu, N. Kishore; Cross, Carl E.

    2012-06-28

    The goal is to characterize the effect of Al content on AZ31 weld metal, the grain size and strength, and examine role of Al on grain refinement. The approach is to systematically vary the aluminum content of AZ31 weld metal, Measure average grain size in weld metal, and Measure cross-weld tensile properties and hardness. Conclusions are that: (1) increased Al content in AZ31 weld metal results in grain refinement Reason: higher undercooling during solidification; (2) weld metal grain refinement resulted in increased strength & hardness Reason: grain boundary strengthening; and (3) weld metal strength can be raised to wrought base metal levels.

  12. Fact #676: May 23, 2011 U.S. Refiners Produce about 19 Gallons of Gasoline

    Office of Energy Efficiency and Renewable Energy (EERE) (indexed site)

    from a Barrel of Oil | Department of Energy 6: May 23, 2011 U.S. Refiners Produce about 19 Gallons of Gasoline from a Barrel of Oil Fact #676: May 23, 2011 U.S. Refiners Produce about 19 Gallons of Gasoline from a Barrel of Oil A standard U.S. barrel contains 42 gallons of crude oil which yields about 44 gallons of petroleum products. The additional 2 gallons of petroleum products come from refiner gains which result in an additional 6% of product. As shown in the figure below, a little more

  13. FIA-15-0002 - In the Matter of Alon Refining Krotz Springs, Inc. |

    Office of Energy Efficiency and Renewable Energy (EERE) (indexed site)

    Department of Energy 2 - In the Matter of Alon Refining Krotz Springs, Inc. FIA-15-0002 - In the Matter of Alon Refining Krotz Springs, Inc. This Decision concerns an Appeal that Alon Refining Krotz Springs, Inc. (Alon) filed in response to a determination that was issued to it by the Department of Energy's (DOE) Office of Information Resources (OIR). In that determination, the OIR replied to a request for documents that Alon submitted under the Freedom of Information Act (FOIA), 5 U.S.C. §

  14. Parallel adaptive Cartesian upwind methods for shock-driven multiphysics simulation

    SciTech Connect (OSTI)

    Deiterding, Ralf

    2011-01-01

    The multiphysics fluid-structure interaction simulation of shock-loaded thin-walled structures requires the dynamic coupling of a shock-capturing flow solver to a solid mechanics solver for large deformations. By combining a Cartesian embedded boundary approach with dynamic mesh adaptation a generic software framework for such flow solvers has been constructed that allows easy exchange of the specific hydrodynamic finite volume upwind scheme and coupling to various explicit finite element solid dynamics solvers. The paper gives an overview of the computational approach and presents first simulations that couple the software to the general purpose solid dynamics code DYNA3D.

  15. A knowledge-based approach to the adaptive finite element analysis

    SciTech Connect (OSTI)

    Haghighi, K.; Kang, E.

    1995-12-31

    An automatic and knowledge-based finite element mesh generator (INTELMESH), which makes extensive use of interactive computer graphics techniques, has been developed. INTELMESH is designed for planar domains and axisymmetric 3-D structures of elasticity and heat transfer subjected to mechanical and thermal loading. It intelligently identifies the critical regions/points in the problem domain and utilizes the new concepts of substructuring and wave propagation to choose the proper mesh size for them. INTELMESH generates well-shaped triangular elements by applying triangulation and Laplacian smoothing procedures. The adaptive analysis involves the initial finite element analysis and an efficient a-posteriori error analysis and estimation. Once a problem is defined, the system automatically builds a finite element model and analyzes the problem through an automatic iterative process until the error reaches a desired level. It has been shown that the proposed approach which initiates the process with an a-priori, and near optimum mesh of the object, converges to the desired accuracy in less time and at less cost.

  16. INGRID: a three-dimensional mesh generator for modeling nonlinear systems

    SciTech Connect (OSTI)

    Stillman, D.W.; Hallquist, J.O.

    1985-07-01

    INGRID generates complete input files for the codes DYNA3D, NIKE3D, FACET, and TOPAZ3D. Geometries are described primarily using index space concepts which came from the program INGEN. The ideas used in INGEN were reworked into a new method which is both simple and powerful. Interactive graphics in INGRID are patterned after TAURUS, a three-dimensional post-processor, and MAZE, a two-dimensional mesh generator. Much of the coding from MAZE is directly incorporated in INGRID.

  17. Telescope Adaptive Optics Code

    Energy Science and Technology Software Center (OSTI)

    2005-07-28

    The Telescope AO Code has general adaptive optics capabilities plus specialized models for three telescopes with either adaptive optics or active optics systems. It has the capability to generate either single-layer or distributed Kolmogorov turbulence phase screens using the FFT. Missing low order spatial frequencies are added using the Karhunen-Loeve expansion. The phase structure curve is extremely dose to the theoreUcal. Secondly, it has the capability to simulate an adaptive optics control systems. The defaultmore » parameters are those of the Keck II adaptive optics system. Thirdly, it has a general wave optics capability to model the science camera halo due to scintillation from atmospheric turbulence and the telescope optics. Although this capability was implemented for the Gemini telescopes, the only default parameter specific to the Gemini telescopes is the primary mirror diameter. Finally, it has a model for the LSST active optics alignment strategy. This last model is highly specific to the LSST« less

  18. Adaptive sequential controller

    DOE Patents [OSTI]

    El-Sharkawi, Mohamed A.; Xing, Jian; Butler, Nicholas G.; Rodriguez, Alonso

    1994-01-01

    An adaptive sequential controller (50/50') for controlling a circuit breaker (52) or other switching device to substantially eliminate transients on a distribution line caused by closing and opening the circuit breaker. The device adaptively compensates for changes in the response time of the circuit breaker due to aging and environmental effects. A potential transformer (70) provides a reference signal corresponding to the zero crossing of the voltage waveform, and a phase shift comparator circuit (96) compares the reference signal to the time at which any transient was produced when the circuit breaker closed, producing a signal indicative of the adaptive adjustment that should be made. Similarly, in controlling the opening of the circuit breaker, a current transformer (88) provides a reference signal that is compared against the time at which any transient is detected when the circuit breaker last opened. An adaptive adjustment circuit (102) produces a compensation time that is appropriately modified to account for changes in the circuit breaker response, including the effect of ambient conditions and aging. When next opened or closed, the circuit breaker is activated at an appropriately compensated time, so that it closes when the voltage crosses zero and opens when the current crosses zero, minimizing any transients on the distribution line. Phase angle can be used to control the opening of the circuit breaker relative to the reference signal provided by the potential transformer.

  19. Recovery Act - Refinement of Cross Flow Turbine Airfoils

    SciTech Connect (OSTI)

    McEntee, Jarlath

    2013-08-30

    Ocean Renewable Power Company, LLC (ORPC) is a global leader in hydrokinetic technology and project development. ORPC develops hydrokinetic power systems and eco-conscious projects that harness the power of oceans and rivers to create clean, predictable renewable energy. ORPC’s technology consists of a family of modular hydrokinetic power systems: the TidGen® Power System, for use at shallow to medium-depth tidal sites; the RivGen™ Power System, for use at river and estuary sites; and the OCGen® Power System, presently under development, for use at deep tidal and offshore ocean current sites. These power systems convert kinetic energy in moving water into clean, renewable, grid-compatible electric power. The core technology component for all ORPC power systems is its patented turbine generator unit (TGU). The TGU uses proprietary advanced design cross flow (ADCF) turbines to drive an underwater permanent magnet generator mounted at the TGU’s center. It is a gearless, direct-drive system that has the potential for high reliability, requires no lubricants and releases no toxins that could contaminate the surrounding water. The hydrokinetic industry shows tremendous promise as a means of helping reduce the U.S.’s use of fossil fuels and dependence on foreign oil. To exploit this market opportunity, cross-flow hydrokinetic devices need to advance beyond the pre-commercial state and more systematic data about the structure and function of cross-flow hydrokinetic devices is required. This DOE STTR project, “Recovery Act - Refinement of Cross Flow Turbine Airfoils,” refined the cross-flow turbine design process to improve efficiency and performance and developed turbine manufacturing processes appropriate for volume production. The project proposed (1) to overcome the lack of data by extensively studying the properties of cross flow turbines, a particularly competitive design approach for extracting hydrokinetic energy and (2) to help ORPC mature its pre

  20. Table A3. Refiner/Reseller Prices of Distillate and Residual...

    U.S. Energy Information Administration (EIA) (indexed site)

    A3. RefinerReseller Prices of Distillate and Residual Fuel Oils, by PAD District, 1983-Present (Cents per Gallon Excluding Taxes) Geographic Area Year No. 1 Distillate No. 2...

  1. Process for solvent refining of coal using a denitrogenated and dephenolated solvent

    DOE Patents [OSTI]

    Garg, Diwakar (Macungie, PA); Givens, Edwin N. (Bethlehem, PA); Schweighardt, Frank K. (Allentown, PA)

    1984-01-01

    A process is disclosed for the solvent refining of non-anthracitic coal at elevated temperatures and pressure in a hydrogen atmosphere using a hydrocarbon solvent which before being recycled in the solvent refining process is subjected to chemical treatment to extract substantially all nitrogenous and phenolic constituents from the solvent so as to improve the conversion of coal and the production of oil in the solvent refining process. The solvent refining process can be either thermal or catalytic. The extraction of nitrogenous compounds can be performed by acid contact such as hydrogen chloride or fluoride treatment, while phenolic extraction can be performed by caustic contact or contact with a mixture of silica and alumina.

  2. Table 46. Refiner No. 2 Distillate, Diesel Fuel, and Fuel Oil...

    Annual Energy Outlook

    839.2 135.0 1,251.9 See footnotes at end of table. 46. Refiner No. 2 Distillate, Diesel Fuel, and Fuel Oil Volumes by PAD District and State Energy Information Administration ...

  3. Table 13. U.S. Refiner Reformulated Motor Gasoline Volumes by...

    U.S. Energy Information Administration (EIA) (indexed site)

    3.3 3.4 7.9 3.3 W 11.3 See footnotes at end of table. 13. U.S. Refiner Reformulated Motor Gasoline Volumes by Grade and Sales Type 26 Energy Information Administration ...

  4. Table 8. U.S. Refiner Conventional Motor Gasoline Prices by...

    U.S. Energy Information Administration (EIA) (indexed site)

    88.4 87.8 80.1 70.0 NA 72.6 See footnotes at end of table. 8. U.S. Refiner Conventional Motor Gasoline Prices by Grade and Sales Type 16 Energy Information Administration ...

  5. Table 9. U.S. Refiner Conventional Motor Gasoline Volumes by...

    U.S. Energy Information Administration (EIA) (indexed site)

    5.7 5.9 4.4 12.9 NA 17.3 See footnotes at end of table. 9. U.S. Refiner Conventional Motor Gasoline Volumes by Grade and Sales Type 18 Energy Information Administration ...

