Scalable Low-head Axial-type Venturi-flow Energy Scavenger |...
Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site
Scalable Low-head Axial-type Venturi-flow Energy Scavenger Scalable Low-head Axial-type Venturi-flow Energy Scavenger Scalable Low-head Axial-type Venturi-flow Energy Scavenger...
Piezoelectric axial flow microvalve
Gemmen, Randall; Thornton, Jimmy; Vipperman, Jeffrey S.; Clark, William W.
2007-01-09
This invention is directed to a fuel cell operable with a quantity of fuel and a quantity of an oxidizer to produce electrical power, the fuel cell including a fuel cell body including a labyrinth system structured to permit the fuel and the oxidizer to flow therethrough; at least a first catalyst in fluid communication with the labyrinth; and at least a first microvalve operably disposed within at least a portion of the labyrinth. The microvalve utilizes a deflectable member operable upon the application of a voltage from a voltage source. The microvalve includes an elongated flow channel formed therein and extending substantially longitudinally between the first and second ends to permit substantially longitudinal flow of the fluid therethrough and between the first and second ends; and the deflectable member disposed on the valve body, the deflectable member including at least a first piezoelectric portion that is piezoelectrically operable to deflect the deflectable member between an open position and a closed position upon the application of a voltage, the deflectable member in the closed position being operable to resist the flow of the fluid through the flow channel.
Psoriasis and psoriatic arthritis, axial type
White, Katherine L.
2001-01-01
Psoriasis and psoriatic arthritis, axial type Katherine L.has a 20-year history of psoriasis, progressive psoriaticof psoriatic arthritis and psoriasis: a randomized trial.
Flow Split Venturi, Axially-Rotated Valve
Walrath, David E. (Laramie, WY); Lindberg, William R. (Laramie, WY); Burgess, Robert K. (Sheridan, WY); LaBelle, James (Murrieta, CA)
2000-02-22
The present invention provides an axially-rotated valve which permits increased flow rates and lower pressure drop (characterized by a lower loss coefficient) by using an axial eccentric split venturi with two portions where at least one portion is rotatable with respect to the other portion. The axially-rotated valve typically may be designed to avoid flow separation and/or cavitation at full flow under a variety of conditions. Similarly, the valve is designed, in some embodiments, to produce streamlined flow within the valve. An axially aligned outlet may also increase the flow efficiency. A typical cross section of the eccentric split venturi may be non-axisymmetric such as a semicircular cross section which may assist in both throttling capabilities and in maximum flow capacity using the design of the present invention. Such a design can include applications for freeze resistant axially-rotated valves and may be fully-opened and fully-closed in one-half of a complete rotation. An internal wide radius elbow typically connected to a rotatable portion of the eccentric venturi may assist in directing flow with lower friction losses. A valve actuator may actuate in an axial manner yet be uniquely located outside of the axial flow path to further reduce friction losses. A seal may be used between the two portions that may include a peripheral and diametrical seal in the same plane. A seal separator may increase the useful life of the seal between the fixed and rotatable portions.
Modeling shrouded stator cavity flows in axial-flow compressors
Wellborn, S.R.; Tolchinsky, I.; Okiishi, T.H.
2000-01-01
Experiments and computational analyses were completed to understand the nature of shrouded stator cavity flows. From this understanding, a one-dimensional model of the flow through shrouded stator cavities was developed. This model estimates the leakage mass flow, temperature rise, and angular momentum increase through the cavity, given geometry parameters and the flow conditions at the interface between the cavity and primary flow path. This cavity model consists of two components, one that estimates the flow characteristics through the labyrinth seals and the other that predicts the transfer of momentum due to windage. A description of the one-dimensional model is given. The incorporation and use of the one-dimensional model in a multistage compressor primary flow analysis tool is described. The combination of this model and the primary flow solver was used to reliably simulate the significant impact on performance of the increase of hub seal leakage in a twelve-stage axial-flow compressor. Observed higher temperatures of the hub region fluid, different stage matching, and lower overall efficiencies and core flow than expected could be correctly linked to increased hub seal clearance with this new technique. The importance of including these leakage flows in compressor simulations is shown.
Active control of tip clearance flow in axial compressors
Bae, Jinwoo W
2001-01-01
Control of compressor tip clearance flows is explored in a linear cascade using three types of fluidic actuators; Normal Synthetic Jet (NSJ; unsteady jet normal to the mean flow with zero net mass flux), Directed Synthetic ...
Effect of circumferential groove casing treatment parameters on axial compressor flow range
Hanley, Brian K. (Brian Kyle)
2010-01-01
The impact on compressor flow range of circumferential casing grooves of varying groove depth, groove axial location, and groove axial extent is assessed against that of a smooth casing wall using computational experiments. ...
Effects of Large Energetic Vortices on Axial-Flow Hydrokinetic Turbines B. Gunawan1
Siefert, Chris
Effects of Large Energetic Vortices on Axial-Flow Hydrokinetic Turbines B. Gunawan1 , V.S. Neary1 C production in a model MHK turbine. Results show that the power generated by the turbine is significantly at the centerline of the energy extraction plane, or axial-flow turbine hub elevation, provide high resolution
Effects of axial turbine tip shroud cavity flow on performance and durability
Palmer, Timothy R. (Timothy Richard)
2015-01-01
Flow through tip shroud cavity in a representative axial turbine vane-rotor stage environment is assessed for its role in loss generation and turbine durability. Steady and unsteady three-dimensional flow computations, ...
Secondary air interaction with main flow in axial turbines
Zlatinov, Metodi B. (Metodi Blagoev)
2011-01-01
Secondary air, known as purge air, is injected through seals in the hub and shroud of axial turbines to prevent hot gas ingestion into the endwall cavities. An investigation into the interaction of purge ow with turbine ...
Effect of flow oscillations on axial energy transport in a porous material
Siegel, R. (NASA Lewis Research Center, Cleveland, OH (USA))
1987-02-01
It has been shown analytically and experimentally that flow oscillations of a fluid within a channel can enhance the axial transfer of energy. The transport arises from an axial gradient in fluid temperature resulting from having reservoirs at different temperatures at either end of the channel. The present analysis develops relations for axial energy diffusion in a porous medium with oscillating flow. In some devices, such as the Sterling engine, there are regenerators with oscillating flow. Axial transport in the regenerator provides an energy loss; hence it is desirable to determine what factors can limit this diffusion. A regenerator in the form of a porous medium is difficult to model since the flow is continually disrupted by the irregularities of the porous structure. The formulation here will employ an internal heat transfer coefficient that couples the fluid and solid temperatures. The final result shows how the diffusion depends on the magnitude of the heat transfer coefficient and the maximum fluid displacement.
Performance characteristics of a low pressure cyclone for axial-flow fan exhausts
Simpson, Shay Lynn
1996-01-01
on axial-flow fan exhausts to significantly reduce particulate emissions. Average emission concentrations, cut-point diameters, PMIO emission concentrations, and fractional efficiencies from this cyclone operating at different cyclone inlet velocities...
Blood flow through axially symmetric sections of compliant vessels: new effective closed models
Canic, Suncica
Blood flow through axially symmetric sections of compliant vessels: new effective closed models S-Stokes) equations for blood flow in compliant vessels. Several "effec- tive" one-dimensional models have been used independent ring model) to model the vessel wall behavior. In this work we obtain an effective system
A viscous instability in axially symmetric laminar shear flows
Shakura, Nikolai
2015-01-01
A viscous instability in shearing laminar axisymmetric hydrodynamic flows around a gravitating center is described. In the linearized hydrodynamic equations written in the Boussinesq approximation with microscopic molecular transport coefficients, the instability arises when the viscous dissipation is taken into account in the energy equation. Using the local WKB approximation, we derive a third-order algebraic dispersion equation with two modes representing the modified Rayleigh modes R+ and R-, and the third X-mode. We show that in thin accretion flows the viscosity destabilizes one of the Rayleigh modes in a wide range of wavenumbers, while the X-mode always remains stable. In Keplerian flows, the instability increment is found to be a few Keplerian rotational periods at wavelengths with $kr\\sim 10-50$. This instability may cause turbulence in astrophysical accretion discs even in the absence of magnetic field.
Dynamic control of rotating stall in axial flow compressors using aeromechanical feedback
Gysling, D.L.; Greitzer, E.M.
1995-07-01
Dynamic control of rotating stall in an axial flow compressor has been implemented using aeromechanical feedback. The control strategy developed used an array of wall jets, upstream of a single-stage compressor, which were regulated by locally reacting reed valves. These reed valves responded to the small-amplitude flow-field pressure perturbations that precede rotating stall. The valve design was such that the combined system, compressor plus reed valve controller, was stable under operating conditions that had been unstable without feedback. A 10 percent decrease in the stalling flow coefficient was obtained using the control strategy, and the extension of stall flow range was achieved with no measurable change in the steady-state performance of the compression system. The experiments demonstrate the first use of aeromechanical feedback to extend the stable operating range of an axial flow compressor, and the first use of local feedback and dynamic compensation techniques to suppress rotating stall. The design of the experiment was based on a two-dimensional stall inception model, which incorporated the effect of the aeromechanical feedback. The physical mechanism for rotating stall in axial flow compressors was examined with focus on the role of dynamic feedback in stabilizing compression system instability. As predicted and experimentally demonstrated, the effectiveness of the aeromechanical control strategy depends on a set of nondimensional control parameters that determine the interaction of the control strategy and the rotating stall dynamics.
Measurement of the three-dimensional tip region flow field in an axial compressor
Stauter, R.C. )
1993-07-01
A two-color, five-beam LDV system has been configured to make simultaneous three-component velocity measurements of the flow field in a two-stage axial compressor model. The system has been used to make time-resolved measurements both between compressor blade rows and within the rotating blade passages in an axial compressor. The data show the nature and behavior of the complex, three-dimensional flow phenomena present in the tip region of a compressor as the convect downstream. In particular, the nature of the tip leakage vortex is apparent, being manifested by high blockage as well as the expected vortical motion. The data indicate that the radial flows associated with the tip leakage vortex begin to decrease while within the rotor passage, and that they temporarily increase aft of the passage.
Impact of unsteady flow processes on the performance of a high speed axial flow compressor
Botros, Barbara Brenda
2008-01-01
This thesis examines the unsteady interactions between blade rows in a high Mach number, highly-loaded compressor stage. Two straight vane/rotor configurations with different axial spacing between vane and rotor are ...
Rotor whirl forces induced by the tip clearance effect in axial flow compressors
Ehrich, F. )
1993-10-01
It is now widely recognized that destabilizing forces, tending to generate forward rotor whirl, are generated in axial flow turbines as a result of the nonuniform torque induced by the nonuniform tip-clearance in a deflected rotor--the so called Thomas/Alford force. It is also recognized that there will be a similar effect in axial flow compressors, but qualitative considerations cannot definitively establish the magnitude or even the direction of the induced whirling forces--that is, if they will tend to forward or backward whirl. Applying a parallel compressor model to simulate the operation of a compressor rotor deflected radially in its clearance, it is possible to derive a quantitative estimate of the proportionality factor [beta] which relates the Thomas/Alford force in axial flow compressors (i.e., the tangential force generated by a radial deflection of the rotor) to the torque level in the compressor. The analysis makes use of experimental data from the GE Aircraft Engines Low Speed Research Compressor facility comparing the performance of three different axial flow compressors, each with four stages (typical of a mid-block of an aircraft gas turbine compressor) at two different clearances. It is found that the value of [beta] is in the range of +0.27 to [minus]0.71 in the vicinity of the stages' nominal operating line and +0.08 to [minus]1.25 in the vicinity of the stages' operation at peak efficiency. The value of [beta] reaches a level of between [minus]1.16 and [minus]3.36 as the compressor is operated near its stalled condition.
Tip clearance flows in axial compressors: stall inception and stability enhancement
Weichert, Stephanie April
2012-02-07
and 91 figures. Part of this dissertation has been presented in the following publication: Weichert, S., Day, I. & Freeman, C. (2011) Self-Regulating Casing Treat- ment for Axial Compressor Stability Enhancement. Proceedings of ASME Turbo Expo 2011, June... -span if unspecified W Rotor Relative Flow Velocity, mid-span if unspecified xii Superscripts and Subscripts 0 Stagnation condition 1 Rotor inlet conditions 2 Rotor exit, stator inlet conditions 3 Stator exit conditions a1 Deverson compressor bellmouth inlet d2...
Arima, T.; Sonoda, T.; Shirotori, M.; Tamura, A.; Kikuchi, K.
1999-01-01
The authors have developed a computer simulation code for three-dimensional viscous flow in turbomachinery based on the time-averaged compressible Navier-Stokes equations and a low-Reynolds-number {kappa}-{epsilon} turbulence model. It is described in detail in this paper. The code is used to compute the flow fields for two types of rotor (a transonic fan NASA Rotor 67 and a transonic axial compressor NASA rotor 37), and numerical results are compared to experimental data based on aerodynamic probe and laser anemometer measurements. In the case of Rotor 67, calculated and experimental results are compared under the design speed to validate the code. The calculated results show good agreement with the experimental data, such as the rotor performance map and the spanwise distribution of total pressure, total temperature, and flow angle downstream of the rotor. In the case of Rotor 37, detailed comparisons between the numerical results and the experimental data are made under the design speed condition to assess the overall quality of the numerical solution. Furthermore, comparisons under the part-speed condition are used to investigate a flow field without passage shock. The results are well predicted qualitatively. However, considerable quantitative discrepancies remain in predicting the flow near the tip. In order to assess the predictive capabilities of the developed code, computed flow structures are presented with the experimental data for each rotor and the cause of the discrepancies is discussed.
Performance Evaluation of Axial Flow AG-1 FC and Prototype FM (High Strength) HEPA Filters - 13123
Giffin, Paxton K.; Parsons, Michael S.; Wilson, John A.; Waggoner, Charles A. [Institute for Clean Energy Technology, Mississippi State University, 205 Research Blvd Starkville, MS 39759 (United States)] [Institute for Clean Energy Technology, Mississippi State University, 205 Research Blvd Starkville, MS 39759 (United States)
2013-07-01
High efficiency particulate air (HEPA) filters are routinely used in DOE nuclear containment activities. The Nuclear Air Cleaning Handbook (NACH) stipulates that air cleaning devices and equipment used in DOE nuclear applications must meet the American Society of Mechanical Engineers (ASME) Code on Nuclear Air and Gas Treatment (AG-1) standard. This testing activity evaluates two different axial flow HEPA filters, those from AG-1 Sections FC and FM. Section FM is under development and has not yet been added to AG-1 due to a lack of qualification data available for these filters. Section FC filters are axial flow units that utilize a fibrous glass filtering medium. The section FM filters utilize a similar fibrous glass medium, but also have scrim backing. The scrim-backed filters have demonstrated the ability to endure pressure impulses capable of completely destroying FC filters. The testing activities presented herein will examine the total lifetime loading for both FC and FM filters under ambient conditions and at elevated conditions of temperature and relative humidity. Results will include loading curves, penetration curves, and testing condition parameters. These testing activities have been developed through collaborations with representatives from the National Nuclear Security Administration (NNSA), DOE Office of Environmental Management (DOE-EM), New Mexico State University, and Mississippi State University. (authors)
Analysis of instability inception in high-speed multistage axial-flow compressors
Hendricks, G.J.; Sabnis, J.S.; Feulner, M.R.