  6. Table 12. U.S. Refiner Reformulated Motor Gasoline Prices by...

    U.S. Energy Information Administration (EIA) (indexed site)

    92.8 92.5 84.0 72.5 W 80.7 See footnotes at end of table. 12. U.S. Refiner Reformulated Motor Gasoline Prices by Grade and Sales Type 24 Energy Information Administration ...

  7. Table 8. U.S. Refiner Conventional Motor Gasoline Prices by...

    U.S. Energy Information Administration (EIA) (indexed site)

    87.4 86.9 78.3 68.5 W 70.8 See footnotes at end of table. 8. U.S. Refiner Conventional Motor Gasoline Prices by Grade and Sales Type 16 Energy Information Administration ...

  8. Table 12. U.S. Refiner Reformulated Motor Gasoline Prices by...

    U.S. Energy Information Administration (EIA) (indexed site)

    92.4 92.1 83.7 74.1 W 80.9 See footnotes at end of table. 12. U.S. Refiner Reformulated Motor Gasoline Prices by Grade and Sales Type 24 Energy Information Administration ...

  9. Table 10. U.S. Refiner Oxygenated Motor Gasoline Prices by...

    U.S. Energy Information Administration (EIA) (indexed site)

    98.0 98.0 86.6 75.0 - 80.1 See footnotes at end of table. 10. U.S. Refiner Oxygenated Motor Gasoline Prices by Grade and Sales Type 20 Energy Information Administration ...

  10. Table 10. U.S. Refiner Oxygenated Motor Gasoline Prices by...

    U.S. Energy Information Administration (EIA) (indexed site)

    94.0 93.9 83.2 73.8 - 79.3 See footnotes at end of table. 10. U.S. Refiner Oxygenated Motor Gasoline Prices by Grade and Sales Type 20 Energy Information Administration ...

  11. Table 13. U.S. Refiner Reformulated Motor Gasoline Volumes by...

    U.S. Energy Information Administration (EIA) (indexed site)

    3.6 3.7 7.9 3.1 W 11.0 See footnotes at end of table. 13. U.S. Refiner Reformulated Motor Gasoline Volumes by Grade and Sales Type 26 Energy Information Administration ...

  12. Table 7. U.S. Refiner Motor Gasoline Volumes by Grade and Sales...

    U.S. Energy Information Administration (EIA) (indexed site)

    NA 26.6 See footnotes at end of table. 14 Energy Information AdministrationPetroleum Marketing Annual 1999 Table 7. U.S. Refiner Motor Gasoline Volumes by Grade and Sales Type...

  13. Table 7. U.S. Refiner Motor Gasoline Volumes by Grade and Sales...

    U.S. Energy Information Administration (EIA) (indexed site)

    NA 27.4 See footnotes at end of table. 14 Energy Information AdministrationPetroleum Marketing Annual 1998 Table 7. U.S. Refiner Motor Gasoline Volumes by Grade and Sales Type...

  14. Table A2. Refiner/Reseller Prices of Aviation Fuels, Propane...

    Gasoline and Diesel Fuel Update

    - W 73.5 See footnotes at end of table. A2. RefinerReseller Prices of Aviation Fuels, Propane, and Kerosene, by PAD District, 1983-Present Energy Information Administration ...

  15. Table 9. U.S. Refiner Conventional Motor Gasoline Volumes by...

    U.S. Energy Information Administration (EIA) (indexed site)

    0.1 18.7 See footnotes at end of table. 18 Energy Information Administration Petroleum Marketing Annual 1995 Table 9. U.S. Refiner Conventional Motor Gasoline Volumes by Grade...

  16. Energy and Environmental Profile of the U.S. Petroleum Refining Industry

    SciTech Connect (OSTI)

    Pellegrino, Joan; Brueske, Sabine; Carole, Tracy; Andres, Howard

    2007-11-01

    This 2007 report provides an overview of the U.S. petroleum refining industry, including new data on market trends and energy and material consumption, as well as information on environmental performance.

  17. Impact of Environmental Compliance Costs on U.S. Refining Profitability

    Reports and Publications

    1997-01-01

    Assesses the effects of pollution abatement requirements on the financial performance of U.S. petroleum refining and marketing operations. The analysis draws heavily on financial and operating data from the Energy Information Administration's Financial Reporting System (FRS).

  18. Fact #676: May 23, 2011 U.S. Refiners Produce about 19 Gallons...

    Office of Energy Efficiency and Renewable Energy (EERE) (indexed site)

    A standard U.S. barrel contains 42 gallons of crude oil which yields about 44 gallons of ... and 10 gallons of diesel fuel are produced from a barrel of crudeoil by U.S. refiners. ...

  19. Refinements in the Los Alamos model of the prompt fission neutron spectrum

    Office of Scientific and Technical Information (OSTI)

    (Journal Article) | DOE PAGES Published Article: Refinements in the Los Alamos model of the prompt fission neutron spectrum Title: Refinements in the Los Alamos model of the prompt fission neutron spectrum Authors: Madland, D. G. ; Kahler, A. C. Publication Date: 2017-01-01 OSTI Identifier: 1326113 Grant/Contract Number: AC5206NA25396 Type: Published Article Journal Name: Nuclear Physics. A Additional Journal Information: Journal Volume: 957; Journal Issue: C; Related Information: CHORUS

  20. Experimental Study on the Performance of Quenching Mesh for an Equipment Protection during a Hydrogen Combustion

    SciTech Connect (OSTI)

    Seong-Wan Hong; Jin-Ho Song; Hee-Dong Kim

    2006-07-01

    An igniter has been used as one of the important tools for the control of the hydrogen concentration in the containment. However, the hydrogen control method using an igniter is accompanied essentially with a combustion, which may result in damaging the equipment that should be operated during/after severe accidents. In this paper, an equipment protection test during a hydrogen combustion was carried out using a quenching mesh which is a kind of flame arrester. The temperatures at the surface of the model equipment were measured during the hydrogen combustion when the quenching mesh with about a 0.3 mm gap distance surrounded the model equipment. The effects of the initial pressure and the flame velocity were investigated. The surface temperatures of the model equipment were increased with the initial pressure rise for a 10% hydrogen concentration. The flame velocity with 25 m/s had not an effect on the increase of the surface temperatures of the model equipment for a 9% hydrogen concentration. (authors)

  1. A dynamically adaptive multilevel wavelet collocation method for solving partial differential equations in a finite domain

    SciTech Connect (OSTI)

    Valilyev, O.V.; Paolucci, S.

    1996-05-01

    A dynamically adaptive multilevel structure of the algorithm provides a simple way to adapt computational refinements to local demands of the solution. High resolution computations are performed only in regions where sharp transitions occur. The scheme handles general boundary conditions. The method is applied to the solution of the one-dimensional Burgers equation with small viscosity, a moving shock problem, and a nonlinear thermoacoustic wave problem. The results indicate that the method is very accurate and efficient. 16 refs., 9 figs., 2 tab.

  2. Petroleum movements and investments in the refining industry: The impact of worldwide environmental regulations

    SciTech Connect (OSTI)

    Guariguata U., G.

    1995-09-01

    Since the enactment of the US Clean Air Act Amendments of 1990, the worldwide refining industry has aligned itself to become increasing attuned to the future well-being of the environment. Refiners must now develop strategies which address careful selection of crude slates, significant increases and changes in product movements, and upgrading of facilities to meet growing demand--in short, strategies which allow them to make substantial increases in capital investments. The objective of this paper is to determine the regional capital investments refiners must make in order to comply with environmental legislation. The methodology in making this determination was founded on a comprehensive analysis of worldwide petroleum supply/demand and distribution patterns for the coming five years, and included evaluation of a set of linear programming (LP) models based on forecasts for regional product demands and projections of regional specifications. The models considered two scenarios, in which either (1) refinery expansion occurs chiefly in the market consuming regions, or (2) crude producers take control of incremental crude volumes and further expand their planned refining projects and the marketing of refined products. The results of these models, coupled with an understanding of geopolitical situations and economic analyses, provided estimates for capital expenditures for the coming decade. In specific, the following issues were addressed, and are discussed in this paper: refined product trade outlook; crude supply; crude quality; shipping; and capital investments.

  3. Adaptive control for accelerators

    DOE Patents [OSTI]

    Eaton, Lawrie E.; Jachim, Stephen P.; Natter, Eckard F.

    1991-01-01

    An adaptive feedforward control loop is provided to stabilize accelerator beam loading of the radio frequency field in an accelerator cavity during successive pulses of the beam into the cavity. A digital signal processor enables an adaptive algorithm to generate a feedforward error correcting signal functionally determined by the feedback error obtained by a beam pulse loading the cavity after the previous correcting signal was applied to the cavity. Each cavity feedforward correcting signal is successively stored in the digital processor and modified by the feedback error resulting from its application to generate the next feedforward error correcting signal. A feedforward error correcting signal is generated by the digital processor in advance of the beam pulse to enable a composite correcting signal and the beam pulse to arrive concurrently at the cavity.

  4. Grain refinement of permanent mold cast copper base alloys. Final report

    SciTech Connect (OSTI)

    Sadayappan, M.; Thomson, J. P.; Elboujdaini, M.; Gu, G. Ping; Sahoo, M.

    2004-04-29

    Grain refinement behavior of copper alloys cast in permanent molds was investigated. This is one of the least studied subjects in copper alloy castings. Grain refinement is not widely practiced for leaded copper alloys cast in sand molds. Aluminum bronzes and high strength yellow brasses, cast in sand and permanent molds, were usually fine grained due to the presence of more than 2% iron. Grain refinement of the most common permanent mold casting alloys, leaded yellow brass and its lead-free replacement EnviroBrass III, is not universally accepted due to the perceived problem of hard spots in finished castings and for the same reason these alloys contain very low amounts of iron. The yellow brasses and Cu-Si alloys are gaining popularity in North America due to their low lead content and amenability for permanent mold casting. These alloys are prone to hot tearing in permanent mold casting. Grain refinement is one of the solutions for reducing this problem. However, to use this technique it is necessary to understand the mechanism of grain refinement and other issues involved in the process. The following issues were studied during this three year project funded by the US Department of Energy and the copper casting industry: (1) Effect of alloying additions on the grain size of Cu-Zn alloys and their interaction with grain refiners; (2) Effect of two grain refining elements, boron and zirconium, on the grain size of four copper alloys, yellow brass, EnviroBrass II, silicon brass and silicon bronze and the duration of their effect (fading); (3) Prediction of grain refinement using cooling curve analysis and use of this method as an on-line quality control tool; (4) Hard spot formation in yellow brass and EnviroBrass due to grain refinement; (5) Corrosion resistance of the grain refined alloys; (6) Transfer the technology to permanent mold casting foundries; It was found that alloying elements such as tin and zinc do not change the grain size of Cu-Zn alloys

  5. Climate Change Adaptation | Department of Energy

    Energy Savers

    Climate Change Adaptation Climate Change Adaptation DOE is adapting to climate change by applying a risk-based resiliency approach to identify and minimize climate-related...