1997-10-01
A nonlinear, two-dimensional, compressible dynamic model has been developed to study rotating stall/surge inception and development in high-speed, multistage, axial flow compressors. The flow dynamics are represented by the unsteady Euler equations, solved in each interblade row gap and inlet and exit ducts as two-dimensional domains, and in each blade passage as a one-dimensional domain. The resulting equations are solved on a computational grid. The boundary conditions between domains are represented by ideal turning coupled with empirical loss and deviation correlations. Results are presented comparing model simulations to instability inception data of an eleven stage, high-pressure-ratio compressor operating at both part and full power, and the results analyzed in the context of a linear modal analysis.
Evaluation of behaviour and survival of fish exposed to an axial-flow hydrokinetic turbine
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
Amaral, Stephen; Bevelhimer, Mark S; Cada, Glenn F; Giza, Daniel; Jacobsen, Paul; McMahon, Brian; Pracheil, Brenda M
2015-01-01
Previous studies have evaluated fish injury and mortality at hydrokinetic (HK) turbines, but because these studies focused on the impacts of these turbines in situ they were unable to evaluate fish responses to controlled environmental characteristics (e.g., current velocity and light or dark conditions). In this study, we used juvenile hybrid Striped Bass (HSB; Striped Bass Morone saxatilis White Bass M. chrysops; N D 620), Rainbow Trout Oncorhynchus mykiss (N D 3,719), and White Sturgeon Acipenser transmontanus (N D 294) in a series of laboratory experiments to (1) evaluate the ability of fish to avoid entrainment through an axial-flow HKmore »turbine, (2) evaluate fish injury and survival associated with turbine entrainment, and (3) compare the effects of different HK turbines on fish. We found that the probability of turbine entrainment was species dependent and highest for HSB. Across species, current velocity influenced entrainment probability. Among entrained fish, observed survival rates were generally >0.95. The probability of injury for surviving entrained fish only differed from that for nonentrained fish for Rainbow Trout and in general was not >0.20. The probability of injury following entrainment was greater only for HSB, although there were no differences in injury rates between fish that were turbine entrained and those that were not, suggesting that injuries were not turbine related. Taking turbine entrainment, survival, and injury estimates together allowed us to estimate the probability of a randomly selected fish in a population proximate to an HK turbine surviving passage or remaining uninjured after passage. For species and current velocities for which there was a significant effect due to entrainment, we estimated, for instance, that HSB had a survival probability of 0.95 and that Rainbow Trout and White Sturgeon had a >0.99 probability of survival. Similarly, by combining these estimates with those from previous studies, we derived total passage survival probabilities >0.90 but generally approaching 1.00 across different HK turbine types, fish species, and fish lengths.« less
Evaluation of behavior and survival of fish exposed to an axial-flow hydrokinetic turbine
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
Amaral, Stephen V.; Bevelhimer, Mark S.; ?ada, Glenn F.; Giza, Daniel J.; Jacobson, Paul T.; McMahon, Brian J.; Pracheil, Brenda M.
2015-02-06
Previous studies have evaluated fish injury and mortality at hydrokinetic (HK) turbines, but because these studies focused on the impacts of these turbines in situ they were unable to evaluate fish responses to controlled environmental characteristics (e.g., current velocity and light or dark conditions). In this study, we used juvenile hybrid Striped Bass (HSB; Striped Bass Morone saxatilis White Bass M. chrysops; N D 620), Rainbow Trout Oncorhynchus mykiss (N D 3,719), and White Sturgeon Acipenser transmontanus (N D 294) in a series of laboratory experiments to (1) evaluate the ability of fish to avoid entrainment through an axial-flow HKmore »turbine, (2) evaluate fish injury and survival associated with turbine entrainment, and (3) compare the effects of different HK turbines on fish. We found that the probability of turbine entrainment was species dependent and highest for HSB. Across species, current velocity influenced entrainment probability. Among entrained fish, observed survival rates were generally >0.95. The probability of injury for surviving entrained fish only differed from that for nonentrained fish for Rainbow Trout and in general was not >0.20. The probability of injury following entrainment was greater only for HSB, although there were no differences in injury rates between fish that were turbine entrained and those that were not, suggesting that injuries were not turbine related. Taking turbine entrainment, survival, and injury estimates together allowed us to estimate the probability of a randomly selected fish in a population proximate to an HK turbine surviving passage or remaining uninjured after passage. For species and current velocities for which there was a significant effect due to entrainment, we estimated, for instance, that HSB had a survival probability of 0.95 and that Rainbow Trout and White Sturgeon had a >0.99 probability of survival. By combining these estimates with those from previous studies, we derived total passage survival probabilities >0.90 but generally approaching 1.00 across different HK turbine types, fish species, and fish lengths.« less
Flow and axial dispersion in a sinusoidal-walled tube: Effects of inertial and unsteady flows
Richmond, Marshall C.; Perkins, William A.; Scheibe, Timothy D.; Lambert, Adam; Wood, Brian D.
2013-12-01
Dispersion in porous media flows has been the subject of much experimental, theoretical and numerical study. Here we consider a wavy-walled tube (a three-dimensional tube with sinusoidally-varying diameter) as a simplified conceptualization of flow in porous media, where constrictions represent pore throats and expansions pore bodies. A theoretical model for effective (macroscopic) longitudinal dispersion in this system has been developed by volume averaging the microscale velocity field. Direct numerical simulation using computational fluid dynamics (CFD) methods was used to compute velocity fields by solving the Navier-Stokes equations, and also to numerically solve the volume averaging closure problem, for a range of Reynolds numbers (Re) spanning the low-Re to inertial flow regimes, including one simulation at Re = 449 for which unsteady flow was observed. Dispersion values were computed using both the volume averaging solution and a random walk particle tracking method, and results of the two methods were shown to be consistent. Our results are compared to experimental measurements of dispersion in porous media and to previous theoretical results for the low-Re, Stokes flow regime. In the steady inertial regime we observe an power-law increase in effective longitudinal dispersion (DL) with Re, consistent with previous results. This rapid rate of increase is caused by trapping of solute in expansions due to flow separation (eddies). For the unsteady case (Re = 449), the rate of increase of DL with Re was smaller than that observed at lower Re. Velocity fluctuations in this regime lead to increased rates of solute mass transfer between the core flow and separated flow regions, thus diminishing the amount of tailing caused by solute trapping in eddies and thereby reducing longitudinal dispersion.
Bifurcation analysis of surge and rotating stall in axial flow compressors
Abed, E.H. ); Houpt, P.K. . Corporate Research and Development Center); Hosny, W.M. . Engine Operability Div.)
1993-10-01
The surge and rotating stall post-instability behaviors of axial flow compressors are investigated from a bifurcation-theoretic perspective, using a model and system data presented by Greitzer (1976a). For this model, a sequence of local and global bifurcations of the nonlinear system dynamics is uncovered. This includes a global bifurcation of a pair of large-amplitude periodic solutions. Resulting from this bifurcation are a stable oscillation (surge) and an unstable oscillation (antisurge). The latter oscillation is found to have a deciding significance regarding the particular post-instability behavior experienced by the compressor. These results are used to reconstruct Greitzer's (1976b) findings regarding the manner in which post-instability behavior depends on system parameters. Although the model does not directly reflect non axisymmetric dynamics, use of a steady-state compressor characteristic approximating the measured characteristic of Greitzer (1976a) is found to result in conclusions that compare well with observation. Thus, the paper gives a convenient and simple explanation of the boundary between surge and rotating stall behaviors, without the use of more intricate models and analyses including non axisymmetric flow dynamics.
Rotating stall control of an axial flow compressor using pulsed air injection
D`Andrea, R.; Behnken, R.L.
1997-10-01
This paper presents the use of pulsed air injection to control rotating stall in a low-speed, axial flow compressor. In the first part of the paper, the injection of air is modeled as an unsteady shift of the compressor characteristic, and incorporated into a low dimensional model of the compressor. By observing the change in the bifurcation behavior of this model subject to nonlinear feedback, the viability of various air injection orientations is established. An orientation consistent with this analysis is then used for feedback control. By measuring the unsteady pressures near the rotor face, a control algorithm determines the magnitude and phase of the first mode of rotating stall and controls the injection of air in the front of the rotor face. Experimental results show that this technique eliminates the hysteresis loop normally associated with rotating stall. A parametric study is used to determine the optimal control parameters for suppression of stall. The resulting control strategy is also shown to suppress surge when a plenum is present. Using a high-fidelity model, the main features of the experimental results are duplicated via simulations.
Singh, Punit; Nestmann, Franz
2010-09-15
A detailed experimental investigation of the effects of exit blade geometry on the part-load performance of low-head, axial flow propeller turbines is presented. Even as these turbines find important applications in small-scale energy generation using micro-hydro, the relationship between the layout of blade profile, geometry and turbine performance continues to be poorly characterized. The experimental results presented here help understand the relationship between exit tip angle, discharge through the turbine, shaft power, and efficiency. The modification was implemented on two different propeller runners and it was found that the power and efficiency gains from decreasing the exit tip angle could be explained by a theoretical model presented here based on classical theory of turbomachines. In particular, the focus is on the behaviour of internal parameters like the runner loss coefficient, relative flow angle at exit, mean axial flow velocity and net tangential flow velocity. The study concluded that the effects of exit tip modification were significant. The introspective discussion on the theoretical model's limitation and test facility suggests wider and continued experimentation pertaining to the internal parameters like inlet vortex profile and exit swirl profile. It also recommends thorough validation of the model and its improvement so that it can be made capable for accurate characterization of blade geometric effects. (author)
Molecular tagging velocimetry measurements of axial flow in a concentrated vortex core
Koochesfahani, Manoochehr M.
, hydrocyclones) and natural (e.g., tornadoes, hurricanes, dust devils) flow fields. The interaction of vortices
Computation of the Field in an Axial Gap, Trapped-Flux Type Superconducting Electric Machine
Shen, Zejun; Ainslie, Mark D.; Campbell, Archie M.; Cardwell, David A.
2014-11-04
Abstract—The Bulk Superconductivity Group at the University of Cambridge is currently investigating the use of high temper- ature superconductors in wire and bulk form to increase the electrical and magnetic loading of an axial gap, trapped flux... electric machines are an importantapplication of superconducting materials in both bulk and wire forms. Bulk high temperature superconductors, in partic- ular, are capable of trapping magnetic fields greater than 17 T below 30 K [1], [2], as well as up to 3...
Kumar Awasthi, Mukesh, E-mail: mukeshiitr.kumar@gmail.com [Department of Mathematics, University of Petroleum and Energy Studies, Dehradun (India)
2014-04-15
We study the linear analysis of electrohydrodynamic capillary instability of the interface between two viscous, incompressible and electrically conducting fluids in a fully saturated porous medium, when the phases are enclosed between two horizontal cylindrical surfaces coaxial with the interface and, when there is mass and heat transfer across the interface. The fluids are subjected to a constant electric field in the axial direction. Here, we use an irrotational theory in which the motion and pressure are irrotational and the viscosity enters through the jump in the viscous normal stress in the normal stress balance at the interface. A quadratic dispersion relation that accounts for the growth of axisymmetric waves is obtained and stability criterion is given in terms of a critical value of wave number as well as electric field. It is observed that heat transfer has stabilizing effect on the stability of the considered system while medium porosity destabilizes the interface. The axial electric field has dual effect on the stability analysis.
Combustion in a Transonic Flow with Large Axial and Transverse Pressure Gradients
Liu, Feng
that we have named "turbine burners." References 17 present the progress to date on this emerging for bypass flows (turbofans), afterburners, and turbine burners. A simplified thermodynamic cy- cle portrayed for the turbine burner is given in Figure 2. Turbine burners are shown with continuous com- bustion through
Interactions between turbulent open channel flow, power and the wake of an axial-flow marine turbine
Siefert, Chris
turbine Leonardo P. Chamorro1 , Craig Hill1 , Vincent Neary2 , Budi Gunawan2 , Roger Arndt1 , Fotis-flow marine hydrokinetic turbines was lacking. Advancing this area of knowledge within the field of marine and hydrokinetic energy research, development, and deployment will lead to more efficient turbine operations
Christov, Ivan C.; Lueptow, Richard M.; Ottino, Julio M.; Sturman, Rob
2014-05-22
We study three-dimensional (3D) chaotic dynamics through an analysis of transport in a granular flow in a half-full spherical tumbler rotated sequentially about two orthogonal axes (a bi-axial “blinking” tumbler). The flow is essentially quasi-two-dimensional in any vertical slice of the sphere during rotation about a single axis, and we provide an explicit exact solution to the model in this case. Hence, the cross-sectional flow can be represented by a twist map, allowing us to express the 3D flow as a linked twist map (LTM). We prove that if the rates of rotation about each axis are equal, then (in the absence of stochasticity) particle trajectories are restricted to two-dimensional (2D) surfaces consisting of a portion of a hemispherical shell closed by a “cap''; if the rotation rates are unequal, then particles can leave the surface they start on and traverse a volume of the tumbler. The period-one structures of the governing LTM are examined in detail: analytical expressions are provided for the location of period-one curves, their extent into the bulk of the granular material, and their dependence on the protocol parameters (rates and durations of rotations). Exploiting the restriction of trajectories to 2D surfaces in the case of equal rotation rates about the axes, a method is proposed for identifying and constructing 3D Kolmogorov--Arnold--Moser (KAM) tubes around the normally elliptic period-one curves. The invariant manifold structure arising from the normally hyperbolic period-one curves is also examined. When the motion is restricted to 2D surfaces, the structure of manifolds of the hyperbolic points in the bulk differs from that corresponding to hyperbolic points in the flowing layer. Each is reminiscent of a template provided by a non-integrable perturbation to a Hamiltonian system, though the governing LTM is not. This highlights the novel 3D chaotic behaviors observed in this model dynamical system.
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
Christov, Ivan C.; Lueptow, Richard M.; Ottino, Julio M.; Sturman, Rob
2014-05-22
We study three-dimensional (3D) chaotic dynamics through an analysis of transport in a granular flow in a half-full spherical tumbler rotated sequentially about two orthogonal axes (a bi-axial “blinking” tumbler). The flow is essentially quasi-two-dimensional in any vertical slice of the sphere during rotation about a single axis, and we provide an explicit exact solution to the model in this case. Hence, the cross-sectional flow can be represented by a twist map, allowing us to express the 3D flow as a linked twist map (LTM). We prove that if the rates of rotation about each axis are equal, then (inmore »the absence of stochasticity) particle trajectories are restricted to two-dimensional (2D) surfaces consisting of a portion of a hemispherical shell closed by a “cap''; if the rotation rates are unequal, then particles can leave the surface they start on and traverse a volume of the tumbler. The period-one structures of the governing LTM are examined in detail: analytical expressions are provided for the location of period-one curves, their extent into the bulk of the granular material, and their dependence on the protocol parameters (rates and durations of rotations). Exploiting the restriction of trajectories to 2D surfaces in the case of equal rotation rates about the axes, a method is proposed for identifying and constructing 3D Kolmogorov--Arnold--Moser (KAM) tubes around the normally elliptic period-one curves. The invariant manifold structure arising from the normally hyperbolic period-one curves is also examined. When the motion is restricted to 2D surfaces, the structure of manifolds of the hyperbolic points in the bulk differs from that corresponding to hyperbolic points in the flowing layer. Each is reminiscent of a template provided by a non-integrable perturbation to a Hamiltonian system, though the governing LTM is not. This highlights the novel 3D chaotic behaviors observed in this model dynamical system.« less
Suction recirculation and its effects upon axial-flow pump power consumption
Prince, Tony M.
1983-01-01
1 Test Procedure Outline 2 Section and Pump Critical Flowrates and Speeds. 63 91 3 Power Coefficient and Reynolds Number Based on Cone Radius. 100 4 Power Coefficient and Reynolds Number Based on Surface Area. 101 5 Power Coefficient... Variation with NPSH with Q rl 54 Head Variation with NPSH with Q 2 . r2 55 Head Variation with NPSH with Q 3. r3' 120 128 129 130 131 134 135 136 CHAPTER I INTRODUCTION Pumps of different types are used to displace liquids from one location...
Stage effects on stalling and recovery of a high-speed 10-stage axial-flow compressor
Copenhaver, W.W.
1988-01-01
Results of a high-speed 10-stage axial-flow compressor test involving overall compressor and individual stage performance while stalling and operating in quasi-steady rotating stall are described. Test procedures and data-acquisition methods used to obtain the dynamic stalling and quasi-steady in-stall data are explained. Unstalled and in-stall time-averaged data obtained from the compressor operating at five different shaft speeds and one off-schedule variable vane condition are presented. Effects of compressor speed and variable geometry on overall compressor in-stall pressure rise and hysteresis extent are illustrated through the use of quasi-steady-stage temperature rise and pressure-rise characteristics. Results indicate that individual stage performance during overall compressor rotating stall operation varies considerably throughout the length of the compressor. The measured high-speed 10-stage test compressor individual stage pressure and temperature characteristics were input into a stage-by-stage dynamic compressor performance model. Comparison of the model results and measured pressures provided the additional validation necessary to demonstrate the model's ability to predict high-speed multistage compressor stalling and in-stall performance.
Flow Flow Flow Flow Flow Flow Flow Flow Flow Flow
Marchese, Francis
Flow Flow Flow Flow Flow Flow Flow Flow Flow Flow Flow Flow Flow Flow Flow Flow Flow Flow Flow Flow Flow Flow Flow Flow Flow Flow Flow Flow Flow Flow Flow Flow Flow Flow Flow Flow Flow Flow Flow Flow Flow Flow Flow Flow Flow Flow Flow Flow Flow Flow Flow Flow Flow Flow Flow Flow Flow Flow Flow Flow
Boyer, Edmond
pressure signals upstream and downstream the pump and the exchanger. The pressure fluctuations. Keywords: Axial Pump, Pressure Fluctuations, Cavitation, Tubular Exchanger, Test Bench NOMENCLATURE Roman AND A TUBULAR EXCHANGER Mois´es Solis, Florent Ravelet,a) Sofiane Khelladi, and Farid Bakir Arts et Metiers
Koochesfahani, Manoochehr M.
of confined flows such as vortex chambers, and swirl separators (e.g., hydrocyclones). More recently
Inertial waves and mean velocity profiles in a rotating pipe and a circular annulus with axial flow
Yang, Yantao; Wu, J Z; Orlandi, Paolo
2015-01-01
In this paper we solve the inviscid inertial wave solutions in a circular pipe or annulus rotating constantly about its axis with moderate angular speed. The solutions are constructed by the so-called helical wave functions. We reveal that the mean velocity profiles must satisfy certain conditions to accommodate the inertial waves at the bulk region away from boundary. These conditions require the axial and azimuthal components of the mean velocity take the shapes of the zeroth and first order Bessel functions of the first kind, respectively. The theory is then verified by data obtained from direct numerical simulations for both rotating pipe and circular annulus, and excellent agreement is found between theory and numerical results. Large scale vortex clusters are found in the bulk region where the mean velocity profiles match the theoretical predictions. The success of the theory in rotating pipe, circular annulus, and streamwise rotating channel suggests that such inertial waves are quite common in wall bo...
Split Venturi, Axially-Rotated Valve
Walrath, David E. (Laramie, WY); Lindberg, William R. (Laramie, WY); Burgess, Robert K. (Sheridan, WY)
2000-08-29
The present invention provides an axially-rotated valve which permits increased flow rates and lower pressure drop (characterized by a lower loss coefficient) by using an axial eccentric split venturi with two portions where at least one portion is rotatable with respect to the other portion. The axially-rotated valve typically may be designed to avoid flow separation and/or cavitation at full flow under a variety of conditions. Similarly, the valve is designed, in some embodiments, to produce streamlined flow within the valve. A typical cross section of the eccentric split venturi may be non-axisymmetric such as a semicircular cross section which may assist in both throttling capabilities and in maximum flow capacity using the design of the present invention. Such a design can include applications for freeze resistant axially-rotated valves and may be fully-opened and fully-closed in one-half of a complete rotation. An internal wide radius elbow typically connected to a rotatable portion of the eccentric venturi may assist in directing flow with lower friction losses. A valve actuator may actuate in an axial manner yet be uniquely located outside of the axial flow path to further reduce friction losses. A seal may be used between the two portions that may include a peripheral and diametrical seal in the same plane.
Crossflow instability in rotor-stator flows with throughflow , M.-P. Chauve
Paris-Sud XI, Université de
Crossflow instability in rotor-stator flows with throughflow S. Poncet , M.-P. Chauve We study. As the axial velocity profiles exhibit inflexion points, this instability is of crossflow type. From
Flow Characteristics Analysis of Widows' Creek Type Control Valve for Steam Turbine Control
Yoo, Yong H.; Sohn, Myoung S.; Suh, Kune Y.
2006-07-01
The steam turbine converts the kinetic energy of steam to mechanical energy of rotor blades in the power conversion system of fossil and nuclear power plants. The electric output from the generator of which the rotor is coupled with that of the steam turbine depends on the rotation velocity of the steam turbine bucket. The rotation velocity is proportional to the mass flow rate of steam entering the steam turbine through valves and nozzles. Thus, it is very important to control the steam mass flow rate for the load following operation of power plants. Among various valves that control the steam turbine, the control valve is most significant. The steam flow rate is determined by the area formed by the stem disk and the seat of the control valve. While the ideal control valve linearly controls the steam mass flow rate with its stem lift, the real control valve has various flow characteristic curves pursuant to the stem lift type. Thus, flow characteristic curves are needed to precisely design the control valves manufactured for the operating conditions of nuclear power plants. OMEGA (Optimized Multidimensional Experiment Geometric Apparatus) was built to experimentally study the flow characteristics of steam flowing inside the control valve. The Widows' Creek type control valve was selected for reference. Air was selected as the working fluid in the OMEGA loop to exclude the condensation effect in this simplified approach. Flow characteristic curves were plotted by calculating the ratio of the measured mass flow rate versus the theoretical mass flow rate of the air. The flow characteristic curves are expected to be utilized to accurately design and operate the control valve for fossil as well as nuclear plants. (authors)
Suchoza, B.P.; Becse, I.
1988-11-08
An apparatus for measuring the hydraulic axial thrust of a pump under operation conditions is disclosed. The axial thrust is determined by forcing the rotating impeller off of an associated thrust bearing by use of an elongate rod extending coaxially with the pump shaft. The elongate rod contacts an impeller retainer bolt where a bearing is provided. Suitable measuring devices measure when the rod moves to force the impeller off of the associated thrust bearing and the axial force exerted on the rod at that time. The elongate rod is preferably provided in a housing with a heat dissipation mechanism whereby the hot fluid does not affect the measuring devices. 1 fig.
Suchoza, Bernard P. (McMurray, PA); Becse, Imre (Washington, PA)
1988-01-01
An apparatus for measuring the hydraulic axial thrust of a pump under operation conditions is disclosed. The axial thrust is determined by forcing the rotating impeller off of an associated thrust bearing by use of an elongate rod extending coaxially with the pump shaft. The elongate rod contacts an impeller retainer bolt where a bearing is provided. Suitable measuring devices measure when the rod moves to force the impeller off of the associated thrust bearing and the axial force exerted on the rod at that time. The elongate rod is preferably provided in a housing with a heat dissipation mechanism whereby the hot fluid does not affect the measuring devices.
Pinch-type instability experiments in magnetic Taylor-Couette flows
Pinch-type instability experiments in magnetic Taylor-Couette flows G. R¨udiger1 and D.A. Shalybkov.F. Ioffe Institute of Physics and Technology, 194021 St. Petersburg, Russia E-mail: gruediger enough Hartmann numbers the toroidal field is always (pinch-)unstable independent of any details
Molecular-Flow Properties of RIB Type Vapor-Transport Systems Using a Fast-Valve
Alton, Gerald D [ORNL] [ORNL; Bilheux, Hassina Z [ORNL] [ORNL; Zhang, Y. [Oak Ridge National Laboratory (ORNL)] [Oak Ridge National Laboratory (ORNL); Liu, Yuan [ORNL] [ORNL
2014-01-01
The advent of the fast-valve device, described previously, permits measurement of molecular-flow times of chemically active or inactive gaseous species through radioactive ion beam (RIB) target ion source systems, independent of size, geometry and materials of construction. Thus, decay losses of short-half-life RIBs can be determined for a given target/vapor-transport system in advance of on-line operation, thereby ascertaining the feasibility of the system design for successful processing of a given isotope. In this article, molecular-flow-time theory and experimentally measured molecular-flow time data are given for serial- and parallel-coupled Ta metal RIB vapor-transport systems similar to those used at ISOL based RIB facilities. In addition, the effect of source type on the molecular-flow time properties of a given system is addressed, and a chemical passivation method for negating surface adsorption enthalpies for chemically active gaseous species on Ta surfaces is demonstrated.
Lin, Zhihong
and electron transport. Furthermore, the effect of ITG generated zonal flows regarded as a wave-type mean flow are generated as a beat wave or a modulational instability. Meanwhile, they act back on the turbulence, China 2) Graduate School of Energy Science, Kyoto University, 611-0011 Gokasho, Uji, Japan 3) Department
Rothermel, Gregg
no research evaluating the tradeoffs associated with the use of type in- ference algorithms to improve control on representations of program control flow. The accuracy of these representations can be important flow effects of exceptions, but to date, there has been no study of whether the use of these algorithms
Axially staggered seed-blanket reactor fuel module construction
Cowell, Gary K. (Monroeville, PA); DiGuiseppe, Carl P. (West Mifflin, PA)
1985-01-01
A heterogeneous nuclear reactor of the seed-blanket type is provided wher the fissile (seed) and fertile (blanket) nuclear fuels are segregated axially within each fuel element such that fissile and fertile regions occur in an alternating pattern along the length of the fuel element. Further, different axial stacking patterns are used for the fuel elements of at least two module types such that when modules of different types are positioned adjacent to one another, the fertile regions of the modules are offset or staggered. Thus, when a module of one type is surrounded by modules of the second type the fertile regions thereof will be surrounded on all sides by fissile material. This provides enhanced neutron communication both radially and axially, thereby resulting in greater power oscillation stability than other axial arrangements. The arrangements of the fissile and fertile regions in an alternating axial manner minimizes the radial power peaking factors and provides a more optional thermal-hydraulic design than is afforded by radial arrangements.
Small core axial compressors for high efficiency jet aircraft
DiOrio, Austin Graf
2012-01-01
This thesis quantifies mechanisms that limit efficiency in small core axial compressors, defined here as compressor exit corrected flow between 1.5 and 3.0 lbm/s. The first part of the thesis describes why a small engine ...
Axially Tapered And Bilayer Microchannels For Evaporative Cooling Devices
Nilson, Robert (Cardiff, CA); Griffiths, Stewart (Livermore, CA)
2005-10-04
The invention consists of an evaporative cooling device comprising one or more microchannels whose cross section is axially reduced to control the maximum capillary pressure differential between liquid and vapor phases. In one embodiment, the evaporation channels have a rectangular cross section that is reduced in width along a flow path. In another embodiment, channels of fixed width are patterned with an array of microfabricated post-like features such that the feature size and spacing are gradually reduced along the flow path. Other embodiments incorporate bilayer channels consisting of an upper cover plate having a pattern of slots or holes of axially decreasing size and a lower fluid flow layer having channel widths substantially greater than the characteristic microscale dimensions of the patterned cover plate. The small dimensions of the cover plate holes afford large capillary pressure differentials while the larger dimensions of the lower region reduce viscous flow resistance.
Feedback control of inertial microfluidics using axial control forces
Christopher Prohm; Holger Stark
2014-02-03
Inertial microfluidics is a promising tool for many lab-on-a-chip applications. Particles in channel flows with Reynolds numbers above one undergo cross-streamline migration to a discrete set of equilibrium positions in square and rectangular channel cross sections. This effect has been used extensively for particle sorting and the analysis of particle properties. Using the lattice Boltzmann method, we determine equilibrium positions in square and rectangular cross sections and classify their types of stability for different Reynolds numbers, particle sizes, and channel aspect ratios. Our findings thereby help to design microfluidic channels for particle sorting. Furthermore, we demonstrate how an axial control force, which slows down the particles, shifts the stable equilibrium position towards the channel center. Ultimately, the particles then stay on the centerline for forces exceeding a threshold value. This effect is sensitive to particle size and channel Reynolds number and therefore suggests an efficient method for particle separation. In combination with a hysteretic feedback scheme, we can even increase particle throughput.
Cyclone reactor with internal separation and axial recirculation
Becker, Frederick E. (Reading, MA); Smolensky, Leo A. (Concord, MA)
1989-01-01
A cyclone combustor apparatus contains a circular partition plate containing a central circular aperture. The partition plate divides the apparatus into a cylindrical precombustor chamber and a combustor chamber. A coal-water slurry is passed axially into the inlet end of the precombustor chamber, and primary air is passed tangentially into said chamber to establish a cyclonic air flow. Combustion products pass through the partition plate aperture and into the combustor chamber. Secondary air may also be passed tangentially into the combustor chamber adjacent the partition plate to maintain the cyclonic flow. Flue gas is passed axially out of the combustor chamber at the outlet end and ash is withdrawn tangentially from the combuston chamber at the outlet end. A first mixture of flue gas and ash may be tangentially withdrawn from the combustor chamber at the outlet end and recirculated to the axial inlet of the precombustor chamber with the coal-water slurry. A second mixture of flue gas and ash may be tangentially withdrawn from the outlet end of the combustor chamber and passed to a heat exchanger for cooling. Cooled second mixture is then recirculated to the axial inlet of the precombustor chamber. In another embodiment a single cyclone combustor chamber is provided with both the recirculation streams of the first mixture and the second mixture.
Cyclone reactor with internal separation and axial recirculation
Becker, F.E.; Smolensky, L.A.
1988-07-19
A cyclone combustor apparatus contains a circular partition plate containing a central circular aperture is described. The partition plate divides the apparatus into a cylindrical precombustor chamber and a combustor chamber. A coal-water slurry is passed axially into the inlet end of the precombustor chamber, and primary air is passed tangentially into said chamber to establish a cyclonic air flow. Combustion products pass through the partition plate aperture and into the combustor chamber. Secondary air may also be passed tangentially into the combustor chamber adjacent the partition plate to maintain the cyclonic flow. Flue gas is passed axially out of the combustor chamber at the outlet end and ash is withdrawn tangentially from the combustor chamber at the outlet end. A first mixture of flue gas and ash may be tangentially withdrawn from the combustor chamber at the outlet end and recirculated to the axial inlet of the precombustor chamber with the coal-water slurry. A second mixture may be tangentially withdrawn from the outlet end and passed to a heat exchanger for cooling. Cooled second mixture is then recirculated to the axial inlet of the precombustor chamber. In another embodiment a single cyclone combustor chamber is provided with both the recirculation streams of the first mixture and the second mixture. 10 figs.