  6. AfricaAdapt | Open Energy Information

    Open Energy Information (Open El) [EERE & EIA]

    Africa Adapt AgencyCompany Organization AfricaAdapt Resource Type Training materials, Lessons learnedbest practices Website http:www.africa-adapt.netAA UN Region Eastern...

  7. Climate Adaptation for Transportation | Open Energy Information

    Open Energy Information (Open El) [EERE & EIA]

    Climate Adaptation for Transportation (Redirected from 03 Climate Adaptation for Transportation) Jump to: navigation, search Tool Summary LAUNCH TOOL Name: 03 Climate Adaptation...

  8. Parallel Finite Element Electron-Photon Transport Analysis on 2-D Unstructured Mesh

    SciTech Connect (OSTI)

    Drumm, C.R.

    1999-01-01

    A computer code has been developed to solve the linear Boltzmann transport equation on an unstructured mesh of triangles, from a Pro/E model. An arbitriwy arrangement of distinct material regions is allowed. Energy dependence is handled by solving over an arbitrary number of discrete energy groups. Angular de- pendence is treated by Legendre-polynomial expansion of the particle cross sections and a discrete ordinates treatment of the particle fluence. The resulting linear system is solved in parallel with a preconditioned conjugate-gradients method. The solution method is unique, in that the space-angle dependence is solved si- multaneously, eliminating the need for the usual inner iterations. Electron cross sections are obtained from a Goudsrnit-Saunderson modifed version of the CEPXS code. A one-dimensional version of the code has also been develop@ for testing and development purposes.

  9. Parallel FE Electron-Photon Transport Analysis on 2-D Unstructured Mesh

    SciTech Connect (OSTI)

    Drumm, C.R.; Lorenz, J.

    1999-03-02

    A novel solution method has been developed to solve the coupled electron-photon transport problem on an unstructured triangular mesh. Instead of tackling the first-order form of the linear Boltzmann equation, this approach is based on the second-order form in conjunction with the conventional multi-group discrete-ordinates approximation. The highly forward-peaked electron scattering is modeled with a multigroup Legendre expansion derived from the Goudsmit-Saunderson theory. The finite element method is used to treat the spatial dependence. The solution method is unique in that the space-direction dependence is solved simultaneously, eliminating the need for the conventional inner iterations, a method that is well suited for massively parallel computers.

  10. Advanced Mesh-Enabled Monte carlo capability for Multi-Physics Reactor Analysis

    SciTech Connect (OSTI)

    Wilson, Paul; Evans, Thomas; Tautges, Tim

    2012-12-24

    This project will accumulate high-precision fluxes throughout reactor geometry on a non- orthogonal grid of cells to support multi-physics coupling, in order to more accurately calculate parameters such as reactivity coefficients and to generate multi-group cross sections. This work will be based upon recent developments to incorporate advanced geometry and mesh capability in a modular Monte Carlo toolkit with computational science technology that is in use in related reactor simulation software development. Coupling this capability with production-scale Monte Carlo radiation transport codes can provide advanced and extensible test-beds for these developments. Continuous energy Monte Carlo methods are generally considered to be the most accurate computational tool for simulating radiation transport in complex geometries, particularly neutron transport in reactors. Nevertheless, there are several limitations for their use in reactor analysis. Most significantly, there is a trade-off between the fidelity of results in phase space, statistical accuracy, and the amount of computer time required for simulation. Consequently, to achieve an acceptable level of statistical convergence in high-fidelity results required for modern coupled multi-physics analysis, the required computer time makes Monte Carlo methods prohibitive for design iterations and detailed whole-core analysis. More subtly, the statistical uncertainty is typically not uniform throughout the domain, and the simulation quality is limited by the regions with the largest statistical uncertainty. In addition, the formulation of neutron scattering laws in continuous energy Monte Carlo methods makes it difficult to calculate adjoint neutron fluxes required to properly determine important reactivity parameters. Finally, most Monte Carlo codes available for reactor analysis have relied on orthogonal hexahedral grids for tallies that do not conform to the geometric boundaries and are thus generally not well

  11. Economic incentives for US refiners to process incremental domestic heavy crude oil

    SciTech Connect (OSTI)

    Guillermo, G.U.

    1995-12-31

    Faced with declining domestic crude supplies and increasing refined product demands, U.S. refiners devote a great deal of attention to securing alternate sources of crude oil. In addition to the traditional and cost-effective choice of imports, a potentially viable source is domestic heavy crude oil. Working with the U.S. Department of Energy and its contractor, the National Institute for Petroleum and Energy Research, Bonner & Moore undertook a project to ascertain the necessary adjustments U.S. refiners would need to make in order to process incremental amounts of heavy crude oil added to domestic refining slates between now and 2010. Results of this study indicated that significant economic investments would be required in order to process these crudes; processing of lighter imports, however, would remain substantially less costly. It would seem, then, that U.S. refiners would elect to process imports over incremental domestic heavy crudes unless they were offered some type of economic incentive to process the heavy oil. This paper addresses the issue of what those economic incentives could be.

  12. Need for refining capacity creates opportunities for producers in Middle East

    SciTech Connect (OSTI)

    Ali, M.S.S. )

    1994-07-11

    Oil industry interest in refining has revived in the past few years in response to rising oil consumption. The trend creates opportunities, for countries in the Middle East, which do not own refining assets nearly in proportion to their crude oil reserved. By closing this gap between reserves and refining capacity, the countries can ease some of the instability now characteristic of the oil market. Some major oil producing countries have begun to move downstream. During the 1980s, Venezuela, Kuwait, Saudi Arabia, Libya, and other members of the Organization of Petroleum Exporting Countries acquired refining assets through direct total purchase or joint ventures. Nevertheless, the oil industry remains largely unintegrated, with the Middle East holding two thirds of worldwide oil reserves but only a small share downstream. As worldwide refining capacity swings from a period of surplus toward one in which the need for new capacity will be built. The paper discusses background of the situation, shrinking surplus, investment requirements, sources of capital, and shipping concerns.

  13. Automated quadrilateral surface discretization method and apparatus usable to generate mesh in a finite element analysis system

    DOE Patents [OSTI]

    Blacker, Teddy D.

    1994-01-01

    An automatic quadrilateral surface discretization method and apparatus is provided for automatically discretizing a geometric region without decomposing the region. The automated quadrilateral surface discretization method and apparatus automatically generates a mesh of all quadrilateral elements which is particularly useful in finite element analysis. The generated mesh of all quadrilateral elements is boundary sensitive, orientation insensitive and has few irregular nodes on the boundary. A permanent boundary of the geometric region is input and rows are iteratively layered toward the interior of the geometric region. Also, an exterior permanent boundary and an interior permanent boundary for a geometric region may be input and the rows are iteratively layered inward from the exterior boundary in a first counter clockwise direction while the rows are iteratively layered from the interior permanent boundary toward the exterior of the region in a second clockwise direction. As a result, a high quality mesh for an arbitrary geometry may be generated with a technique that is robust and fast for complex geometric regions and extreme mesh gradations.

  14. Refining of fossil resin flotation concentrate from western coal. Final report

    SciTech Connect (OSTI)

    Jensen, G.F.; Miller, J.D.

    1995-02-16

    During the past several years, significant research efforts have been made to develop process technology for the selective flotation of fossil resin from western coals. As a result of these efforts, several new flotation technologies have been developed. Operation of a proof-of-concept continuous flotation circuit showed the selective flotation process to be sufficiently profitable to justify the development of a fossil resin industry. However, little attention has been given to the refining of the fossil resin flotation concentrate although solvent refining is a critical step for the fossil resin to become a marketable product. In view of this situation, DOE funded this two-year project to evaluate the following aspects of the fossil resin refining technology: 1) Characterization of the fossil resin flotation concentrate and its refined products; 2) Kinetics of fossil resin extraction; 3) Effects of operating variables on solvent extraction; 4) Extraction solvents; 5) Proof-of-concept continuous refining tests; and 6) Technical and economic analysis. The results from this research effort have led to the following conclusions: Hexane- or heptane-refined fossil resin has a light-yellow color, a melting point of 140 - 142{degrees}C, a density of 1.034 gram/cm, and good solubility in nonpolar solvents. Among the four solvents evaluated (hexane, heptane, toluene and ethyl acetate), hexane is the most appropriate solvent based on overall technical and economic considerations. Batch extraction tests and kinetic studies suggest that the main interaction between the resin and the solvent is expected to be the forces associated with solvation phenomena. Temperature has the most significant effect on extraction rate. With hexane as the solvent, a recovery of 90% cam be achieved at 50{degrees}C and 10% solids concentration with moderate agitation for 1 hour.

  15. Free kick instead of cross-validation in maximum-likelihood refinement of macromolecular crystal structures

    SciTech Connect (OSTI)

    Pranikar, Jure [Institute Joef Stefan, Jamova 39, 1000 Ljubljana (Slovenia); University of Primorska, (Slovenia); Turk, Duan, E-mail: dusan.turk@ijs.si [Institute Joef Stefan, Jamova 39, 1000 Ljubljana (Slovenia); Center of Excellence for Integrated Approaches in Chemistry and Biology of Proteins, (Slovenia)

    2014-12-01

    The maximum-likelihood free-kick target, which calculates model error estimates from the work set and a randomly displaced model, proved superior in the accuracy and consistency of refinement of crystal structures compared with the maximum-likelihood cross-validation target, which calculates error estimates from the test set and the unperturbed model. The refinement of a molecular model is a computational procedure by which the atomic model is fitted to the diffraction data. The commonly used target in the refinement of macromolecular structures is the maximum-likelihood (ML) function, which relies on the assessment of model errors. The current ML functions rely on cross-validation. They utilize phase-error estimates that are calculated from a small fraction of diffraction data, called the test set, that are not used to fit the model. An approach has been developed that uses the work set to calculate the phase-error estimates in the ML refinement from simulating the model errors via the random displacement of atomic coordinates. It is called ML free-kick refinement as it uses the ML formulation of the target function and is based on the idea of freeing the model from the model bias imposed by the chemical energy restraints used in refinement. This approach for the calculation of error estimates is superior to the cross-validation approach: it reduces the phase error and increases the accuracy of molecular models, is more robust, provides clearer maps and may use a smaller portion of data for the test set for the calculation of R{sub free} or may leave it out completely.