The anomalous transport of axial charge: topological vs non-topological fluctuations
Ioannis Iatrakis; Shu Lin; Yi Yin
2015-08-16
Axial charge imbalance is an essential ingredient in novel effects associated with chiral anomaly such as chiral magnetic effects (CME). In a non-Abelian plasma with chiral fermions, local axial charge can be generated a) by topological fluctuations which would create domains with non-zero winding number b) by conventional non-topological thermal fluctuations. We provide a holographic evaluations of medium's response to dynamically generated axial charge density in hydrodynamic limit and examine if medium's response depends on the microscopic origins of axial charge imbalance. We show a local domain with non-zero winding number would induce a non-dissipative axial current due to chiral anomaly. We illustrate holographically that a local axial charge imbalance would be damped out with the damping rate related to Chern-Simon diffusive constant. By computing chiral magnetic current in the presence of dynamically generated axial charge density, we found that the ratio of CME current over the axial charge density is independent of the origin of axial charge imbalance in low frequency and momentum limit. Finally, a stochastic hydrodynamic equation of the axial charge is formulated by including both types of fluctuations.
Non-stationary Riccati-type flows for incompressible 3D Navier-Stokes equations
Sergey V. Ershkov
2015-09-21
In fluid mechanics, a lot of authors have been executing their researches to obtain the analytical solutions of Navier-Stokes equations, even for 3D case of compressible gas flow or 3D case of non-stationary flow of incompressible fluid. But there is an essential deficiency of non-stationary solutions indeed. We explore the ansatz of derivation of non-stationary solution for the Navier-Stokes equations in the case of incompressible flow, which was suggested earlier. In general case, such a solution should be obtained from the mixed system of 2 Riccati ordinary differential equations (in regard to the time-parameter t). But we find an elegant way to simplify it to the proper analytical presentation of exact solution.
Axially staggered seed-blanket reactor-fuel-module construction. [LWBR
Cowell, G.K.; DiGuiseppe, C.P.
1982-10-28
A heterogeneous nuclear reactor of the seed-blanket type is provided wherein the fissile (seed) and fertile (blanket) nuclear fuels are segregated axially within each fuel element such that fissile and fertile regions occur in an alternating pattern along the length of the fuel element. Further, different axial stacking patterns are used for the fuel elements of at least two module types such that when modules of different types are positioned adjacent to one another, the fertile regions of the modules are offset or staggered. Thus, when a module of one type is surrounded by modules of the second type the fertile regions thereof will be surrounded on all sides by fissile material. This provides enhanced neutron communication both radially and axially, thereby resulting in greater power oscillation stability than other axial arrangements.
ARTICLE IN PRESS 1 Inferring flow types from dye patterns in macroporous soils
Weiler, Markus
2003; accepted 29 August 2003 6 Abstract 7 In this study, we exploit dye patterns to identify flow, and we think the concepts will have broad 18 application in soil science and infiltration research to compare the infiltration regimes of soils. 19 D 2003 Published by Elsevier B.V. 20 21 Keywords: Dye
Experimental Study of Heat Transfer and Flow Characteristics for a New Type of Air Heater
Zheng, H.; Fan, X.; Li, A.
2006-01-01
A new type air heater was developed, and an experimental set-up was built to analyze its characteristics. Within the Reynolds number from 2000 to 15000, the integrated characteristics in air heater channels with and without ...
The deep structure of Axial Volcano Michael West
West, Michael
available on Web #12;The deep structure of Axial Volcano IV. Magma Reservoir beneath Axial Volcano AxialThe deep structure of Axial Volcano Michael West Thesis defense, June 4, 2001 #12;Motivation What at Axial may be interpreted (NeMO, Neptune) #12;The deep structure of Axial Volcano IV. Magma Reservoir
Radio-frequency capacitive discharge with non-flow-type and droplet-jet electrolytic electrodes
Gaisin, A. F.; Abdullin, I. Sh.; Basyrov, R. Sh.; Khaziev, R. M.; Samitova, G. T.; Shakirova, E. F.
2014-12-15
Results are presented from experimental studies of the shape, structure, and spectral characteristics of an RF capacitive discharge operating between a droplet-jet electrolytic electrode and an electrolytic cell in air at pressures of P = 10{sup 3}–10{sup 5} Pa, as well as of a discharge burning between a copper rod and the surface of non-flow electrolyte at atmospheric pressure. It is found that, at voltages of U ? 3500 V, the multichannel discharge burning between the rod and the electrolyte (saturated solution of NaCl in technical water) surface transforms into a torch discharge. Specific features of the burning of a discharge with a droplet electrolytic electrode are investigated. Different forms of discharges burning on the surface of a copper tube and an electrolyte jet are revealed.
Modeling for control of rotating stall in high-speed multistage axial compressors
Feulner, M.R.; Hendricks, G.J.; Paduano, J.D.
1996-01-01
Using a two-dimensional compressible flow representation of axial compressor dynamics, a control-theoretic input-output model is derived, which is of general utility in rotating stall/surge active control studies. The derivation presented here begins with a review of the fluid dynamic model, which is a two-dimensional stage stacking technique that accounts for blade row pressure rise, loss, and deviation as well as blade row and interblade row compressible flow. This model is extended to include the effects of the upstream and downstream geometry and boundary conditions, and then manipulated into a transfer function form that dynamically relates actuator motion to sensor measurements. Key relationships in this input-output form are then approximated using rational polynomials. Further manipulation yields an approximate model in standard form for studying active control of rotating stall and surge. As an example of high current relevance, the transfer function from an array of jet actuators to an array of static pressure sensors is derived. Numerical examples are also presented, including a demonstration of the importance of proper choice of sensor and actuator locations, as well as a comparison between sensor types. Under a variety of conditions, it was found that sensor locations near the front of the compressor or in the downstream gap are consistently the best choices, based on a quadratic optimization criterion and a specific three-stage compressor model. The modeling and evaluation procedures presented here are a first step toward a rigorous approach to the design of active control systems for high-speed axial compressors.
An Unbroken Axial Vector Current Conservation Law
Rasulkhozha S. Sharafiddinov
2015-05-28
The mass, energy and momentum of the neutrino of a true flavor have an axial-vector nature. As a consequence, the left-handed truly neutral neutrino in an axial-vector field of emission can be converted into a right-handed one and vice versa. This predicts the unidenticality of masses, energies and momenta of neutrinos of the different components. Recognizing such a difference in masses, energies, momenta and accepting that the left-handed axial-vector neutrino and the right-handed antineutrino of true neutrality refer to long-lived C-odd leptons, and the right-handed truly neutral neutrino and the left-handed axial-vector antineutrino are of short-lived fermions of C-oddity, we would write a new CP-even Dirac equation taking into account the flavor symmetrical axial-vector mass, energy and momentum matrices. Their presence explains the spontaneous mirror symmetry violation, confirming that an axial-vector current conservation law has never violated. They reflect the availability of a mirror Minkowski space in which a neutrino is characterized by left as well as by right space-time coordinates. Therefore, it is not surprising that whatever the main purposes experiments about a quasielastic axial-vector mass say in favor of an axial-vector mirror Minkowski space-time.
Axial interaction free-electron laser
Carlsten, B.E.
1997-09-02
Electron orbits from a helical axial wiggler in an axial guide field are absolutely unstable as power is extracted from the particles. For off-axis beams an axial FEL mechanism exists when the axial electric field in a TM mode is wiggled to interact with the axial velocity of the electrons that form the beam. The interaction strength is comparable to that for helical FELs and is insensitive to beam orbit errors. The orbits for this mechanism are extremely stable in the absence of space charge and lead to high extraction efficiencies without particle phasing incoherence or interception. This interaction mechanism is suitable for use with intense annular electron beams for high power generation at microwave frequencies. 5 figs.
Axial interaction free-electron laser
Carlsten, Bruce E. (Los Alamos, NM)
1997-01-01
Electron orbits from a helical axial wiggler in an axial guide field are absolutely unstable as power is extracted from the particles. For off-axis beams an axial FEL mechanism exists when the axial electric field in a TM mode is wiggled to interact with the axial velocity of the electrons that form the beam. The interaction strength is comparable to that for helical FELs and is insensitive to beam orbit errors. The orbits for this mechanism are extremely stable in the absence of space charge and lead to high extraction efficiencies without particle phasing incoherence or interception. This interaction mechanism is suitable for use with intense annular electron beams for high power generation at microwave frequencies.
Experimental on two sensors combination used in horizontal pipe gas-water two-phase flow
Wu, Hao; Dong, Feng
2014-04-11
Gas-water two phase flow phenomenon widely exists in production and living and the measurement of it is meaningful. A new type of long-waist cone flow sensor has been designed to measure two-phase mass flow rate. Six rings structure of conductance probe is used to measure volume fraction and axial velocity. The calibration of them have been made. Two sensors have been combined in horizontal pipeline experiment to measure two-phase flow mass flow rate. Several model of gas-water two-phase flow has been discussed. The calculation errors of total mass flow rate measurement is less than 5% based on the revised homogeneous flow model.
L. Del Zanna; N. Bucciantini
2002-05-17
Multidimensional shock-capturing numerical schemes for special relativistic hydrodynamics (RHD) are computationally more expensive than their correspondent Euler versions, due to the nonlinear relations between conservative and primitive variables and to the consequent complexity of the Jacobian matrices (needed for the spectral decomposition in most of the approximate Riemann solvers of common use). Here an efficient and easy-to-implement three-dimensional (3-D) shock-capturing scheme for ideal RHD is presented. Based on the algorithms developed by P. Londrillo and L. Del Zanna ({\\em Astrophys. J.} 530, 508-524, 2000) for the non-relativistic magnetohydrodynamic (MHD) case, and having in mind its relativistic MHD extension (to appear in a forthcoming paper), the scheme uses high order (third) Convex Essentially Non-Oscillatory (CENO) finite difference interpolation routines and central-type averaged Riemann solvers, which do not make use of time-consuming characteristic decomposition. The scheme is very efficient and robust, and it gives results comparable to those obtained with more sophisticated algorithms, even in ultrarelativistic multidimensional test problems.
Damage detection for applications undergoing axial (membrane) response
Duffey, T.A. [Duffey (T.A.), Tijeras, NM (United States); Farrar, C.R.; Doebling, S.W. [Los Alamos National Lab., NM (United States)
1997-12-01
This paper extends and applies recently reported damage identification methods, previously utilized for flexural vibrations only, to axial-type vibrations. The methods are applied to an 8-DOF linear spring-mass system, which models a multi-degree-of-freedom axial or membrane system. The goal of the work is to detect damage (as indicated by reduction in stiffness of one or more of the elements) as well as to locate the damage elements. Two damage detection methods were investigated--the change-in-flexibility method and the damage-index method. Both were found to successfully locate the damaged element(s) for 10% reduction in element stiffness. The change-in-flexibility method indicated damage location even when only a limited number of lower modes were included.
A study of spike and modal stall phenomena in a low-speed axial compressor
Camp, T.R.; Day, I.J.
1998-07-01
This paper presents a study of stall inception mechanisms in a low-speed axial compressor. Previous work has identified two common flow breakdown sequences, the first associated with a short length-scale disturbance known as a spike, and the second with a longer length-scale disturbance known as a modal oscillation. In this paper the physical differences between these two mechanisms are illustrated with detailed measurements. Experimental results are also presented that relate the occurrence of the two stalling mechanisms to the operating conditions of the compressor. It is shown that the stability criteria for the two disturbances are different: Long length-scale disturbances are related to a two-dimensional instability of the whole compression system, while short length-scale disturbances indicate a three-dimensional breakdown of the flow-field associated with high rotor incidence angles. Based on the experimental measurements, a simple model is proposed that explains the type of stall inception pattern observed in a particular compressor. Measurements from a single-stage low-speed compressor and from a multistage high-speed compressor are presented in support of the model.
Performance limits of axial turbomachine stages
Hall, David Kenneth
2011-01-01
This thesis assesses the limits of stage efficiency for axial compressor and turbine stages. A stage model is developed, consisting of a specified geometry and a surface velocity distribution with turbulent boundary layers. ...
Chiral corrections to hyperon axial form factors
Jiang Fujiun; Tiburzi, B. C.
2008-05-01
We study the complete set of flavor-changing hyperon axial-current matrix elements at small momentum transfer. Using partially quenched heavy baryon chiral perturbation theory, we derive the chiral and momentum behavior of the axial and induced pseudoscalar form factors. The meson pole contributions to the latter posses a striking signal for chiral physics. We argue that the study of hyperon axial matrix elements enables a systematic lattice investigation of the efficacy of three-flavor chiral expansions in the baryon sector. This can be achieved by considering chiral corrections to SU(3) symmetry predictions, and their partially quenched generalizations. In particular, despite the presence of eight unknown low-energy constants, we are able to make next-to-leading order symmetry breaking predictions for two linear combinations of axial charges.
Isosinglet Versus Octet Scalar Axial Current
Kirchbach, M
1998-01-01
The flavor SU(3)_f group symmetry of QCD is systematically considered as the heavy charmed quark limit of SU(4)_f. Within that scheme the introduction of an octet axial current suggests physical manifestations of the SU(4)_f flavor singlet axial current. As long as the latter is known to be nonobservable due to instanton effects, Gell-Mann's choice for the realization of the su(3)_f algebra does not apply to the particular case of neutral axial currents. Rather, Weyl's choice for the SU(4)_f generators has to be used which leads to a neutral strong axial current having same structure as the weak one. According to that, the light quark flavors participate the neutral axial vector current exclusively via the third component of its isotriplet part, while the strange quarks create a purely isosinglet component. An octet axial current part is absent. As a consequence, the contact gradient coupling of octet scalar pseudoscalar mesons to the nucleon will be an isosinglet rather than an octet scalar. It will, therefo...
An Unbroken Axial Vector Current Conservation Law
Sharafiddinov, Rasulkhozha S
2015-01-01
The mass, energy and momentum of the neutrino of a true flavor have an axial-vector nature. As a consequence, the left-handed truly neutral neutrino in an axial-vector field of emission can be converted into a right-handed one and vice versa. This predicts the unidenticality of masses, energies and momenta of neutrinos of the different components. Recognizing such a difference in masses, energies, momenta and accepting that the left-handed axial-vector neutrino and the right-handed antineutrino of true neutrality refer to long-lived C-odd leptons, and the right-handed truly neutral neutrino and the left-handed axial-vector antineutrino are of short-lived fermions of C-oddity, we would write a new CP-even Dirac equation taking into account the flavor symmetrical axial-vector mass, energy and momentum matrices. Their presence explains the spontaneous mirror symmetry violation, confirming that an axial-vector current conservation law has never violated. They reflect the availability of a mirror Minkowski space i...
CALTECH ASCI TECHNICAL REPORT 130 Axial motion and scalar transport in stretched spiral vortices
Barr, Al
of Technology, Pasadena, California 91125 T. S. Lundgren Department of Aerospace Engineering and Mechanics-vortex flow. The dominant term in the velocity energy spectrum contributed by the axial velocity is found of the azimuthal velocity. This gives a k 7/3 spectrum at large wave numbers, compared to the k 5/3 component
Scalar Resonances in Axially Symmetric Spacetimes
Ignacio F. Ranea-Sandoval; Héctor Vucetich
2015-03-12
We study properties of resonant solutions to the scalar wave equation in several axially symmetric spacetimes. We prove that non-axial resonant modes do not exist neither in the Lanczos dust cylinder, the $(2+1)$ extreme BTZ spacetime nor in a class of simple rotating wormhole solutions. Moreover, we find unstable solutions to the wave equation in the Lanczos dust cylinder and in the $r^2 <0$ region of the extreme $(2+1)$ BTZ spacetime, two solutions that possess closed timelike curves. Similarities with previous results obtained for the Kerr spacetime are explored.
Skyrme RPA for spherical and axially symmetric nuclei
Anton Repko; Jan Kvasil; V. O. Nesterenko; P. -G. Reinhard
2015-10-05
Random Phase Approximation (RPA) is the basic method for calculation of excited states of nuclei over the Hartree-Fock ground state, suitable also for energy density functionals (EDF or DFT). We developed a convenient formalism for expressing densities and currents in a form of reduced matrix elements, which allows fast calculation of spectra for spherical nuclei. All terms of Skyrme functional were taken into account, so it is possible to calculate electric, magnetic and vortical/toroidal/compression transitions and strength functions of any multipolarity. Time-odd (spin) terms in Skyrme functional become important for magnetic M1 and isovector toroidal E1 transitions. It was also found that transition currents in pygmy region (low-lying part of E1 resonance) exhibit isoscalar toroidal flow, so the previously assumed picture of neutron-skin vibration is not the only mechanism present in pygmy transitions. RPA calculations with heavy axially-symmetric nuclei now become feasible on ordinary PC. Detailed formulae for axial Skyrme RPA are given. Some numerical results are shown in comparison with the approximate approach of separable RPA, previously developed in our group for fast calculation of strength functions.
Co-axial, high energy gamma generator
Reijonen, Jani Petteri (Princeton, NJ); Gicquel, Frederic (Pennington, NJ)
2011-08-16
A gamma ray generator includes an ion source in a first chamber. A second chamber is configured co-axially around the first chamber at a lower second pressure. Co-axially arranged plasma apertures separate the two chambers and provide for restricted passage of ions and gas from the first to the second chamber. The second chamber is formed by a puller electrode having at least one long channel aperture to draw ions from the first chamber when the puller electrode is subject to an appropriate applied potential. A plurality of electrodes rings in the third chamber in third pressure co-axially surround the puller electrode and have at least one channel corresponding to the at least one puller electrode aperture and plasma aperture. The electrode rings increase the energy of the ions to a selected energy in stages in passing between successive pairs of the electrodes by application of an accelerating voltage to the successive pairs of accelerator electrodes. A target disposed co-axially around the plurality of electrodes receives the beam of accelerated ions, producing gamma rays.
Dykin, V.; Pazsit, I.
2012-07-01
A possibility to reconstruct the axial void profile from the simulated in-core neutron noise which is caused by density fluctuations in a Boiling Water Reactor (BWR) heated channel is considered. For this purpose, a self-contained model of the two-phase flow regime is constructed which has quantitatively and qualitatively similar properties to those observed in real BWRs. The model is subsequently used to simulate the signals of neutron detectors induced by the corresponding perturbations in the flow density. The bubbles are generated randomly in both space and time using Monte-Carlo techniques. The axial distribution of the bubble production is chosen such that the mean axial void fraction and void velocity follow the actual values of BWRs. The induced neutron noise signals are calculated and then processed by the standard signal analysis methods such as Auto-Power Spectral Density (APSD) and Cross-Power Spectral Density (CPSD). Two methods for axial void and velocity profiles reconstruction are discussed: the first one is based on the change of the break frequency of the neutron auto-power spectrum with axial core elevation, while the second refers to the estimation of transit times of propagating steam fluctuations between different axial detector positions. This paper summarizes the principles of the model and presents a numerical testing of the qualitative applicability to estimate the required parameters for the reconstruction of the void fraction profile from the neutron noise measurements. (authors)
Skyrme RPA for spherical and axially symmetric nuclei
Repko, Anton; Nesterenko, V O; Reinhard, P -G
2015-01-01
Random Phase Approximation (RPA) is the basic method for calculation of excited states of nuclei over the Hartree-Fock ground state, suitable also for energy density functionals (EDF or DFT). We developed a convenient formalism for expressing densities and currents in a form of reduced matrix elements, which allows fast calculation of spectra for spherical nuclei. All terms of Skyrme functional were taken into account, so it is possible to calculate electric, magnetic and vortical/toroidal/compression transitions and strength functions of any multipolarity. Time-odd (spin) terms in Skyrme functional become important for magnetic M1 and isovector toroidal E1 transitions. It was also found that transition currents in pygmy region (low-lying part of E1 resonance) exhibit isoscalar toroidal flow, so the previously assumed picture of neutron-skin vibration is not the only mechanism present in pygmy transitions. RPA calculations with heavy axially-symmetric nuclei now become feasible on ordinary PC. Detailed formul...
Reducing axial offset and improving stability in PWRs by using uraniumethorium fuel
Demazière, Christophe
Reducing axial offset and improving stability in PWRs by using uraniumethorium fuel Cheuk Wah Lau a that a new type uraniumethorium (UeTh) based fuel assembly could be used to achieve a more homogenous radial that a core containing UeTh fuel assemblies also reduces the AO and improves the core stability
Chiral corrections and the axial charge of the delta
Jiang Fujiun; Tiburzi, Brian C.
2008-07-01
Chiral corrections to the delta axial charge are determined using heavy baryon chiral perturbation theory. Knowledge of this axial coupling is necessary to assess virtual-delta contributions to nucleon and delta observables. We give isospin relations useful for a lattice determination of the axial coupling. Furthermore, we detail partially quenched chiral corrections, which are relevant to address partial quenching and/or mixed action errors in lattice calculations of the delta axial charge.
Abdou, Mohamed
and thus the permeation rate. To reduce the stress in the FCI structure material, a PES is utilized 90095, USA, zhjbook@gmail.com A SiC-based flow channel insert (FCI) is used as an electrical and thermal the tritium transfer behavior and loss rate. Therefore it is important to examine the tritium loss rate
Piping inspection carriage having axially displaceable sensor
Zollinger, William T. (Martinez, GA); Treanor, Richard C. (Augusta, GA)
1994-01-01
A pipe inspection instrument carriage for use with a pipe crawler for performing internal inspections of piping surfaces. The carriage has a front leg assembly, a rear leg assembly and a central support connecting the two assemblies and for mounting an instrument arm having inspection instruments. The instrument arm has a y-arm mounted distally thereon for axially aligning the inspection instrumentation and a mounting block, a linear actuator and axial movement arm for extending the inspection instruments radially outward to operably position the inspection instruments on the piping interior. Also, the carriage has a rotation motor and gear assembly for rotating the central support and the front leg assembly with respect to the rear leg assembly so that the inspection instruments azimuthally scan the piping interior. The instrument carriage allows performance of all piping inspection operations with a minimum of moving parts, thus decreasing the likelihood of performance failure.
Piping inspection carriage having axially displaceable sensor
Zollinger, W.T.; Treanor, R.C.
1994-12-06
A pipe inspection instrument carriage is described for use with a pipe crawler for performing internal inspections of piping surfaces. The carriage has a front leg assembly, a rear leg assembly and a central support connecting the two assemblies and for mounting an instrument arm having inspection instruments. The instrument arm has a Y-arm mounted distally thereon for axially aligning the inspection instrumentation and a mounting block, a linear actuator and axial movement arm for extending the inspection instruments radially outward to operably position the inspection instruments on the piping interior. Also, the carriage has a rotation motor and gear assembly for rotating the central support and the front leg assembly with respect to the rear leg assembly so that the inspection instruments azimuthally scan the piping interior. The instrument carriage allows performance of all piping inspection operations with a minimum of moving parts, thus decreasing the likelihood of performance failure. 4 figures.
Dorsett, Kenneth Merle
1993-01-01
A flow visualization measurement scheme was validated in flight. Strake vortex trajectories and axial core velocities were determined using pulsed smoke and high speed video. A gothic strake, operated at an angle of attack of 220 and a Reynolds...
An analytical model of axial compressor off-design performance
Camp, T.R.; Horlock, J.H. . Whittle Lab.)
1994-07-01
An analysis is presented of the off-design performance of multistage axial-flow compressors. It is based on an analytical solution, valid for small perturbations in operating conditions from the design point, and provides an insight into the effects of choices made during the compressor design process on performance and off-design stage matching. It is shown that the mean design value of stage loading coefficient ([psi] = [Delta]h[sub 0]/U[sup 2]) has a dominant effect on off-design performance, whereas the stage-wise distribution of stage loading coefficient and the design value of flow coefficient have little influence. The powerful effects of variable stator vanes on stage-matching are also demonstrated and these results are shown to agree well with previous work. The slope of the working line of a gas turbine engine, overlaid on overall compressor characteristics, is shown to have a strong effect on the off-design stage-matching through the compressor. The model is also used to analyze design changes to the compressor geometry and to show how errors in estimates of annulus blockage, decided during the design process, have less effect on compressor performance than has previously been thought.
Gravitational waves from a test particle scattered by a neutron star: Axial mode case
Kazuhiro Tominaga; Motoyuki Saijo; Kei-ichi Maeda
1999-09-20
Using a metric perturbation method, we study gravitational waves from a test particle scattered by a spherically symmetric relativistic star. We calculate the energy spectrum and the waveform of gravitational waves for axial modes. Since metric perturbations in axial modes do not couple to the matter fluid of the star, emitted waves for a normal neutron star show only one peak in the spectrum, which corresponds to the orbital frequency at the turning point, where the gravitational field is strongest. However, for an ultracompact star (the radius $R \\lesssim 3M$), another type of resonant periodic peak appears in the spectrum. This is just because of an excitation by a scattered particle of axial quasinormal modes, which were found by Chandrasekhar and Ferrari. This excitation comes from the existence of the potential minimum inside of a star. We also find for an ultracompact star many small periodic peaks at the frequency region beyond the maximum of the potential, which would be due to a resonance of two waves reflected by two potential barriers (Regge-Wheeler type and one at the center of the star). Such resonant peaks appear neither for a normal neutron star nor for a Schwarzschild black hole. Consequently, even if we analyze the energy spectrum of gravitational waves only for axial modes, it would be possible to distinguish between an ultracompact star and a normal neutron star (or a Schwarzschild black hole).
Multi-cylinder axial stratified charging studied
Not Available
1982-05-01
Charge stratification can be obtained inside a noncylindrical combustion chamber of a fuel injected multi-cylinder engine by properly timing the injection event, directing the fuel spray into the inlet port, and imparting swirl to the inlet charge. A production 1.8-liter engine modified to operate as an axially stratified-charge engine showed 50% improvement in combustion stability, 3.5% lower fuel consumption, five research octane number lower octane requirement, and increased tolerance to dilute mixtures when compared with an unmodified engine.
Yang, Gang; Olson, J.C.; Pu, R.; Vyas, G.N.
1995-10-01
Serological assays are routinely used in the laboratory diagnosis of human immunodeficiency virus type-1 (HrV-1) infection, but the polymerase chain reaction (PCR) is ultimately the most sensitive and direct method for establishing definitive diagnosis. As an alternative to the conventional radioactive PCR procedure we have developed and evaluated a pair of rapid nonradioisotopic flow cytometric detection methods. Using heminested PCR we directly incorporated fluorescein-12-dUTP (fluo-dUTP) or digoxigenin-11-dUTP (dig-dUTP) into the PCR-amplicons. The labeled amplicons were hybridized with biotinylated antisense and sense probes, followed by capture of the hybrid DNA using streptavidin-coated beads which were finally analyzed in a flow cytometer by (1) direct detection of the fluorescence intensity of the amplicons incorporating fluo-dUTP and (2) immunodetection of the amplicons incorporating dig-dUTP by anti-digoxigenin IgG labeled with fluorescein isothiocyanate (FITC). Although both assays were functionally comparable with radiolabeled probe in reliably detecting as low as five copies of HIV-1 proviral DNA sequences, the immunodetection of dig-dUTP consistently yielded higher mean channel fluorescence and gave a stable signal over an extended period of 12-14 weeks. In testing a panel of 20 pedigreed PBMC specimens from blood donors with or without HIV-1 infection, the results of both flow cytometric assays were identical with those of the conventional radioactive procedure. Therefore, we conclude that the dig-dUTP incorporation in amplicons, hybridization with a pair of sense-antisense biotinylated probes and immunodetection of hybrids by flow cytometric analyses is the nonisotopic method of choice for PCR-diagnosis of HIV-1 infection. 21 refs., 2 figs., 4 tabs.
Gordon, Kenneth A. (Kenneth Andrew), 1970-
1999-01-01
The effects of two types of flow nonuniformity on stall inception behavior were assessed with linearized stability analyses of two compressor flow models. Response to rotating tip clearance asymmetries induced by a whirling ...
Development of a full-flow burner regeneration type diesel particulate filter using SiC honeycomb
Okazoe, Hiroshi; Shimizu, Kenji; Watanabe, Yoshito; Santiago, E.; Kugland, P.; Ruth, W.
1996-09-01
A diesel particulate filter (DPF) for city buses was developed that combines a SiC filter and a full-now type burner for regeneration. Filter crack problems were averted by suppressing the peak temperature inside the filter to under 900 C. This was done by setting the maximum tolerable amount of collected particulate mass before regeneration at 50 g and controlling the burner so as to increase the regeneration gas temperature slowly up to a set value. This DPF was retrofitted to a Tokyo metropolitan bus to conduct a field test. The field test has been under way for half a year without any trouble or deterioration of system performance.
Weyant, Anja; Wood-Vasey, W. Michael [Pittsburgh Particle physics, Astrophysics, and Cosmology Center (PITT PACC), Physics and Astronomy Department, University of Pittsburgh, Pittsburgh, PA 15260 (United States); Allen, Lori; Joyce, Richard; Matheson, Thomas [National Optical Astronomy Observatory, 950 North Cherry Avenue, Tucson, AZ 85719 (United States); Garnavich, Peter M. [Department of Physics, 225 Nieuwland Science Hall, Notre Dame, IN 46556 (United States); Jha, Saurabh W., E-mail: anw19@pitt.edu [Department of Physics and Astronomy, Rutgers, the State University of New Jersey, 136 Frelinghuysen Road, Piscataway, NJ 08854 (United States)
2014-04-01
We present 13 Type Ia supernovae (SNe Ia) observed in the rest-frame near-infrared (NIR) from 0.02 < z < 0.09 with the WIYN High-resolution Infrared Camera on the WIYN 3.5 m telescope. With only one to three points per light curve and a prior on the time of maximum from the spectrum used to type the object, we measure an H-band dispersion of spectroscopically normal SNe Ia of 0.164 mag. These observations continue to demonstrate the improved standard brightness of SNe Ia in an H band, even with limited data. Our sample includes two SNe Ia at z ? 0.09, which represent the most distant rest-frame NIR H-band observations published to date. This modest sample of 13 NIR SNe Ia represent the pilot sample for {sup S}weetSpot{sup —}a 3 yr NOAO Survey program that will observe 144 SNe Ia in the smooth Hubble flow. By the end of the survey we will have measured the relative distance to a redshift of z ? 0.05%-1%. Nearby Type Ia supernova (SN Ia) observations such as these will test the standard nature of SNe Ia in the rest-frame NIR, allow insight into the nature of dust, and provide a critical anchor for future cosmological SN Ia surveys at higher redshift.