  16. New Seismic Model Will Refine Hazard Analysis at U.S. Nuclear Plants |

    Office of Energy Efficiency and Renewable Energy (EERE) (indexed site)

    Department of Energy Seismic Model Will Refine Hazard Analysis at U.S. Nuclear Plants New Seismic Model Will Refine Hazard Analysis at U.S. Nuclear Plants January 31, 2012 - 2:09pm Addthis The Electric Power Research Institute (EPRI), the U.S. Department of Energy (DOE), and the U.S. Nuclear Regulatory Commission (NRC) released a new seismic study today that will help U.S. nuclear facilities in the central and eastern United States reassess seismic hazards. The Central and Eastern United

  17. Appendices: Steam System Opportunity Assessment for the Pulp and Paper, Chemical Manufacturing, and Petroleum Refining Industries

    Office of Energy Efficiency and Renewable Energy (EERE) (indexed site)

    DE P A R T M E N U E N I T E D S T A T S O F A E R IC A M Office of Energy Efficency and Renewable Energy U.S. Department of Energy Steam System Opportunity Assessment for the Pulp and Paper, Chemical Manufacturing, and Petroleum Refining Industries Steam System Opportunity Assessment for the Pulp and Paper, Chemical Manufacturing, and Petroleum Refining Industries Appendices Appendices (This page intentionally left blank.) Steam System Opportunity Assessment for the Pulp and Paper, Chemical

  18. ,"U.S. Aviation Gasoline Refiner Sales Volumes"

    U.S. Energy Information Administration (EIA) (indexed site)

    Aviation Gasoline Refiner Sales Volumes" ,"Click worksheet name or tab at bottom for data" ,"Worksheet Name","Description","# Of Series","Frequency","Latest Data for" ,"Data 1","U.S. Aviation Gasoline Refiner Sales Volumes",2,"Monthly","8/2016","1/15/1983" ,"Release Date:","11/1/2016" ,"Next Release Date:","12/1/2016" ,"Excel File

  19. ,"U.S. Residual Fuel Oil Refiner Sales Volumes"

    U.S. Energy Information Administration (EIA) (indexed site)

    Refiner Sales Volumes" ,"Click worksheet name or tab at bottom for data" ,"Worksheet Name","Description","# Of Series","Frequency","Latest Data for" ,"Data 1","U.S. Residual Fuel Oil Refiner Sales Volumes",2,"Monthly","8/2016","1/15/1983" ,"Release Date:","11/1/2016" ,"Next Release Date:","12/1/2016" ,"Excel File

  20. ,"U.S. Total Refiner Acquisition Cost of Crude Oil"

    U.S. Energy Information Administration (EIA) (indexed site)

    Refiner Acquisition Cost of Crude Oil" ,"Click worksheet name or tab at bottom for data" ,"Worksheet Name","Description","# Of Series","Frequency","Latest Data for" ,"Data 1","U.S. Total Refiner Acquisition Cost of Crude Oil",3,"Annual",2015,"6/30/1968" ,"Release Date:","11/1/2016" ,"Next Release Date:","12/1/2016" ,"Excel File

  1. Toward reflexive climate adaptation research

    DOE PAGES-Beta [OSTI]

    Preston, Benjamin L.; Rickards, Lauren; Fünfgeld, Hartmut; Keenan, Rodney J.

    2015-06-22

    Climate adaptation research is expanding very quickly within an increasingly reflexive society where the relationship between academia and other social institutions is in a state of flux. Tensions exist between the two dominant research orientations of research about and research for adaptation. In particular, the research community is challenged to develop processes for successfully executing transdisciplinary research for adaptation when academic institutions and researchers are largely structured around traditional, disciplinary expertise and funding models. One tool for helping to manage this tension is a third, more reflexive, orientation toward adaptation research that is emerging in the literature. Finally, this newmore » ‘research on adaptation research’ promises to help enhance understanding of the research enterprise itself and how it can become more adaptive.« less

  2. Toward reflexive climate adaptation research

    SciTech Connect (OSTI)

    Preston, Benjamin L.; Rickards, Lauren; Fünfgeld, Hartmut; Keenan, Rodney J.

    2015-06-22

    Climate adaptation research is expanding very quickly within an increasingly reflexive society where the relationship between academia and other social institutions is in a state of flux. Tensions exist between the two dominant research orientations of research about and research for adaptation. In particular, the research community is challenged to develop processes for successfully executing transdisciplinary research for adaptation when academic institutions and researchers are largely structured around traditional, disciplinary expertise and funding models. One tool for helping to manage this tension is a third, more reflexive, orientation toward adaptation research that is emerging in the literature. Finally, this new ‘research on adaptation research’ promises to help enhance understanding of the research enterprise itself and how it can become more adaptive.

  3. Adaptive capacity and its assessment

    SciTech Connect (OSTI)

    Engle, Nathan L.

    2011-04-20

    This paper reviews the concept of adaptive capacity and various approaches to assessing it, particularly with respect to climate variability and change. I find that adaptive capacity is a relatively under-researched topic within the sustainability science and global change communities, particularly since it is uniquely positioned to improve linkages between vulnerability and resilience research. I identify opportunities for advancing the measurement and characterization of adaptive capacity by combining insights from both vulnerability and resilience frameworks, and I suggest several assessment approaches for possible future development that draw from both frameworks and focus on analyzing the governance, institutions, and management that have helped foster adaptive capacity in light of recent climatic events.

  4. RAZAR Adaptive Zoom Rifle Scope

    SciTech Connect (OSTI)

    Bagwell, Brett; Baker, Mike; Heinsohn, John; Squire, Michael

    2014-10-22

    RAZAR adaptive zoom is a revolutionary method whereby true optical zoom is accomplished by cooperatively varying the focal lengths of multiple active optical elements in the system.

  5. Studies on design of a process for organo-refining of coal to obtain super clean coal

    SciTech Connect (OSTI)

    Sharma, C.S.; Sharma, D.K.

    1999-08-01

    Organo-refining of coal results in refining the coal to obtain super clean coal and residual coal. Super clean coal may be used to obtain value added chemicals, products, and cleaner fuels from coal. In the present work, studies on the design of a semicontinuous process for organo-refining of one ton of coal have been made. The results are reported. This is only a cursory attempt for the design, and further studies may be required for designing this process for use in the development of a scaled-up process of organo-refining of coal.

  6. A massively parallel adaptive finite element method with dynamic load balancing

    SciTech Connect (OSTI)

    Devine, K.D.; Flaherty, J.E.; Wheat, S.R.; Maccabe, A.B.

    1993-12-31

    The authors construct massively parallel adaptive finite element methods for the solution of hyperbolic conservation laws. Spatial discretization is performed by a discontinuous Galerkin finite element method using a basis of piecewise Legendre polynomials. Temporal discretization utilizes a Runge-Kutta method. Dissipative fluxes and projection limiting prevent oscillations near solution discontinuities. The resulting method is of high order and may be parallelized efficiently on MIMD computers. They demonstrate parallel efficiency through computations on a 1024-processor nCUBE/2 hypercube. They present results using adaptive p-refinement to reduce the computational cost of the method, and tiling, a dynamic, element-based data migration system that maintains global load balance of the adaptive method by overlapping neighborhoods of processors that each perform local balancing.

  7. Rocky Mountain area petroleum product availability with reduced PADD IV refining capacity

    SciTech Connect (OSTI)

    Hadder, G.R.; Chin, S.M.

    1994-02-01

    Studies of Rocky Mountain area petroleum product availability with reduced refining capacity in Petroleum Administration for Defense IV (PADD IV, part of the Rocky Mountain area) have been performed with the Oak Ridge National Laboratory Refinery Yield Model, a linear program which has been updated to blend gasolines to satisfy constraints on emissions of nitrogen oxides and winter toxic air pollutants. The studies do not predict refinery closures in PADD IV. Rather, the reduced refining capacities provide an analytical framework for probing the flexibility of petroleum refining and distribution for winter demand conditions in the year 2000. Industry analysts have estimated that, for worst case scenarios, 20 to 35 percent of PADD IV refining capacity could be shut-down as a result of clean air and energy tax legislation. Given these industry projections, the study scenarios provide the following conclusions: The Rocky Mountain area petroleum system would have the capability to satisfy winter product demand with PADD IV refinery capacity shut-downs in the middle of the range of industry projections, but not in the high end of the range of projections. PADD IV crude oil production can be maintained by re-routing crude released from PADD IV refinery demands to satisfy increased crude oil demands in PADDs II (Midwest), III (Gulf Coast), and Washington. Clean Air Act product quality regulations generally do not increase the difficulty of satisfying emissions reduction constraints in the scenarios.

  8. Environmental Regulations and Changes in Petroleum Refining Operations (Released in the STEO June 1998)

    Reports and Publications

    1998-01-01

    Changes in domestic refining operations are identified and related to the summer Reid vapor pressure (RVP) restrictions and oxygenate blending requirements. This analysis uses published Energy Information Administration survey data and linear regression equations from the Short-Term Integrated Forecasting System (STIFS). The STIFS model is used for producing forecasts appearing in the Short-Term Energy Outlook.

  9. Table A1. Refiner/Reseller Motor Gasoline Prices by Grade, PAD...

    U.S. Energy Information Administration (EIA) (indexed site)

    71.6 92.3 78.2 101.8 83.6 87.5 74.7 See footnotes at end of table. A1. RefinerReseller Motor Gasoline Prices by Grade, PAD District, and State, 1984-Present 452 Energy Information...

  10. Table 6. U.S. Refiner Motor Gasoline Prices by Grade and Sales...

    U.S. Energy Information Administration (EIA) (indexed site)

    61.5 67.3 89.8 89.5 82.2 69.4 71.1 74.9 See footnotes at end of table. 6. U.S. Refiner Motor Gasoline Prices by Grade and Sales Type 12 Energy Information Administration ...

  11. Table 7. U.S. Refiner Motor Gasoline Volumes by Grade and Sales...

    U.S. Energy Information Administration (EIA) (indexed site)

    35.2 213.6 9.5 9.8 12.9 16.6 NA 29.5 See footnotes at end of table. 7. U.S. Refiner Motor Gasoline Volumes by Grade and Sales Type 14 Energy Information Administration ...

  12. Table 11. U.S. Refiner Oxygenated Motor Gasoline Volumes by...

    U.S. Energy Information Administration (EIA) (indexed site)

    W 5.6 0.5 0.5 0.5 0.4 - 0.9 See footnotes at end of table. 11. U.S. Refiner Oxygenated Motor Gasoline Volumes by Grade and Sales Type 22 Energy Information Administration ...

  13. Table 6. U.S. Refiner Motor Gasoline Prices by Grade and Sales...

    U.S. Energy Information Administration (EIA) (indexed site)

    62.2 68.5 90.1 89.6 82.4 70.9 NA 75.9 See footnotes at end of table. 6. U.S. Refiner Motor Gasoline Prices by Grade and Sales Type 12 Energy Information Administration ...

  14. Table 7. U.S. Refiner Motor Gasoline Volumes by Grade and Sales...

    U.S. Energy Information Administration (EIA) (indexed site)

    33.9 215.8 9.7 10.0 12.1 16.3 0.0 28.4 See footnotes at end of table. 7. U.S. Refiner Motor Gasoline Volumes by Grade and Sales Type 14 Energy Information Administration ...

  15. Table 11. U.S. Refiner Oxygenated Motor Gasoline Volumes by...

    U.S. Energy Information Administration (EIA) (indexed site)

    - 4.9 0.4 0.4 0.3 0.4 - 0.7 See footnotes at end of table. 11. U.S. Refiner Oxygenated Motor Gasoline Volumes by Grade and Sales Type 22 Energy Information Administration ...

  16. Towards solution and refinement of organic crystal structures by fitting to the atomic pair distribution function

    DOE PAGES-Beta [OSTI]

    Prill, Dragica; Juhas, Pavol; Billinge, Simon J. L.; Schmidt, Martin U.

    2016-01-01

    In this study, a method towards the solution and refinement of organic crystal structures by fitting to the atomic pair distribution function (PDF) is developed. Approximate lattice parameters and molecular geometry must be given as input. The molecule is generally treated as a rigid body. The positions and orientations of the molecules inside the unit cell are optimized starting from random values. The PDF is obtained from carefully measured X-ray powder diffraction data. The method resembles `real-space' methods for structure solution from powder data, but works with PDF data instead of the diffraction pattern itself. As such it may bemore » used in situations where the organic compounds are not long-range-ordered, are poorly crystalline, or nanocrystalline. The procedure was applied to solve and refine the crystal structures of quinacridone (β phase), naphthalene and allopurinol. In the case of allopurinol it was even possible to successfully solve and refine the structure in P1 with four independent molecules. As an example of a flexible molecule, the crystal structure of paracetamol was refined using restraints for bond lengths, bond angles and selected torsion angles. In all cases, the resulting structures are in excellent agreement with structures from single-crystal data.« less

  17. Tools for macromolecular model building and refinement into electron cryo-microscopy reconstructions

    SciTech Connect (OSTI)

    Brown, Alan; Long, Fei; Nicholls, Robert A.; Toots, Jaan; Emsley, Paul; Murshudov, Garib

    2015-01-01

    A description is given of new tools to facilitate model building and refinement into electron cryo-microscopy reconstructions. The recent rapid development of single-particle electron cryo-microscopy (cryo-EM) now allows structures to be solved by this method at resolutions close to 3 Å. Here, a number of tools to facilitate the interpretation of EM reconstructions with stereochemically reasonable all-atom models are described. The BALBES database has been repurposed as a tool for identifying protein folds from density maps. Modifications to Coot, including new Jiggle Fit and morphing tools and improved handling of nucleic acids, enhance its functionality for interpreting EM maps. REFMAC has been modified for optimal fitting of atomic models into EM maps. As external structural information can enhance the reliability of the derived atomic models, stabilize refinement and reduce overfitting, ProSMART has been extended to generate interatomic distance restraints from nucleic acid reference structures, and a new tool, LIBG, has been developed to generate nucleic acid base-pair and parallel-plane restraints. Furthermore, restraint generation has been integrated with visualization and editing in Coot, and these restraints have been applied to both real-space refinement in Coot and reciprocal-space refinement in REFMAC.

  18. EIS-0069: Solvent Refined Coal-II Demonstration Project, Fort Martin, Monongalia County, West Virginia

    Energy.gov [DOE]

    The U.S. Department of Energy developed this statement to assess the potential environmental, economic and social impacts associated with the construction and short-term operation of a 6,000-tons-per-stream-day-capacity facility that will demonstrate the technical operability, economic viability, and environmental acceptability of the solvent refined coal process at Fort Martin, West Virginia.

  19. Towards solution and refinement of organic crystal structures by fitting to the atomic pair distribution function

    SciTech Connect (OSTI)

    Prill, Dragica; Juhas, Pavol; Billinge, Simon J. L.; Schmidt, Martin U.

    2016-01-01

    In this study, a method towards the solution and refinement of organic crystal structures by fitting to the atomic pair distribution function (PDF) is developed. Approximate lattice parameters and molecular geometry must be given as input. The molecule is generally treated as a rigid body. The positions and orientations of the molecules inside the unit cell are optimized starting from random values. The PDF is obtained from carefully measured X-ray powder diffraction data. The method resembles `real-space' methods for structure solution from powder data, but works with PDF data instead of the diffraction pattern itself. As such it may be used in situations where the organic compounds are not long-range-ordered, are poorly crystalline, or nanocrystalline. The procedure was applied to solve and refine the crystal structures of quinacridone (β phase), naphthalene and allopurinol. In the case of allopurinol it was even possible to successfully solve and refine the structure in P1 with four independent molecules. As an example of a flexible molecule, the crystal structure of paracetamol was refined using restraints for bond lengths, bond angles and selected torsion angles. In all cases, the resulting structures are in excellent agreement with structures from single-crystal data.

  20. Exploiting structure similarity in refinement: automated NCS and target-structure restraints in BUSTER

    SciTech Connect (OSTI)

    Smart, Oliver S. Womack, Thomas O.; Flensburg, Claus; Keller, Peter; Paciorek, Włodek; Sharff, Andrew; Vonrhein, Clemens; Bricogne, Gérard

    2012-04-01

    Local structural similarity restraints (LSSR) provide a novel method for exploiting NCS or structural similarity to an external target structure. Two examples are given where BUSTER re-refinement of PDB entries with LSSR produces marked improvements, enabling further structural features to be modelled. Maximum-likelihood X-ray macromolecular structure refinement in BUSTER has been extended with restraints facilitating the exploitation of structural similarity. The similarity can be between two or more chains within the structure being refined, thus favouring NCS, or to a distinct ‘target’ structure that remains fixed during refinement. The local structural similarity restraints (LSSR) approach considers all distances less than 5.5 Å between pairs of atoms in the chain to be restrained. For each, the difference from the distance between the corresponding atoms in the related chain is found. LSSR applies a restraint penalty on each difference. A functional form that reaches a plateau for large differences is used to avoid the restraints distorting parts of the structure that are not similar. Because LSSR are local, there is no need to separate out domains. Some restraint pruning is still necessary, but this has been automated. LSSR have been available to academic users of BUSTER since 2009 with the easy-to-use -autoncs and @@target target.pdb options. The use of LSSR is illustrated in the re-refinement of PDB entries http://scripts.iucr.org/cgi-bin/cr.cgi?rm, where -target enables the correct ligand-binding structure to be found, and http://scripts.iucr.org/cgi-bin/cr.cgi?rm, where -autoncs contributes to the location of an additional copy of the cyclic peptide ligand.

  1. Enhanced retained dose uniformity in NiTi spinal correction rod treated by three-dimensional mesh-assisted nitrogen plasma immersion ion implantation

    SciTech Connect (OSTI)

    Lu, Q. Y.; Hu, T.; Kwok, Dixon T. K.; Chu, Paul K.

    2010-05-15

    Owing to the nonconformal plasma sheath in plasma immersion ion implantation of a rod sample, the retained dose can vary significantly. The authors propose to improve the implant uniformity by introducing a metal mesh. The depth profiles obtained with and without the mesh are compared and the implantation temperature at various locations is evaluated indirectly by differential scanning calorimeter. Our results reveal that by using the metal mesh, the retained dose uniformity along the length is greatly improved and the effects of the implantation temperature on the localized mechanical properties of the implanted NiTi shape memory alloy rod are nearly negligible.

  2. WENO schemes on arbitrary unstructured meshes for laminar, transitional and turbulent flows

    SciTech Connect (OSTI)

    Tsoutsanis, Panagiotis, E-mail: panagiotis.tsoutsanis@cranfield.ac.uk; Antoniadis, Antonios Foivos, E-mail: a.f.antoniadis@cranfield.ac.uk; Drikakis, Dimitris, E-mail: d.drikakis@cranfield.ac.uk

    2014-01-01

    This paper presents the development and implementation of weighted-essentially-non-oscillatory (WENO) schemes for viscous flows on arbitrary unstructured grids. WENO schemes up to fifth-order accurate have been implemented in conjunction with hybrid and non-hybrid unstructured grids. The schemes are investigated with reference to numerical and experimental results for the TaylorGreen vortex, as well as for laminar and turbulent flows around a sphere, and the turbulent shock-wave boundary layer interaction flow problem. The results show that the accuracy of the schemes depends on the arbitrariness of shape and orientation of the unstructured mesh elements, as well as the compactness of directional stencils. The WENO schemes provide a more accurate numerical framework compared to second-order and third-order total variation diminishing (TVD) methods, however, the fifth-order version of the schemes is computationally too expensive to make the schemes practically usable. On the other hand, the third-order variant offers an excellent numerical framework in terms of accuracy and computational cost compared to the fifth-order WENO and second-order TVD schemes. Parallelisation of the CFD code (henceforth labelled as UCNS3D), where the schemes have been implemented, shows that the present methods offer very good scalable performance.

  3. Generalized Framework and Algorithms for Illustrative Visualization of Time-Varying Data on Unstructured Meshes

    SciTech Connect (OSTI)

    Alexander S. Rattner; Donna Post Guillen; Alark Joshi

    2012-12-01

    Photo- and physically-realistic techniques are often insufficient for visualization of simulation results, especially for 3D and time-varying datasets. Substantial research efforts have been dedicated to the development of non-photorealistic and illustration-inspired visualization techniques for compact and intuitive presentation of such complex datasets. While these efforts have yielded valuable visualization results, a great deal of work has been reproduced in studies as individual research groups often develop purpose-built platforms. Additionally, interoperability between illustrative visualization software is limited due to specialized processing and rendering architectures employed in different studies. In this investigation, a generalized framework for illustrative visualization is proposed, and implemented in marmotViz, a ParaView plugin, enabling its use on variety of computing platforms with various data file formats and mesh geometries. Detailed descriptions of the region-of-interest identification and feature-tracking algorithms incorporated into this tool are provided. Additionally, implementations of multiple illustrative effect algorithms are presented to demonstrate the use and flexibility of this framework. By providing a framework and useful underlying functionality, the marmotViz tool can act as a springboard for future research in the field of illustrative visualization.

  4. Framework and algorithms for illustrative visualizations of time-varying flows on unstructured meshes

    DOE PAGES-Beta [OSTI]

    Rattner, Alexander S.; Guillen, Donna Post; Joshi, Alark; Garimella, Srinivas

    2016-03-17

    Photo- and physically realistic techniques are often insufficient for visualization of fluid flow simulations, especially for 3D and time-varying studies. Substantial research effort has been dedicated to the development of non-photorealistic and illustration-inspired visualization techniques for compact and intuitive presentation of such complex datasets. However, a great deal of work has been reproduced in this field, as many research groups have developed specialized visualization software. Additionally, interoperability between illustrative visualization software is limited due to diverse processing and rendering architectures employed in different studies. In this investigation, a framework for illustrative visualization is proposed, and implemented in MarmotViz, a ParaViewmore » plug-in, enabling its use on a variety of computing platforms with various data file formats and mesh geometries. Region-of-interest identification and feature-tracking algorithms incorporated into this tool are described. Implementations of multiple illustrative effect algorithms are also presented to demonstrate the use and flexibility of this framework. Here, by providing an integrated framework for illustrative visualization of CFD data, MarmotViz can serve as a valuable asset for the interpretation of simulations of ever-growing scale.« less

  5. Adaptive multiconfigurational wave functions

    SciTech Connect (OSTI)

    Evangelista, Francesco A.