Nuclear Axial Currents in Chiral Effective Field Theory
Baroni, A; Pastore, S; Schiavilla, R; Viviani, M
2015-01-01
Two-nucleon axial charge and current operators are derived in chiral effective field theory up to one loop. The derivation is based on time-ordered perturbation theory, and accounts for cancellations between the contributions of irreducible diagrams and the contributions due to non-static corrections from energy denominators of reducible diagrams. Ultraviolet divergencies associated with the loop corrections are isolated in dimensional regularization. The resulting axial current is finite and conserved in the chiral limit, while the axial charge requires renormalization. A complete set of contact terms for the axial charge up to the relevant order in the power counting is constructed.
An analysis of axial compressor fouling and a blade cleaning method
Tarabrin, A.P.; Schurovsky, V.A.; Bodrov, A.I.; Stalder, J.P.
1998-04-01
The paper describes the phenomenon of axial compressor fouling due to aerosols contained in the air. Key parameters having effect on the level of fouling are determined. A mathematical model of a progressive compressor fouling using the stage-by-stage calculation method is developed. Calculation results on the influence of fouling on the compressor performance are presented. A new index of sensitivity of axial compressors to fouling is suggested. The paper gives information about Turbotect`s deposit cleaning method of compressor blading and the results of its application on an operating industrial gas turbine. Regular on-line and off-line washings of the compressor flow path made it possible to maintain a high level of engine efficiency and output.
Makhkamov, K.K.; Ingham, D.B.
1999-11-01
A theoretical study on the air flow and temperature in the heat receiver, affected by free convection, of a Stirling Engine for a Dish/Stirling Engine Power System is presented. The standard {kappa}-{epsilon} turbulence model for the fluid flow has been used and the boundary conditions employed were obtained using a second level mathematical model of the Stirling Engine working cycle. Physical models for the distribution of the solar insolation from the Concentrator on the bottom and side walls of the cavity-type heat receiver have been taken into account. The numerical results show that most of the heat losses in the receiver are due to re-radiation from the cavity and conduction through the walls of the cavity. It is in the region of the boundary of the input window of the heat receiver where there is a sensible reduction in the temperature in the shell of the heat exchangers and this is due to the free convection of the air. Further, the numerical results show that convective heat losses increase with decreasing tilt angle.
The Shaft Torque of a Tandem Axial-Piston Pump
Manring, Noah D.
The Shaft Torque of a Tandem Axial- Piston Pump Noah D. Manring Viral S. Mehta Mechanical of this study is to identify the best indexed position of two rotating groups within a tandem axial-piston pump characteristics of the pump, other vibration aspects of the machine are also expected to be reduced. In particular
Clement, Prabhakar
Pipe Flow System Design Holly Guest #12;Problem · An engineer is asked to compute the flow rate · Flow type: Turbulent or Laminar flow · Flow rate · Frictional head loss · Optimal diameters if a pump · = - ( . + . ) · f = friction factor · = relative roughness = · = Reynolds Number = · Laminar flow: 2000
Effects of inlet geometries on flow recirculation in an axial-flow pump
Alpan, Kenan
1984-01-01
, e) hydraulic surging on the suction side, f) intense vortices with high velocities resulting with high wall static pressures at the pump inlet, g) formation of intense cavitation, h) severe pressure pulsations and noise, i) loss of energy...) mechanical seal damage. Despite elaborate research in the field of cavitation no study has been done to determine its interaction with recirculation. It is believed that they both contribute to the blade erosion. Homogenous liquids such as water are more...
Torsional Alfven Waves in Solar Magnetic Flux Tubes of Axial Symmetry
Murawski, K; Musielak, Z E; Srivastava, A K; Kraskiewicz, J
2015-01-01
Aims: Propagation and energy transfer of torsional Alfv\\'en waves in solar magnetic flux tubes of axial symmetry is studied. Methods: An analytical model of a solar magnetic flux tube of axial symmetry is developed by specifying a magnetic flux and deriving general analytical formulae for the equilibrium mass density and a gas pressure. The main advantage of this model is that it can be easily adopted to any axisymmetric magnetic structure. The model is used to simulate numerically the propagation of nonlinear Alfv\\'en waves in such 2D flux tubes of axial symmetry embedded in the solar atmosphere. The waves are excited by a localized pulse in the azimuthal component of velocity and launched at the top of the solar photosphere, and they propagate through the solar chromosphere, transition region, and into the solar corona. Results: The results of our numerical simulations reveal a complex scenario of twisted magnetic field lines and flows associated with torsional Alfv\\'en waves as well as energy transfer to t...
A microscopic derivation of nuclear collective rotation-vibration model, axially symmetric case
Parviz Gulshani
2015-05-12
We derive a microscopic version of the successful phenomenological hydrodynamic model of Bohr-Davydov-Faessler-Greiner for collective rotation-vibration motion of an axially symmetric deformed nucleus. The derivation is not limited to small oscillation amplitude. The nuclear Schrodinger equation is canonically transformed the to collective co-ordinates, which is then linearized using a constrained variational method. The associated constraints are imposed on the wavefunction rather than on the particle co-ordinates. The approach yields three self-consistent, time-reversal invariant, cranking-type Schrodinger equations for the rotation-vibration and intrinsic motions, and a self-consistency equation. For harmonic oscillator mean-field potentials, these equations are solved in closed forms and applied to the ground-state rotational bands in some axially-symmetric nuclei. The results are compared with the measured data.
Phung, Anh Ngoc
1995-01-01
, bristle diameter, bristle free length, seal backplate diameter, and lift-off gap. Numerical flow visualization illustrates the three-dimensional flow field, showing the circumferential, axial, and radial components of velocity near the bristle surface...
Optimization of the axial power shape in pressurized water reactors
Malik, Mushtaq Ahmad
1981-01-01
Analytical and numerical methods have been applied to find the optimum axial power profile in a PWR with respect to uranium utilization. The preferred shape was found to have a large central region of uniform power density, ...
Applications of axial and radial compressor dynamic system modeling
Spakovszky, Zoltán S. (Zoltán Sándor), 1972-
2001-01-01
The presented work is a compilation of four different projects related to axial and centrifugal compression systems. The projects are related by the underlying dynamic system modeling approach that is common in all of them. ...
Design of high temperature high speed electromagnetic axial thrust bearing
Mohiuddin, Mohammad Waqar
2002-01-01
The National Aeronautics and Space Administration (NASA) is researching the magnetic bearings to use it as a better alternative to conventional bearings. This research was to develop an axial thrust electromagnetic bearing for high performance jet...
Hyperon axial charges in two-flavor chiral perturbation theory
Jiang Fujiun; Tiburzi, Brian C.
2009-10-01
We use two-flavor heavy baryon chiral perturbation theory to investigate the isovector axial charges of the spin one-half hyperons. Expressions for these hyperon axial charges are derived at next-to-leading order in the chiral expansion. We utilize phenomenological and lattice QCD inputs to assess the convergence of the two-flavor theory, which appears to be best for cascades.
Balanced Flow Geostrophic, Inertial, Gradient, and Cyclostrophic Flow
Hennon, Christopher C.
Balanced Flow Geostrophic, Inertial, Gradient, and Cyclostrophic Flow The types of atmospheric flows describe here have the following characteristics: 1) Steady state (meaning that the flows do surfaces) These are "idealized" flows, created by balances of horizontal forces. They provide a qualitative
Design and market considerations for axial flux superconducting electric machine design
Ainslie, Mark D; Shaw, Robert; Dawson, Lewis; Winfield, Andy; Steketee, Marina; Stockley, Simon
2013-01-01
In this paper, the authors investigate a number of design and market considerations for an axial flux superconducting electric machine design that uses high temperature superconductors. This work was carried out as part of the University of Cambridge's Centre for Entrepreneurial Learning ETECH Project programme, designed to accelerate entrepreneurship and diffusion of innovations based on early stage and potentially disruptive technologies from the University. The axial flux machine design is assumed to utilise high temperature superconductors in both wire (stator winding) and bulk (rotor field) forms, to operate over a temperature range of 65-77 K, and to have a power output in the range from 10s of kW up to 1 MW (typical for axial flux machines), with approximately 2-3 T as the peak trapped field in the bulk superconductors. The authors firstly investigate the applicability of this type of machine as a generator in small- and medium-sized wind turbines, including the current and forecasted market and pricin...
Impact of axial diffusion on nitric oxide exchange in the lungs
George, Steven C.
Impact of axial diffusion on nitric oxide exchange in the lungs HYE-WON SHIN1 AND STEVEN C. GEORGE1, Hye-Won, and Steven C. George. Impact of axial diffusion on nitric oxide exchange in the lungs. J Appl of the lungs, but neglects axial diffusion. We incorporated axial diffusion into a one-dimensional trumpet
Flow conditioner for fuel injector for combustor and method for low-NO.sub.x combustor
Dutta, Partha; Smith, Kenneth O.; Ritz, Frank J.
2013-09-10
An injector for a gas turbine combustor including a catalyst coated surface forming a passage for feed gas flow and a channel for oxidant gas flow establishing an axial gas flow through a flow conditioner disposed at least partially within an inner wall of the injector. The flow conditioner includes a length with an interior passage opening into upstream and downstream ends for passage of the axial gas flow. An interior diameter of the interior passage smoothly reduces and then increases from upstream to downstream ends.
McFarland, Andrew R. (College Station, TX); Rodgers, John C. (Santa Fe, NM); Ortiz, Carlos A. (Bryan, TX); Nelson, David C. (Santa Fe, NM)
1994-01-01
Elbow mass flow meter. The present invention includes a combination of an elbow pressure drop generator and a shunt-type mass flow sensor for providing an output which gives the mass flow rate of a gas that is nearly independent of the density of the gas. For air, the output is also approximately independent of humidity.
Pinch instabilities in Taylor-Couette flow Dima Shalybkov*
or Hartmann number exceeds some critical value, destabilizes every flow including flows which are stable. The interval length is zero for a critical Hartmann number and increases with an increasing Hartmann number. The critical Hartmann numbers and length of the unstable axial wave number intervals are the same for every
An Axial Vector Nature of a Neutrino with an Electroweak Mass
Rasulkhozha S. Sharafiddinov
2011-11-09
A classification of elementary particles with respect to C-operation admits the existence of truly neutral types of fermions. Among them one can find both a Dirac and a Majorana neutrinos of an electroweak nature. Their mass includes the electric and weak parts, in the presence of which a neutrino has the anapole charge, charge radius and electric dipole moment. They constitute the paraneutrino of true neutrality, for example, at the neutrino interaction with a spinless nucleus of an axial-vector current. We derive the united equations which relate the structural components of mass to anapole, charge radius and electric dipole of each truly neutral neutrino at the level of flavour symmetry. Such a principle can explain the C-noninvariant nature of neutrinos and fields in the framework of constancy law of the size implied from the multiplication of a weak mass of the C-odd neutrino by its electric mass. From this point of view, all neutrinos of C-antisymmetricality regardless of the difference in masses of an axial-vector character, possess the same anapole with his radius as well as the identical electric dipole. Their analysis together with earlier measurements of an electric dipole moment of neutrino gives the right to accept not only the existence of truly neutral types of Dirac neutrinos and fields but also the availability of mass structure in them as the one of experimentally established facts.
Axial symmetries in lattice QCD with Kaplan fermions
Vadim Furman; Yigal Shamir
1994-11-23
This paper develops in detail a lattice definition of QCD based on the chiral defect fermions recently introduced by Kaplan. The revised version provides missing technical details in the proof that non-singlet axial symmetries become exact in the limit of an infinite fifth dimension. Also several minor errors are corrected.
Neutrino Physics and Nuclear Axial Two-Body Interactions
A. B. Balantekin; H. Yuksel
2004-11-06
We consider the counter-term describing isoscalar axial two-body currents in the nucleon-nucleon interaction, L1A, in the effective field theory approach. We determine this quantity using the solar neutrino data. We investigate the variation of L1A when different sets of data are used.
Tube bending with axial pull and internal pressure
Agarwal, Rohit
2004-09-30
such as axial force and internal pressure which can be used to achieve better shape control and thickness distribution of the tube. Based on plasticity theories, an analytical model is developed to predict cross section distortion and thickness change of tubes...
Mincey, J.F.
1980-01-01
The experimental and COBRA-IV computational data presented in this report confirm that increased pressure losses, induced by the steady-state axial flow of water exterior to deformed Multirod Burst Test (MRBT) bundles B-1 and B-2, may be closely predicted using a bundle-averaged approach for describing flow channel restrictions. One anomaly that was encountered using this technique occurred while modeling the B-2 flow test data near a severe channel restriction: the COBRA-IV results tended to underestimate experimental pressure losses.
Axial force imparted by a current-free magnetically expanding plasma
Takahashi, Kazunori [Space Plasma, Power and Propulsion Laboratory, Research School of Physics and Engineering, Australian National University, Canberra ACT 0200 (Australia); Department of Electrical Engineering and Computer Science, Iwate University, Morioka 020-8551 (Japan); Lafleur, Trevor; Charles, Christine; Alexander, Peter; Boswell, Rod W. [Space Plasma, Power and Propulsion Laboratory, Research School of Physics and Engineering, The Australian National University, Canberra ACT 0200 (Australia)
2012-08-15
The axial force imparted from a magnetically expanding, current-free, radiofrequency plasma is directly measured. For an argon gas flow rate of 25 sccm and an effective rf input power of {approx}800W, a maximum force of {approx}6mN is obtained; {approx}3mN of which is transmitted via the expanding magnetic field. The measured forces are reasonably compared with a simple fluid model associated with the measured electron pressure. The model suggests that the total force is the sum of an electron pressure inside the source and a Lorentz force due to the electron diamagnetic drift current and the applied radial magnetic field. It is shown that the Lorentz force is greatest near the magnetic nozzle surface where the radial pressure gradient is largest.
Determing Degradation Of Fiberboard In The 9975 Shipping Package By Measuring Axial Gap
Hackney, E. R.; Dougherty, W. L.; Dunn, K. A.; Stefek, T. M
2013-08-01
Currently, thousands of model 9975 transportation packages are in use by the US Department of Energy (DOE); the design of which has been certified by DOE for shipment of Type B radioactive and fissile materials in accordance with Part 71, Title 10 Code of Federal Regulations (CFR), or 10 CFR 71, Packaging and Transportation of Radioactive Material. These transportation packages are also approved for the storage of DOE-STD-3013 containers at the Savannah River Site (SRS). As such, the 9975 has been continuously exposed to the service environment for a period of time greater than the approved transportation service life. In order to ensure the material integrity as specified in the safety basis, an extensive surveillance program is in place in K-Area Complex (KAC) to monitor the structural and thermal properties of the fiberboard of the 9975 shipping packages. The surveillance approach uses a combination of Non-Destructive Examination (NDE) field surveillance and Destructive Examination (DE) lab testing to validate the 9975 performance assumptions. The fiberboard in the 9975 is credited with thermal insulation, criticality control and resistance to crushing. During surveillance monitoring in KAC, an increased axial gap of the fiberboard was discovered on selected items packaged at Rocky Flats Environmental Technology Site (RFETS). Many of these packages were later found to contain excess moisture. Savannah River National Laboratory (SRNL) testing has resulted in a better understanding of the relationship between the fiberboard moisture level and compaction of the fiberboard under storage conditions and during transport. In laboratory testing, the higher moisture content has been shown to correspond to higher total compaction of fiberboard material and compaction rate. The fiberboard height is reduced by compression of the layers. This change is observed directly in the axial gap between the flange and the air shield. The axial gap measurement is made during the pre-use inspection or during the annual recertification process and is a screening measurement for changes in the fiberboard.
Active stabilization of rotating stall in a three-stage axial compressor
Haynes, J.M.; Hendricks, G.J.; Epstein, A.H. . Gas Turbine Lab.)
1994-04-01
A three-stage, low-speed axial research compressor has been actively stabilized by damping low-amplitude circumferentially traveling waves, which can grow into rotating stall. Using a circumferential array of hot-wire sensors, and an array of high-speed individually positioned control vanes as the actuator, the first and second spatial harmonics of the compressor were stabilized down to a characteristic slope of 0.9, yielding an 8 percent increase in operating flow range. Stabilization of the third spatial harmonic did not alter the stalling flow coefficient. The actuators were also used open loop to determine the forced response behavior of the compressor. A system identification procedure applied to the forced response data then yielded the compressor transfer function. The Moore-Greitzer two-dimensional stability model was modified as suggested by the measurements to include the effect of blade row time lags on the compressor dynamics. This modified Moore-Greitzer model was then used to predict both the open and closed-loop dynamic response of the compressor. The model predictions agreed closely with the experimental results. In particular, the model predicted both the mass flow at stall without control and the design parameters needed by, and the range extension realized from, active control.
Liquid metal flow encasing a magnetic cavity A. B. Hassam,a)
Lathrop, Daniel P.
Liquid metal flow encasing a magnetic cavity A. B. Hassam,a) J. F. Drake, Deepak Goel, and D. P August 1999; accepted 23 November 1999 A stationary equilibrium of a liquid metal flowing past an axial field. The liquid metal flow can be maintained by a sufficiently high pressure head. The scheme
Pulsed Gradient Spin Echo Nuclear Magnetic Resonance Imaging of Diffusion in Granular Flow
Seymour, Joseph D.; Caprihan, Arvind; Altobelli, Stephen A.; Fukushima, Eiichi
2000-01-10
We derive the formalism to obtain spatial distributions of collisional correlation times for macroscopic particles undergoing granular flow from pulsed gradient spin echo nuclear magnetic resonance diffusion data. This is demonstrated with an example of axial motion in the shear flow regime of a 3D granular flow in a horizontal rotating cylinder at one rotation rate. (c) 2000 The American Physical Society.
A Comparative Study of Modular Axial Flux Podded Generators for Marine Current Turbines
Brest, Université de
A Comparative Study of Modular Axial Flux Podded Generators for Marine Current Turbines Sofiane turbines (MCTs). Due to the submarine environment, maintenance operations are very hard, very costly current turbine, axial flux permanent magnet generator, design, optimization. Nomenclature MCT = Marine
Self-Organizing Map and Axial Spatial Arrangement Topological Mapping of Alternative Designs
Self-Organizing Map and Axial Spatial Arrangement Topological Mapping of Alternative Designs and Axial Spatial Arrangement:Topological Mapping of Alternative Designs properties of the objects alternatives, make it difficult to compare alternatives, and require tedious user intervention. One
Design and optimization of a bi-axial vibration-driven electromagnetic...
Office of Scientific and Technical Information (OSTI)
Design and optimization of a bi-axial vibration-driven electromagnetic generator Citation Details In-Document Search Title: Design and optimization of a bi-axial vibration-driven...
Introducing light vector and axial vector mesons in the union of chiral and heavy quark symmetries
Kamal, A.N.; Xu, Q.P. (Theoretical Physics Institute and Department of Physics, University of Alberta, Edmonton, Alberta, T6G 2J1 (Canada))
1994-02-01
We introduce light vector and axial vector mesons as gauge particles in a (broken) local SU[sub [ital L
A Moore-Greitzer axial compressor model with spool Jan Tommy Gravdahl and Olav Egeland
Gravdahl, Jan Tommy
A Moore-Greitzer axial compressor model with spool dynamics. Jan Tommy Gravdahl and Olav Egeland applies to centrifugal compressors. It seems that the modeling and control of an axial com- pression) Table 1: Development in compressor stall/surge- control. A=Axial, C=Centrifugal, M=Modeling, C
A new estimation of the axial shielding factors for multishell cylindrical shields
Paperno, Eugene
A new estimation of the axial shielding factors for multishell cylindrical shields Eugene Paperno double and multiple-shell axial magnetic shielding is obtained as a result of numerical verification of the new algorithm, a new formula describing multishell axial magnetic shielding is suggested. © 2000
Fuel axial relocation in ballooning fuel rods. [PWR; BWR
Siefken, L.J.
1983-01-01
Fuel movement, in the longitudinal direction in ballooning fuel rods, shifts the position of heat generation and may cause an increase in cladding temperature in the ballooning region. This paper summarizes the axial fuel relocation data obtained in fuel rod tests conducted in the United States and the Federal Republic of Germany, describes a model for calculating fuel axial relocation, and gives a quantitative analysis of the impact of fuel relocation on cladding temperature. The amount of fuel relocation in 18 ballooned fuel rods was determined from neutron radiographs, niobium gamma decay counts, and photomicrographs. The fuel rods had burnups in the range of 0 to 35,000 MWd/t and cladding hoop strains varying from 0 to 72%.
Axially staged combustion system for a gas turbine engine
Bland, Robert J. (Oviedo, FL)
2009-12-15
An axially staged combustion system is provided for a gas turbine engine comprising a main body structure having a plurality of first and second injectors. First structure provides fuel to at least one of the first injectors. The fuel provided to the one first injector is adapted to mix with air and ignite to produce a flame such that the flame associated with the one first injector defines a flame front having an average length when measured from a reference surface of the main body structure. Each of the second injectors comprising a section extending from the reference surface of the main body structure through the flame front and having a length greater than the average length of the flame front. Second structure provides fuel to at least one of the second injectors. The fuel passes through the one second injector and exits the one second injector at a location axially spaced from the flame front.
Laird, Daniel L.; Johnson, Erick L.; Ochs, Margaret Ellen; Boren, Blake
2013-05-01
This report considers and prioritizes potential technical costreduction pathways for axialflow turbines designed for tidal, river, and ocean current resources. This report focuses on technical research and development costreduction pathways related to the device technology rather than environmental monitoring or permitting opportunities. Three sources of information were utilized to understand current cost drivers and develop a list of potential costreduction pathways: a literature review of technical work related to axialflow turbines, the U.S. Department of Energy Reference Model effort, and informal webinars and other targeted interactions with industry developers. Data from these various information sources were aggregated and prioritized with respect to potential impact on the lifetime levelized cost of energy. The four most promising costreduction pathways include structural design optimization; improved deployment, maintenance, and recovery; system simplicity and reliability; and array optimization.
Quantifying non-axial deformations in rat myocardium
Aghassibake, Kristina Diane
2005-02-17
Nearly forty years after the introduction of the sliding filament theory, Zahalak expanded Huxley?s cross-bridge model from a uniaxial description of length changes in the fiber direction to a three-dimensional model that accounts for non-axial active..., and is therefore a viscoelastic material. However, in the case of cyclic loading, myocardium behaves elastically when the loading and unloading phases are considered independently; hence, 16 many investigators choose to treat myocardium as a pseudoelastic...
McFarland, A.R.; Rodgers, J.C.; Ortiz, C.A.; Nelson, D.C.
1994-08-16
The present invention includes a combination of an elbow pressure drop generator and a shunt-type mass flow sensor for providing an output which gives the mass flow rate of a gas that is nearly independent of the density of the gas. For air, the output is also approximately independent of humidity. 3 figs.
S. A. Voloshin
2002-11-20
Recent experimental results on directed and elliptic flow, theoretical developments, and new techniques for anisotropic flow analysis are reviewed.
Weber, N; Priede, J; Stefani, F; Weier, T
2014-01-01
The Tayler instability is a kink-type flow instability which occurs when the electrical current through a conducting fluid exceeds a certain critical value. Originally studied in the astrophysical context, the instability was recently shown to be also a limiting factor for the upward scalability of liquid metal batteries. In this paper, we continue our efforts to simulate this instability for liquid metals within the framework of an integro-differential equation approach. The original solver is enhanced by multi-domain support with Dirichlet-Neumann partitioning for the static boundaries. Particular focus is laid on the detailed influence of the axial electrical boundary conditions on the characteristic features of the Tayler instability, and, secondly, on the occurrence of electro-vortex flows and their relevance for liquid metal batteries.
Convective cores in galactic cooling flows
A. Kritsuk; T. Plewa; E. Mueller
2001-05-02
We use hydrodynamic simulations with adaptive grid refinement to study the dependence of hot gas flows in X-ray luminous giant elliptical galaxies on the efficiency of heat supply to the gas. We consider a number of potential heating mechanisms including Type Ia supernovae and sporadic nuclear activity of a central supermassive black hole. As a starting point for this research we use an equilibrium hydrostatic recycling model (Kritsuk 1996). We show that a compact cooling inflow develops, if the heating is slightly insufficient to counterbalance radiative cooling of the hot gas in the central few kiloparsecs. An excessive heating in the centre, instead, drives a convectively unstable outflow. We model the onset of the instability and a quasi-steady convective regime in the core of the galaxy in two-dimensions assuming axial symmetry. Provided the power of net energy supply in the core is not too high, the convection remains subsonic. The convective pattern is dominated by buoyancy driven large-scale mushroom-like structures. Unlike in the case of a cooling inflow, the X-ray surface brightness of an (on average) isentropic convective core does not display a sharp maximum at the centre. A hybrid model, which combines a subsonic peripheral cooling inflow with an inner convective core, appears to be stable. We also discuss observational implications of these results.
Viscous throughflow modeling of axial compressor bladerows using a tangential blade force hypothesis
Gallimore, S.J.
1998-10-01
This paper describes the modeling of axial compressor blade rows in an axisymmetric viscous throughflow method. The basic method, which has been reported previously, includes the effects of spanwise mixing, using a turbulent diffusion model, and endwall shear within the throughflow calculation. The blades are modeled using a combination of existing two-dimensional blade performance predictions for loss and deviation away from the annulus walls and a novel approach using tangential blade forces in the endwall regions. Relatively simple assumptions about the behavior of the tangential static pressure force imposed by the blades allow the secondary deviations produced by tip clearance flows and the boundary layer flows at fixed blade ends to be calculated in the axisymmetric model. Additional losses are assigned in these regions based on the calculated deviations. The resulting method gives realistic radial distributions of loss and deviation across the whole span at both design and off-design operating conditions, providing a quick method of estimating the magnitudes of these effects in the preliminary design process. Results from the method are compared to measured data in low and high-speed compressors and multistage three-dimensional viscous CFD predictions.
Sound field near hydrothermal vents on Axial Seamount, Juan de Fuca Ridge. Technical report
Little, S.A.; Stolzenbach, K.D.; Purdy, G.M.
1990-08-10
High-quality acoustic noise measurements were obtained by two hydrophones located 3 m and 40 m from an active hydrothermal vent on Axial Seamount, Juan de Fuca Ridge, in an effort to determine the feasibility of monitoring hydrothermal vent activity through flow noise generation. Most of the measured noise field could be attributed to ambient ocean noise sources of microseisms, distant shipping, and weather, punctuated by local ships and biological sources. Long-period, low-velocity, water/rock interface waves were detected with high amplitudes which rapidly decayed with distance from the seafloor. Detection of vent signals was hampered by unexpected spatial nonstationarity due to the shadowing effects of the calders wall. No continuous vent signals were deemed significant based on a criterion of 90% probability of detection and 5% probability of false alarm. However, a small signal near 40 Hz, with a power level of 0.0001 Pa sq/Hz was noticed on two records taken within 3 m of the Inferno black smoker. The frequency of this signal is consistent with predictions, and the power level suggests the occurrence of jet noise amplification due to convected density inhomogeneities. Keywords: Seamounts; Flow noise; Underwater acoustics; Acoustic measurement; Geothermy/noise; Ocean ridges; Underwater sound signals; Reprints; North Pacific Ocean. (EDC).
Xia, Minggang, E-mail: xiamg@mail.xjtu.edu.cn [Laboratory of Nanostructure and Physics Properties, and MOE Key Laboratory for Non-equilibrium Synthesis and Modulation of Condensed Matter, School of Science, Xi'an Jiaotong University, 710049 (China); Department of Optical Information Science and Technology, School of Science, Xi'an Jiaotong University, 710049 (China); Han, Jinyun; Cheng, Zhaofang; Liang, Chunping; Zhang, Shengli [Laboratory of Nanostructure and Physics Properties, and MOE Key Laboratory for Non-equilibrium Synthesis and Modulation of Condensed Matter, School of Science, Xi'an Jiaotong University, 710049 (China); Department of Applied Physics, School of Science, Xi'an Jiaotong University, Shaanxi 710049 (China)
2014-09-08
The characterization of junctions in nanowires by high-resolution transmission electron microscopy with spherical aberration correction is tricky and tedious. Many disadvantages also exist, including rigorous sample preparation and structural damage inflicted by high-energy electrons. In this work, we present a simple, low-cost, and non-destructive Raman spectroscopy method of characterizing anomalous junctions in nanowires with axially degraded components. The Raman spectra of Si{sub x}Ge{sub 1?x} nanowires with axially degraded components are studied in detail using a confocal micro-Raman spectrometer. Three Raman peaks (?{sub Si–Si}?=?490?cm{sup ?1}, ?{sub Si–Ge}?=?400?cm{sup ?1}, and ?{sub Ge–Ge}?=?284?cm{sup ?1}) up-shift with increased Si content. This up-shift originates in the bond compression induced by a confined effect on the radial direction of nanowire. The anomalous junctions in Si{sub x}Ge{sub 1?x} nanowires with axially degraded components are then observed by Raman spectroscopy and verified by transmission electron microscopy energy-dispersive X-ray spectroscopy. The anomalous junctions of Si{sub x}Ge{sub 1?x} nanowires with axially degraded components are due to the vortex flow of inlet SiH{sub 4} and GeH{sub 4} gas in their synthesis. The anomalous junctions can be used as raw materials for fabricating devices with special functions.
Crushing modes of aluminium tubes under axial compression
Florent Henri Marc Rémy Pled; Wenyi Yan; Cui'E Wen
2014-08-21
A numerical study of the crushing of circular aluminium tubes with and without aluminium foam fillers has been carried out to investigate their buckling behaviours under axial compression. A crushing mode classification chart has been established for empty tubes. The influence of boundary conditions on crushing mode has also been investigated. The effect of foam filler on the crushing mode of tubes filled with foam was then examined. The predicted results would assist the design of crashworthy tube components with the preferred crushing mode with the maximum energy absorption.
Axial clad strain behavior of sphere-pac fuel pins
Thomas, James Kelly
1986-01-01
d (Head of Depar trnent) May 1986 ABSTRACT Axial Clad Str ain Behavior of Spher e-Pac Fuel Pins (May 1986) James Kelly Thomas, B. S. , Texas AAM Univer sity Chairman of Advisor y Committee: Dn. K. L. Peddicor d Advanced nuclear f'uels ar e... being investigated to extend the lifetime and oper ating f'lexibility of fuel pins. An alter native to pellet f'uel that might satisfy these goals is spher e-pac nuclear fuel. Spher e-pac ir radiations have been per formed in the U. S. , Switzer land...