    2014-03-28

    A method is suggested to build simple multiconfigurational wave functions specified uniquely by an energy cutoff ?. These are constructed from a model space containing determinants with energy relative to that of the most stable determinant no greater than ?. The resulting ?-CI wave function is adaptive, being able to represent both single-reference and multireference electronic states. We also consider a more compact wave function parameterization (?+SD-CI), which is based on a small ?-CI reference and adds a selection of all the singly and doubly excited determinants generated from it. We report two heuristic algorithms to build ?-CI wave functions. The first is based on an approximate prescreening of the full configuration interaction space, while the second performs a breadth-first search coupled with pruning. The ?-CI and ?+SD-CI approaches are used to compute the dissociation curve of N{sub 2} and the potential energy curves for the first three singlet states of C{sub 2}. Special attention is paid to the issue of energy discontinuities caused by changes in the size of the ?-CI wave function along the potential energy curve. This problem is shown to be solvable by smoothing the matrix elements of the Hamiltonian. Our last example, involving the Cu{sub 2}O{sub 2}{sup 2+} core, illustrates an alternative use of the ?-CI method: as a tool to both estimate the multireference character of a wave function and to create a compact model space to be used in subsequent high-level multireference coupled cluster computations.

  6. Magnesium Recycling of Partially Oxidized, Mixed Magnesium-Aluminum Scrap Through Combined Refining and Solid Oxide Membrane (SOM) Electrolysis Processes

    SciTech Connect (OSTI)

    Guan, Xiaofei; Zink, Peter; Pal, Uday

    2012-03-11

    Pure magnesium (Mg) is recycled from 19g of partially oxidized 50.5wt.%Mg-Aluminum (Al) alloy. During the refining process, potentiodynamic scans (PDS) were performed to determine the electrorefining potential for magnesium. The PDS show that the electrorefining potential increases over time as the Mg content inside the Mg-Al scrap decreases. Up to 100% percent of magnesium is refined from the Mg-Al scrap by a novel refining process of dissolving magnesium and its oxide into a flux followed by vapor phase removal of dissolved magnesium and subsequently condensing the magnesium vapors in a separate condenser. The solid oxide membrane (SOM) electrolysis process is employed in the refining system to enable additional recycling of magnesium from magnesium oxide (MgO) in the partially oxidized Mg-Al scrap. The combination of the refining and SOM processes yields 7.4g of pure magnesium; could not collect and weigh all of the magnesium recovered.

  7. Magnesium Recycling of Partially Oxidized, Mixed Magnesium-Aluminum Scrap through Combined Refining and Solid Oxide Membrane Electrolysis Processes

    SciTech Connect (OSTI)

    Xiaofei Guan; Peter A. Zink; Uday B. Pal; Adam C. Powell

    2012-01-01

    Pure magnesium (Mg) is recycled from 19g of partially oxidized 50.5wt.% Mg-Aluminum (Al) alloy. During the refining process, potentiodynamic scans (PDS) were performed to determine the electrorefining potential for magnesium. The PDS show that the electrorefining potential increases over time as the magnesium content inside the Mg-Al scrap decreases. Up to 100% percent of magnesium is refined from the Mg-Al scrap by a novel refining process of dissolving magnesium and its oxide into a flux followed by vapor phase removal of dissolved magnesium and subsequently condensing the magnesium vapor. The solid oxide membrane (SOM) electrolysis process is employed in the refining system to enable additional recycling of magnesium from magnesium oxide (MgO) in the partially oxidized Mg-Al scrap. The combination of the refining and SOM processes yields 7.4g of pure magnesium.

  8. REE Sorption Study of Seived -50 +100 Mesh Fraction of Media #1 in Brine #1 at Different Concentrations of REE at 70C

    SciTech Connect (OSTI)

    Gary Garland

    2015-06-29

    This dataset shows the sorption capacities of smaller grain size (-50 +100 mesh) of media #1 in brine #1 at different starting concentrations of REE's at elevated temperature of 70C. The experimental conditions are 2g of -50 +100 mesh media #1 to 150mL of REE solution at concentartions of .2ppm each, 2ppm each, and 20ppm each. The pH of the solution is 5.5, and the temperature was at 70C.

  9. Profiling of selenium removal in hydrogen ambient zone-refined tellurium bar using RF-GDOES

    SciTech Connect (OSTI)

    Anil, G. . E-mail: anilpillai_99@yahoo.com; Reddy, M.R.P.; Prasad, D.S.; Ali, S.T.; Munirathnam, N.R.; Prakash, T.L.

    2007-01-15

    Ultrapure tellurium (Te) metal has become an important metal in the strategic sector for fabricating high performance infrared devices for thermal imaging and night vision cameras. Zone refining (ZR) is a proven technique for purification of Te. Selenium (Se), present as an impurity in Te, is not easily removed by ZR under normal conditions as the segregation coefficient (K) is around 0.44-0.50. Hence, ZR was performed in a hydrogen atmosphere, during which Se gets converted to hydrogen selenide at the molten moving zones and carried away into the sodium hydroxide scrubbers. In this study a radio-frequency glow discharge optical emission spectrometer (RF-GDOES) was used for determining the concentration of Se along the 56 cm Te zone-refined bar. It was observed that the initial concentration of 1100 ppb Se was decreased to 30 ppb after 2 cycles.

  10. The effects of air pollution regulations on the US refining industry. Task 3

    SciTech Connect (OSTI)

    Not Available

    1989-06-01

    Numerous air pollution regulations affecting petroleum refineries recently have been promulgated, have been proposed, or are under consideration at the federal, state, and local level. As shown in Figure ES-1, all of these environmental regulations are intended to take effect over the relatively short time period from 1989 through 1995. In the aggregate these regulatory activities have significant implications for the US refining industry and the Nation, including: Major investment requirements; changes in industry profitability; potential closure of some refineries; and potential changes in crude oil or product import dependence. At issue is whether the cumulative effect of these regulations could so adversely affect the US refining industry that US national security would be affected. In addition to the regulations outlined in Figure ES-1, President Bush recently presented a major new plan to improve the nation`s air quality. The aspects of the President`s plan that could strongly affect US refineries are summarized below.

  11. Report to the Congress on the storage of refined petroleum products and on regional supply interruptions

    SciTech Connect (OSTI)

    Not Available

    1991-06-01

    This report describes petroleum and petroleum products storage and supply disruption. Information is presented under the following topics: Historical Perspective; Current Patterns of Supply and Disposition of Petroleum Products in the Primary Distribution System; PADD I Clean Products Supply/Demand; 1990 Regional Petroleum Reserve Annual Computation; Market Infrastructure and Commercial Practices in the California Motor Gasoline Market, as Related to Potential Refined Petroleum Product Reserve Structures and Sales Procedures; Infrastructure and Commercial Practices in the Northeast Distillate Market, as Related to Potential Refined Petroleum Product Reserve Structures and Sales Procedures; Storage Stability Characteristics of Petroleum Products and Crude Oil; Effect of 1990 Clean Air Act Amendments on Demand for Petroleum Product Storage Capacity; and Environmental Regulations on Tanks.

  12. COMMENTARY:Limits to adaptation

    SciTech Connect (OSTI)

    Preston, Benjamin L

    2013-01-01

    An actor-centered, risk-based approach to defining limits to social adaptation provides a useful analytic framing for identifying and anticipating these limits and informing debates over society s responses to climate change.

  13. ACCO Climate Change Adaptation Workshop

    Office of Energy Efficiency and Renewable Energy (EERE)

    The Association of Climate Change Officers (ACCO) is hosting a two-day training workshop titled, "Climate Change Adaptation" to cover climate science, impacts from severe climate events, tools to screen and access vulnerabilities, and strategies to lead organizational change.

  14. Parametric Adaptive Model Based Diagnostics

    Energy.gov [DOE]

    A model-based adaptive, robust technology is presented for on-board diagnostics of failure of diesel engine emission control devices and ethanol estimation of flex-fuel vehicles.

  15. 2014 DOE Climate Change Adaptation Plan

    Office of Energy Efficiency and Renewable Energy (EERE) (indexed site)

    4 U.S. Department of Energy June 2014 DOE Climate Change Adaptation Plan Table of Contents Climate Change Adaptation Plan ................................................................................................................................2 Impetus for Action ..................................................................................................................................................2 The DOE Mission and Climate Change Adaptation

  16. Implications of Increasing Light Tight Oil Production for U.S. Refining -

    U.S. Energy Information Administration (EIA) (indexed site)

    Energy Information Administration Implications of Increasing Light Tight Oil Production for U.S. Refining Release date: May 5, 2015 Revised: May 12, 2015 (revision) 1. Background and Analytical Framework Background Recent and projected increases in U.S. crude production have sparked discussion about the implications of current limitations on crude oil exports for prices, including both world and domestic crude oil and petroleum product prices, and for the level of domestic crude production

  17. Grain refinement of cast zinc through magnesium inoculation: Characterisation and mechanism

    SciTech Connect (OSTI)

    Liu, Zhilin; Qiu, Dong; Wang, Feng; Taylor, John A.; Zhang, Mingxing

    2015-08-15

    It was previously found that peritectic-forming solutes are more favourable for the grain refinement of cast Al alloys than eutectic-forming solutes. In this work, we report that the eutectic-forming solute, Mg, can also significantly grain refine cast Zn. Differential thermal analysis (DTA) of a Zn–Mg alloy, in which efficient grain refinement occurred, evidenced an unexpected peak that appeared before the nucleation of η-Zn grains on the DTA spectrum. Based on extensive examination using X-ray diffraction, high resolution SEM and EDS, it was found that: (a) some faceted Zn–Mg intermetallic particles were reproducibly observed; (b) the particles were located at or near grain centres; (c) the atomic ratio of Mg to Zn in the intermetallic compound was determined to be around 1/2. Using tilting selected area diffraction (SAD) and convergent beam Kikuchi line diffraction pattern (CBKLDP) techniques, these faceted particles were identified as MgZn{sub 2} and an orientation relationship between such grain-centred MgZn{sub 2} particles and the η-Zn matrix was determined. Hence, the unexpected peak on the DTA spectrum is believed to correspond to the formation of MgZn{sub 2} particles, which act as effective heterogeneous nucleation sites in the alloy. Together with the effect of Mg solute on restricting grain growth, such heterogeneous nucleation is cooperatively responsible for the grain size reduction in Zn–Mg alloys. - Highlights: • A new eutectic-based grain refiner for the cast Zn was found. • The formation process of an intermetallic compound (MgZn{sub 2}) was characterised. • MgZn{sub 2} can act as potent heterogeneous nucleation sites above the liquidus. • A new OR between MgZn{sub 2} and η-Zn was determined using the CBKLDP technique.

  18. Application of a catalyst deactivation model for hydrotreating solvent refined coal feedstocks

    SciTech Connect (OSTI)

    Nalitham, R.V.

    1983-10-01

    A simple kinetic model, including a first-order catalyst deactivation rate, is applied to upgrading of coal-derived feedstocks prepared from two solvent refined coal fractions. A catalyst deactivation mechanism is proposed which involves the adsorption and surface reaction of coke precursors on catalytic active sites. The effect of feedstock composition, temperature and pressure on kinetic parameters, and in particular the catalyst deactivation rate, is determined.

  19. NREL Refines Method to Convert Lignin to Nylon Precursor - News Releases |

    U.S. Department of Energy (DOE) all webpages (Extended Search)

    NREL NREL Refines Method to Convert Lignin to Nylon Precursor Recent Findings Published in Energy & Environmental Science February 26, 2015 A new study from the Energy Department's National Renewable Energy Laboratory (NREL) demonstrates the conversion of lignin-derived compounds to adipic acid, an important industrial dicarboxylic acid produced for its use as a precursor to nylon, plasticizers, lubricants, polyesters, and other popular products and chemicals. The demonstration is an

  20. Refined BCF-type boundary conditions for mesoscale surface step dynamics

    DOE PAGES-Beta [OSTI]

    Zhao, Renjie; Ackerman, David M.; Evans, James W.

    2015-06-24

    Deposition on a vicinal surface with alternating rough and smooth steps is described by a solid-on-solid model with anisotropic interactions. Kinetic Monte Carlo (KMC) simulations of the model reveal step pairing in the absence of any additional step attachment barriers. We explore the description of this behavior within an analytic Burton-Cabrera-Frank (BCF)-type step dynamics treatment. Without attachment barriers, conventional kinetic coefficients for the rough and smooth steps are identical, as are the predicted step velocities for a vicinal surface with equal terrace widths. However, we determine refined kinetic coefficients from a two-dimensional discrete deposition-diffusion equation formalism which accounts for stepmore » structure. These coefficients are generally higher for rough steps than for smooth steps, reflecting a higher propensity for capture of diffusing terrace adatoms due to a higher kink density. Such refined coefficients also depend on the local environment of the step and can even become negative (corresponding to net detachment despite an excess adatom density) for a smooth step in close proximity to a rough step. Incorporation of these refined kinetic coefficients into a BCF-type step dynamics treatment recovers quantitatively the mesoscale step-pairing behavior observed in the KMC simulations.« less

  1. Refined BCF-type boundary conditions for mesoscale surface step dynamics

    SciTech Connect (OSTI)

    Zhao, Renjie; Ackerman, David M.; Evans, James W.

    2015-06-24

    Deposition on a vicinal surface with alternating rough and smooth steps is described by a solid-on-solid model with anisotropic interactions. Kinetic Monte Carlo (KMC) simulations of the model reveal step pairing in the absence of any additional step attachment barriers. We explore the description of this behavior within an analytic Burton-Cabrera-Frank (BCF)-type step dynamics treatment. Without attachment barriers, conventional kinetic coefficients for the rough and smooth steps are identical, as are the predicted step velocities for a vicinal surface with equal terrace widths. However, we determine refined kinetic coefficients from a two-dimensional discrete deposition-diffusion equation formalism which accounts for step structure. These coefficients are generally higher for rough steps than for smooth steps, reflecting a higher propensity for capture of diffusing terrace adatoms due to a higher kink density. Such refined coefficients also depend on the local environment of the step and can even become negative (corresponding to net detachment despite an excess adatom density) for a smooth step in close proximity to a rough step. Incorporation of these refined kinetic coefficients into a BCF-type step dynamics treatment recovers quantitatively the mesoscale step-pairing behavior observed in the KMC simulations.

  2. Source category survey: secondary copper smelting and refining industry. Final report Oct 79-Jan 80

    SciTech Connect (OSTI)

    Snyder, M.K.; Shobe, F.D.

    1980-05-01

    This report presents the results of a survey of the secondary copper smelting and refining industry to determine the probable impact of the development of new source performance standards under Section 111 of the Clean Air Act. The surveyed industry processes copper scrap to produce pure copper or copper alloy, other than brass and bronze. Secondary copper foundries, which melt and cast high-quality copper scrap without refining it, are excluded. Primary copper smelters and refiners, which produce copper from ore, are also excluded, although they also process copper scrap. Process, emissions, and economic data were gathered by literature searches, contacts with representatives of the industry, trade associations, federal government agencies, and state and local air pollution control agencies, and visits to two plants. The industry's production processes, actual and allowable air emissions, and emission control systems are described. State and local emission regulations are compared. Production and capacity are projected to 1989 and the impact of new source performance standards is assessed.

  3. Adaptive Liquid Crystal Windows

    SciTech Connect (OSTI)

    Taheri, Bahman; Bodnar, Volodymyr

    2011-12-31

    Energy consumption by private and commercial sectors in the U.S. has steadily grown over the last decade. The uncertainty in future availability of imported oil, on which the energy consumption relies strongly, resulted in a dramatic increase in the cost of energy. About 20% of this consumption are used to heat and cool houses and commercial buildings. To reduce dependence on the foreign oil and cut down emission of greenhouse gases, it is necessary to eliminate losses and reduce total energy consumption by buildings. To achieve this goal it is necessary to redefine the role of the conventional windows. At a minimum, windows should stop being a source for energy loss. Ideally, windows should become a source of energy, providing net gain to reduce energy used to heat and cool homes. It is possible to have a net energy gain from a window if its light transmission can be dynamically altered, ideally electronically without the need of operator assistance, providing optimal control of the solar gain that varies with season and climate in the U.S. In addition, the window must not require power from the building for operation. Resolution of this problem is a societal challenge and of national interest and will have a broad global impact. For this purpose, the year-round, allclimate window solution to provide an electronically variable solar heat gain coefficient (SHGC) with a wide dynamic range is needed. AlphaMicron, Inc. (AMI) developed and manufactured 1ft 1ft prototype panels for the worlds first auto-adjusting Adaptive Liquid Crystal Windows (ALCWs) that can operate from sunlight without the need for external power source and demonstrate an electronically adjustable SHGC. This novel windows are based on AlphaMicrons patented e-Tint technology, a guesthost liquid crystal system implemented on flexible, optically clear plastic films. This technology is suitable both for OEM and aftermarket (retro-fitting) lamination to new and existing windows. Low level of power

  4. Re-refinement from deposited X-ray data can deliver improved models for most PDB entries

    SciTech Connect (OSTI)

    Joosten, Robbie P.; Womack, Thomas; Vriend, Gert; Bricogne, Gérard

    2009-02-01

    An evaluation of validation and real-space intervention possibilities for improving existing automated (re-)refinement methods. The deposition of X-ray data along with the customary structural models defining PDB entries makes it possible to apply large-scale re-refinement protocols to these entries, thus giving users the benefit of improvements in X-ray methods that have occurred since the structure was deposited. Automated gradient refinement is an effective method to achieve this goal, but real-space intervention is most often required in order to adequately address problems detected by structure-validation software. In order to improve the existing protocol, automated re-refinement was combined with structure validation and difference-density peak analysis to produce a catalogue of problems in PDB entries that are amenable to automatic correction. It is shown that re-refinement can be effective in producing improvements, which are often associated with the systematic use of the TLS parameterization of B factors, even for relatively new and high-resolution PDB entries, while the accompanying manual or semi-manual map analysis and fitting steps show good prospects for eventual automation. It is proposed that the potential for simultaneous improvements in methods and in re-refinement results be further encouraged by broadening the scope of depositions to include refinement metadata and ultimately primary rather than reduced X-ray data.

  5. Adaptive Materials Inc | Open Energy Information

    Open Energy Information (Open El) [EERE & EIA]

    Michigan Zip: MI 48108 Product: Adaptive Materials Inc (AMI) is a developer of portable fuel cell technology. References: Adaptive Materials Inc1 This article is a stub. You...

  6. Mainstreaming Climate Change Adaptation into Development Planning...

    Open Energy Information (Open El) [EERE & EIA]

    Climate Change Adaptation into Development Planning: A Guide for Practitioners Jump to: navigation, search Tool Summary LAUNCH TOOL Name: Mainstreaming Climate Change Adaptation...

  7. WeADAPT | Open Energy Information

    Open Energy Information (Open El) [EERE & EIA]

    weADAPT Sector Energy, Land, Water, Climate Resource Type Training materials, Lessons learnedbest practices Website http:www.weadapt.org References weADAPT1...

  8. Climate Adaptation for Transportation | Open Energy Information

    Open Energy Information (Open El) [EERE & EIA]

    Climate Adaptation for Transportation Jump to: navigation, search Tool Summary LAUNCH TOOL Name: 03 Climate Adaptation for Transportation AgencyCompany Organization: AASHTO...

  9. Three-step H-P adaptve strategy for the incompressible Navier-Stokes equations

    SciTech Connect (OSTI)

    Oden, J.T.; Wu, W.; Ainsworth, M.

    1995-12-31

    Recently, a reliable a posteriori error estimate was developed, mainly based on the element residual method, for a class of steady state incompressible Navier-Stokes equations. In this paper, using this error estimate, a three-step h-p adaptive strategy is developed to solve incompressible flow problems. The goal of developing an h-p adaptive strategy is to obtain accurate approximate solutions while minimizing computational costs. The basic idea of the three-step h-p adaptive strategy is to solve for the system on the three consecutive meshes, i.e. an initial mesh, an intermediate h-p adaptive mesh, and a final h-p adaptive mesh. Each new adaptive mesh is obtained by estimating the error on the previous mesh and executing a single h- or p- refinement procedure on the previous mesh according to the results of the adaptive strategy. Numerical results indicate that the proposed three-step adaptive strategy produces accurate solutions while keeping the total computational costs under control.

  10. THREE-DIMENSIONAL MOVING-MESH SIMULATIONS OF GALACTIC CENTER CLOUD G2

    SciTech Connect (OSTI)

    Anninos, Peter; Murray, Stephen D.; Fragile, P. Chris; Wilson, Julia

    2012-11-10

    Using three-dimensional, moving-mesh simulations, we investigate the future evolution of the recently discovered gas cloud G2 traveling through the galactic center. We consider the case of a spherical cloud initially in pressure equilibrium with the background. Our suite of simulations explores the following parameters: the equation of state, radial profiles of the background gas, and start times for the evolution. Our primary focus is on how the fate of this cloud will affect the future activity of Sgr A*. From our simulations we expect an average feeding rate in the range of (5-19) Multiplication-Sign 10{sup -8} M {sub Sun} yr{sup -1} beginning in 2013 and lasting for at least 7 years (our simulations stop in year 2020). The accretion varies by less than a factor of three on timescales {<=}1 month, and shows no more than a factor of 10 difference between the maximum and minimum observed rates within any given model. These rates are comparable to the current estimated accretion rate in the immediate vicinity of Sgr A*, although they represent only a small ({approx}< 5%) increase over the current expected feeding rate at the effective inner boundary of our simulations (r = 750, R{sub S} Almost-Equal-To 10{sup 15} cm), where R{sub S} is the Schwarzschild radius of the black hole. Therefore, the breakup of cloud G2 may have only a minimal effect on the brightness and variability of Sgr A* over the next decade. This is because current models of the galactic center predict that most of the gas will be caught up in outflows. However, if the accreted G2 material can remain cold, it may not mix well with the hot, diffuse background gas, and instead accrete efficiently onto Sgr A*. Further observations of G2 will give us an unprecedented opportunity to test this idea. The breakup of the cloud itself may also be observable. By tracking the amount of cloud energy that is dissipated during our simulations, we are able to get a rough estimate of the luminosity associated with

  11. Extending the Shared Socioeconomic Pathways for sub-national impacts, adaptation, and vulnerability studies

    SciTech Connect (OSTI)

    Absar, Syeda Mariya; Preston, Benjamin L.

    2015-05-25

    The exploration of alternative socioeconomic futures is an important aspect of understanding the potential consequences of climate change. While socioeconomic scenarios are common and, at times essential, tools for the impact, adaptation and vulnerability and integrated assessment modeling research communities, their approaches to scenario development have historically been quite distinct. However, increasing convergence of impact, adaptation and vulnerability and integrated assessment modeling research in terms of scales of analysis suggests there may be value in the development of a common framework for socioeconomic scenarios. The Shared Socioeconomic Pathways represents an opportunity for the development of such a common framework. However, the scales at which these global storylines have been developed are largely incommensurate with the sub-national scales at which impact, adaptation and vulnerability, and increasingly integrated assessment modeling, studies are conducted. Our objective for this study was to develop sub-national and sectoral extensions of the global SSP storylines in order to identify future socioeconomic challenges for adaptation for the U.S. Southeast. A set of nested qualitative socioeconomic storyline elements, integrated storylines, and accompanying quantitative indicators were developed through an application of the Factor-Actor-Sector framework. Finally, in addition to revealing challenges and opportunities associated with the use of the SSPs as a basis for more refined scenario development, this study generated sub-national storyline elements and storylines that can subsequently be used to explore the implications of alternative subnational socioeconomic futures for the assessment of climate change impacts and adaptation.

  12. L3:VUQ.VVDA.P2-2.05 William Rider SNL

    U.S. Department of Energy (DOE) all webpages (Extended Search)

    ... showing the topology o f mesh cells used in the Cubit derived mesh across the 3x3 channel. ... error is systematic mesh refinement (or de---refinement, i.e., ...

  13. Steam system opportunity assessment for the pulp and paper, chemical manufacturing, and petroleum refining industries: Main report

    SciTech Connect (OSTI)

    None, None

    2002-10-01

    This report assesses steam generation and use in the pulp and paper, chemical, and petroleum refining industries, and estimates the potential for energy savings from implementation of steam system performance and efficiency improvements.

  14. Training Adaptive Decision-Making.

    SciTech Connect (OSTI)

    Abbott, Robert G.; Forsythe, James C.

    2014-10-01

    Adaptive Thinking has been defined here as the capacity to recognize when a course of action that may have previously been effective is no longer effective and there is need to adjust strategy. Research was undertaken with human test subjects to identify the factors that contribute to adaptive thinking. It was discovered that those most effective in settings that call for adaptive thinking tend to possess a superior capacity to quickly and effectively generate possible courses of action, as measured using the Category Generation test. Software developed for this research has been applied to develop capabilities enabling analysts to identify crucial factors that are predictive of outcomes in fore-on-force simulation exercises.

  15. Evaluation of tropical channel refinement using MPAS-A aquaplanet simulations

    SciTech Connect (OSTI)

    Martini, Matus N.; Gustafson, Jr., William I.; O'Brien, Travis A.; Ma, Po -Lun

    2015-09-13

    Climate models with variable-resolution grids offer a computationally less expensive way to provide more detailed information at regional scales and increased accuracy for processes that cannot be resolved by a coarser grid. This study uses the Model for Prediction Across Scales–Atmosphere (MPAS22A), consisting of a nonhydrostatic dynamical core and a subset of Advanced Research Weather Research and Forecasting (ARW-WRF) model atmospheric physics that have been modified to include the Community Atmosphere Model version 5 (CAM5) cloud fraction parameterization, to investigate the potential benefits of using increased resolution in an tropical channel. The simulations are performed with an idealized aquaplanet configuration using two quasi-uniform grids, with 30 km and 240 km grid spacing, and two variable-resolution grids spanning the same grid spacing range; one with a narrow (20°S–20°N) and one with a wide (30°S–30°N) tropical channel refinement. Results show that increasing resolution in the tropics impacts both the tropical and extratropical circulation. Compared to the quasi-uniform coarse grid, the narrow-channel simulation exhibits stronger updrafts in the Ferrel cell as well as in the middle of the upward branch of the Hadley cell. The wider tropical channel has a closer correspondence to the 30 km quasi-uniform simulation. However, the total atmospheric poleward energy transports are similar in all simulations. The largest differences are in the low-level cloudiness. The refined channel simulations show improved tropical and extratropical precipitation relative to the global 240 km simulation when compared to the global 30 km simulation. All simulations have a single ITCZ. Furthermore, the relatively small differences in mean global and tropical precipitation rates among the simulations are a promising result, and the evidence points to the tropical channel being an effective method for avoiding the extraneous numerical artifacts seen in earlier

  16. Direct Reduction of Waste through Refining of DOE Metal Assets - 13632

    SciTech Connect (OSTI)

    Hargett, Michael C.; Terekhov, Dimitri; Khozan, Kamran M.

    2013-07-01

    CVMR{sup R} presents a technology for refining nickel from the enrichment barrier materials of the DOE that is proven through 100 years of use by the metals industry. CVMR{sup R} applies modern controls, instrumentation for process and monitoring of the system, and innovative production methods to produce a wide spectrum of products that generate new technology applications and improvements to our society and economy. CVMR{sup R} will receive barrier materials as a secure operation and size reduce the metal to a shred that is fed to a carbonylation reactor where nickel is reacted with carbon monoxide and generate nickel carbonyl. The carbonyl will be filtered and decomposed with heat to form a variety of products that include high value nano powders, coated substrates, net shapes and pure nickel. The residue from the reactor will retain radionuclides from enrichment activities. The carbon monoxide will only react and extract nickel under the operating conditions to leave volumetric contamination in the unreacted residue. A demonstration plant was designed and built by CVMR{sup R} and operated by BWXT, to demonstrate the systems capabilities to DOE in 2006. A pilot plant operation precedes the detailed design of the nickel refinery and provides essential data for design, safe work practices, waste characterizations and system kinetics and confirms the project feasibility. CVMR{sup R} produces nickel products that are cleaner than the nickel in U.S. commerce and used by industry today. The CVMR{sup R} process and systems for nickel refining is well suited for DOE materials and will provide value through environmental stewardship, recovery of high value assets, and support of the DOE environmental remediation programs as the refined nickel generates additional long term benefits to local communities. (authors)

  17. Evaluation of Tropical Channel Refinement using MPAS-A Aquaplanet Simulations

    SciTech Connect (OSTI)

    Martini, Matus; Gustafson, William I.; O'Brien, Travis A.; Ma, Po-Lun

    2015-09-13

    Climate models with variable-resolution grids offer a computationally less expensive way to provide more detailed information at regional scales and increased accuracy for processes that cannot be resolved by a coarser grid. This study uses the Model for Prediction Across Scales–Atmosphere (MPAS22A), consisting of a nonhydrostatic dynamical core and a subset of Advanced Research Weather Research and Forecasting (ARW-WRF) model atmospheric physics that have been modified to include the Community Atmosphere Model version 5 (CAM5) cloud fraction parameterization, to investigate the potential benefits of using increased resolution in an tropical channel. The simulations are performed with an idealized aquaplanet configuration using two quasi-uniform grids, with 30 km and 240 km grid spacing, and two variable-resolution grids spanning the same grid spacing range; one with a narrow (20°S–20°N) and one with a wide (30°S–30°N) tropical channel refinement. Results show that increasing resolution in the tropics impacts both the tropical and extratropical circulation. Compared to the quasi-uniform coarse grid, the narrow-channel simulation exhibits stronger updrafts in the Ferrel cell as well as in the middle of the upward branch of the Hadley cell. The wider tropical channel has a closer correspondence to the 30 km quasi-uniform simulation. However, the total atmospheric poleward energy transports are similar in all simulations. The largest differences are in the low-level cloudiness. The refined channel simulations show improved tropical and extratropical precipitation relative to the global 240 km simulation when compared to the global 30 km simulation. All simulations have a single ITCZ. The relatively small differences in mean global and tropical precipitation rates among the simulations are a promising result, and the evidence points to the tropical channel being an effective method for avoiding the extraneous numerical artifacts seen in earlier studies that

  18. Manufacturing Energy and Carbon Footprint - Sector: Petroleum Refining (NAICS 324110), October 2012 (MECS 2006)

    Energy.gov (indexed) [DOE]

    Petroleum Refining (NAICS 324110) Process Energy Electricity and Steam Generation Losses Process Losses 245 Nonprocess Losses 3,546 641 Steam Distribution Losses 145 20 Nonprocess Energy 2,994 Electricity Generation Steam Generation 3,546 110 Prepared for the Advanced Manufacturing Office (AMO) by Energetics Incorporated 62 2,779 127 Generation and Transmission Losses Generation and Transmission Losses 41 275 Onsite Generation 2,840 2,304 927 3,231 402 151 682 9.6 24.3 33.8 64.7 64.3 144.5 176.0

  19. Methods of refining and producing dibasic esters and acids from natural oil feedstocks

    DOE Patents [OSTI]

    Snead, Thomas E.; Cohen, Steven A.; Gildon, Demond L.

    2016-03-15

    Methods are provided for refining natural oil feedstocks and producing dibasic esters and/or dibasic acids. The methods comprise reacting a terminal olefin with an internal olefin in the presence of a metathesis catalyst to form a dibasic ester and/or dibasic acid. In certain embodiments, the olefin esters are formed by reacting the feedstock in the presence of a metathesis catalyst under conditions sufficient to form a metathesized product comprising olefins and esters, separating the olefins from the esters in the metathesized product, and transesterifying the esters in the presence of an alcohol to form a transesterified product having olefin esters.

  20. MX-2500 thermal processor for the treatment of petroleum refining wastes and contaminated soils

    SciTech Connect (OSTI)

    Swanberg, C. )

    1993-05-01

    Separation and Recovery Systems, Inc. (SRS) of Irvine, California is the market leader in supplying hazardous waste and secondary material dewatering and drying services to the petroleum refining industry. In late 1991, SRS introduced the new generation of dryer technology, the MX-2500. The MX-2500 is an electrically heated dryer system that recovers virtually all of the hydrocarbon value of refinery wastes and secondary materials, while producing a solid residue meeting EPA Land Disposal Restriction (LDR) treatment levels which allows the refinery to land dispose of the solids, thereby realizing two objectives: waste minimization and oil recovery/recycling. 2 figs., 3 tabs.