Spatiotemporal focusing does not always improve axial intensity localization
Cheng, Ya; Wang, Zhaohui; Li, Guihua; Zeng, Bin; He, Fei; Chu, Wei; Yao, Jinping; Qiao, Lingling
2015-01-01
We report on an experimental comparison on critical intensities of nonlinear self-focusing in air with conventional focusing and spatiotemporal focusing schemes. Our results show that the conventional focusing with the focal lens completely filled with the incident beam allows for the strongest axial intensity confinement against the self-focusing effect. This is because that in the high-numerical-aperture condition, the focal spot will have a compact size which results in a high focal intensity. Meanwhile, the Rayleigh length of the focused beam will be substantially shortened which efficiently postpones the onset of self-focusing.
Paperno, Eugene
--Amorphous Metglas material, axial (longitudinal) shielding equation, demagnetizing factor, cylindrical shields
SIMULATION OF TIP LEAKAGE FLOW AROUND PARTIAL SQUEALER RIMS IN AXIAL TURBINES
Camci, Cengiz
is to protect the blade tip and cooling system from smear damage. This is a way of obtaining tighter design visualizations in extremely small geometrical features encountered near blade tip sections. After describing the control of squealer rims are described in various planes parallel to the blade tip platform on which
Development of a transonic front stage of an axial flow compressor for industrial gas turbines
Katoh, Y.; Ishii, H.; Tsuda, Y.; Yanagida, M. . Mechanical Engineering Research Lab.); Kashiwabara, Y. . Dept. of Mechanical Systems Engineering)
1994-10-01
This paper describes the aerodynamic blade design of a highly loaded three-stage compressor, which is a model compressor for the front stage of an industrial gas turbine. Test results are presented that confirm design performance. Some surge and rotating stall measurement results are also discussed. The first stator blade in this test compressor operates in the high subsonic range at the inlet. To reduce the pressure loss due to blade surface shock waves, a shock-free airfoil is designed to replace the first stator blade in an NACA-65 airfoil in a three-stage compressor. Comparison of the performance of both blades shows that the shock-free airfoil blade reduces pressure loss. This paper also presents some experimental results for MCA (multicircular arc) airfoils, which are used for first rotor blades.
Design, build and test of an axial flow hydrokinetic turbine with fatigue analysis
Ketcham, Jerod W
2010-01-01
OpenProp is an open source propeller and turbine design and analysis code that has been in development since 2007 by MIT graduate students under the supervision of Professor Richard Kimball. In order to test the performance ...
Effects of Large Energetic Vortices on Axial-Flow Hydrokinetic Turbines
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AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantityBonneville Power Administration would like submitKansas Nuclear Profile 2010MesoscopyStaff Â»VehicleEffective
Competition between modes with different axial structures in gyrotrons
Khutoryan, Eduard M.; Nusinovich, Gregory S.; Sinitsyn, Oleksandr V.
2014-09-15
This study was motivated by some experiments in which it was found that during the voltage rise, instead of expected excitation of a high-frequency parasitic mode, the excitation of a lower-frequency parasitic mode takes place in a certain range of voltages. For explaining this fact, the dependence of start currents of possible competing modes on the beam voltage was carried out in the cold-cavity approximation and by using the self-consistent approach. It was found that in the case of cavities, which consist of the combination of a section of constant radius waveguide and a slightly uptapered waveguide, these two approaches yield completely different results. Thus, experimentally observed excitation of the low-frequency parasitic mode can be explained by the self-consistent modification of the axial profile of the excited field, which has strong influence on the diffractive quality factor of competing modes. This modification is especially pronounced in the case of excitation of modes with many axial variations which can be excited in the region of beam interaction with the backward-wave component of such modes.
Electrostatic waves in carbon nanotubes with an axial magnetic field
Abdikian, Alireza; Bagheri, Mehran
2013-10-15
Based on a linearized hydrodynamic model and within the quasi-static approximation, the dispersion relation of electrostatic waves propagating through single-walled carbon nanotubes subject to an axial magnetic field is theoretically explored. In the classical limit, we obtain two main possible waves which in turn are divided into two branches, a low-frequency acoustical and a high-frequency optical plasmon branch. In the quantum case, we have found that the dispersion relation is substantially modified when the electron wavelength becomes large enough compared to the propagation wavelength of the electrostatic waves in the quantum plasma. We also show that the axial magnetic field manifest itself on the perturbed electron density through the quantum term and gives rise to the propagation of the electrostatic waves within the quantum plasma. As a result, the effect of the magnetic field is pronounced in the plasma dispersion relations in such a way that their curves approach to zero when the magnetic field is weak; and for the strong magnetic field, they asymptotically meet the constant lines.
Stability and angular-momentum transport of fluid flows between corotating cylinders
Avila, Marc
2012-01-01
Turbulent transport of angular momentum is a necessary process to explain accretion in astrophysical disks. Although the hydrodynamic stability of disk-like flows has been tested in experiments, results are contradictory and suggest either laminar or turbulent flow. Direct numerical simulations reported here show that currently investigated laboratory flows are hydrodynamically unstable and become turbulent at low Reynolds numbers. The underlying instabilities stem from the axial boundary conditions, affect the flow globally and enhance angular-momentum transport.
Yu. N. Bratkov
2010-04-03
Flow analysis of big basins is given. Internal structure of flows is considered. Correlations between flows are calculated. For example, Mare Orientale is a moving basin. Orientale and Imbrium continental basins are introduced and are considered. Olbers ray crater is a result of precise interaction of the two basins. Flows of the Tycho type are studied. Two Antarctidae, an Indian Ocean, and an America are demonstrated.
Street-based Topological Representations and Analyses for Predicting Traffic Flow in GIS
Jiang, Bin
2007-01-01
It is well received in the space syntax community that traffic flow is significantly correlated to a morphological property of streets, which are represented by axial lines, forming a so called axial map. The correlation co-efficient (R square value) approaches 0.8 and even a higher value according to the space syntax literature. In this paper, we study the same issue using the Hong Kong street network and the Hong Kong Annual Average Daily Traffic (AADT) datasets, and find surprisingly that street-based topological representations (or street-street topologies) tend to be better representations than the axial map. In other words, vehicle flow is correlated to a morphological property of streets better than that of axial lines. Based on the finding, we suggest the street-based topological representations as an alternative GIS representation, and the topological analyses as a new analytical means for geographic knowledge discovery.
Flow visualization and leakage measurements of labyrinth seals
Johnson, James Wayne
1996-01-01
, seals are tested over a range of Reynolds numbers, step heights, and axial offset positions (where applicable) for a fixed annular clearance. A permanent flow visualization record for each experiment is kept and analyzed in both real-time and slow motion...
A new endwall model for axial compressor throughflow calculations
Dunham, J.
1995-10-01
It is well recognized that the endwall regions of a compressor--in which the annulus wall flow interacts with the mainstream flow--have a major influence on its efficiency and surge margin. Despite many attempts over the years to predict the very complex flow patterns in the endwall regions, current compressor design methods still rely largely on empirical estimates of the aerodynamic losses and flow angle deviations in these regions. This paper describes a new phenomenological model of the key endwall flow phenomena treated in a circumferentially averaged way. It starts from Hirsch and de Ruyck`s annulus wall boundary layer approach, but makes some important changes. The secondary vorticities arising from passage secondary flows and from tip clearance flows are calculated. Then the radial interchanges of momentum, energy, and entropy arising from both diffusion and convection are estimated. The model is incorporated into a streamline curvature program. The empirical blade force defect terms in the boundary layers are selected from cascade data. The effectiveness of the method is illustrated by comparing the predictions with experimental results on both low-speed and high-speed multistage compressors. It is found that the radial variation of flow parameters is quite well predicted, and so is the overall performance, except when significant endwall stall occurs.
Three-Dimensional Tidal Flow in an Elongated, Rotating Basin CLINTON D. WINANT
Winant, Clinton D.
Three-Dimensional Tidal Flow in an Elongated, Rotating Basin CLINTON D. WINANT Integrative-dimensional tidal circulation in an elongated basin of arbitrary depth is described with a linear, constant parcels tend to corkscrew into and out of the basin in a tidal period. The axial flow is only weakly
Numerical modeling of heat transfer and fluid flow in rotor-stator cavities with throughflow
Boyer, Edmond
Numerical modeling of heat transfer and fluid flow in rotor-stator cavities with throughflow S the dynamical effects from the heat transfer process. The fluid flow in an enclosed disk system with axial with heat transfer along the stator, which corresponds to the experiment of Djaoui et al. [2]. Our results
Thermoacoustic mixture separation with an axial temperature gradient
Geller, Drew W; Swift, Gregory A
2008-01-01
The theory of thermoacoustic mixture separation is extended to include the effect of a nonzero axial temperature gradient. The analysis yields a new term in the second-order mole flux that is proportional to the temperature gradient and to the square of the volumetric velocity and is independent of the phasing of the wave. Because of this new term, thermoacoustic separation stops at a critical temperature gradient and changes direction above that gradient. For a traveling wave, this gradient is somewhat higher than that predicted by a simple four-step model. An experiment tests the theory for temperature gradients from 0 to 416 K/m in 50-50 He-Ar mixtures.
Axially symmetric dissipative fluids in the quasi--static approximation
Herrera, L; Ospino, J; Carot, J
2015-01-01
Using a framework based on the $1+3$ formalism we carry out a study on axially and reflection symmetric dissipative fluids, in the quasi--static regime. We first derive a set of invariantly defined "velocities", which allow for an inambiguous definition of the quasi--static approximation. Next we rewrite all the relevant equations in this aproximation and extract all the possible, physically relevant, consequences ensuing the adoption of such an approximation. In particular we show how the vorticity, the shear and the dissipative flux, may lead to situations where different kind of "velocities" change of sign within the fluid distribution with respect to theirs sign on the boundary surface. It is shown that states of gravitational radiation are not {\\it a priori} incompatible with the quasistatic--regime. However, any such state must last for an infinite period of time, thereby diminishing its physical relevance.
Teleparallel Energy-Momentum Distribution of Static Axially Symmetric Spacetimes
M. Sharif; M. Jamil Amir
2007-04-17
This paper is devoted to discuss the energy-momentum for static axially symmetric spacetimes in the framework of teleparallel theory of gravity. For this purpose, we use the teleparallel versions of Einstein, Landau-Lifshitz, Bergmann and M$\\ddot{o}$ller prescriptions. A comparison of the results shows that the energy density is different but the momentum turns out to be constant in each prescription. This is exactly similar to the results available in literature using the framework of General Relativity. It is mentioned here that M$\\ddot{o}$ller energy-momentum distribution is independent of the coupling constant $\\lambda$. Finally, we calculate energy-momentum distribution for the Curzon metric, a special case of the above mentioned spacetime.
Hoffman, E.L.; Ammerman, D.J.
1993-08-01
A series of tests investigating dynamic pulse buckling of a cylindrical shell under axial impact is compared to several finite element simulations of the event. The purpose of the study is to compare the performance of the various analysis codes and element types with respect to a problem which is applicable to radioactive material transport packages, and ultimately to develop a benchmark problem to qualify finite element analysis codes for the transport package design industry.
Axial couplings and strong decay widths of heavy hadrons
William Detmold, C.-J. David Lin, Stefan Meinel
2012-04-01
We calculate the axial couplings of mesons and baryons containing a heavy quark in the static limit using lattice QCD. These couplings determine the leading interactions in heavy hadron chiral perturbation theory and are central quantities in heavy quark physics, as they control strong decay widths and the light-quark mass dependence of heavy hadron observables. Our analysis makes use of lattice data at six different pion masses, 227 MeV < m{sub {pi}} < 352 MeV, two lattice spacings, a = 0.085, 0.112 fm, and a volume of (2.7 fm){sup 3}. Our results for the axial couplings are g{sub 1} = 0.449(51), g{sub 2} = 0.84(20), and g{sub 3} = 0.71(13), where g{sub 1} governs the interaction between heavy-light mesons and pions and g{sub 2,3} are similar couplings between heavy-light baryons and pions. Using our lattice result for g{sub 3}, and constraining 1/m{sub Q} corrections in the strong decay widths with experimental data for {Sigma}{sub c}{sup (*)} decays, we obtain {Gamma}[{Sigma}{sub b}{sup (*)} {yields} {Lambda}{sub b} {pi}{sup {+-}}] = 4.2(1.0), 4.8(1.1), 7.3(1.6), 7.8(1.8) MeV for the {Sigma}{sub b}{sup +}, {Sigma}{sub b}{sup -}, {Sigma}{sub b}{sup *+}, {Sigma}{sub b}{sup *-} initial states, respectively. We also derive upper bounds on the widths of the {Xi}{sub b}{sup prime(*)} baryons.
McKay, M.D.; Sweeney, C.E.; Spangler, B.S. Jr.
1993-11-30
A flow meter and temperature measuring device are described comprising a tube with a body centered therein for restricting flow and a sleeve at the upper end of the tube to carry several channels formed longitudinally in the sleeve to the appropriate axial location where they penetrate the tube to allow pressure measurements and temperature measurements with thermocouples. The high pressure measurement is made using a channel penetrating the tube away from the body and the low pressure measurement is made at a location at the widest part of the body. An end plug seals the end of the device and holes at its upper end allow fluid to pass from the interior of the tube into a plenum. The channels are made by cutting grooves in the sleeve, the grooves widened at the surface of the sleeve and then a strip of sleeve material is welded to the grooves closing the channels. Preferably the sleeve is packed with powdered graphite before cutting the grooves and welding the strips. 7 figures.
McKay, Mark D. (1426 Socastee Dr., North Augusta, SC 29841); Sweeney, Chad E. (3600 Westhampton Dr., Martinez, GA 30907-3036); Spangler, Jr., B. Samuel (2715 Margate Dr., Augusta, GA 30909)
1993-01-01
A flow meter and temperature measuring device comprising a tube with a body centered therein for restricting flow and a sleeve at the upper end of the tube to carry several channels formed longitudinally in the sleeve to the appropriate axial location where they penetrate the tube to allow pressure measurements and temperature measurements with thermocouples. The high pressure measurement is made using a channel penetrating the tube away from the body and the low pressure measurement is made at a location at the widest part of the body. An end plug seals the end of the device and holes at its upper end allow fluid to pass from the interior of the tube into a plenum. The channels are made by cutting grooves in the sleeve, the grooves widened at the surface of the sleeve and then a strip of sleeve material is welded to the grooves closing the channels. Preferably the sleeve is packed with powdered graphite before cutting the grooves and welding the strips.
Zha, Gecheng
Investigation of Non-synchronous Vibration Mechanism for a High Speed Axial Compressor Using compressor. DDES is a hybrid model for turbulence simulation, which uses RANS model within the wall boundary a torsion moment causing NSV. 1 Introduction Non-synchronous vibration of axial fan/compressor is a non
Design Technical Briefs Valve-Plate Design for an Axial Piston
Manring, Noah D.
standby when they are used to hold pressure at low displacements. Noisy pumps also tend to wear outJournal of Mechanical Design Technical Briefs Valve-Plate Design for an Axial Piston Pump Operating advantages of using various valve-plate slot geometries within an axial piston pump. In particular, three
Constable, Steve
Seamount, Juan de Fuca Ridge S. C. CONSTABLE', G. S. HEINSON2, G. ANDERSON', and A. WHITE2 'Scripps be present only beneath Axial Seamount, surrounded by a resistive lithosphere of 500-50,000 u1m. The tectonic in fractures or pipes. 1. Introduction AxialSeamountlieson the Juan deFucaRidge,about 500km westof
Tinkering with the axial skeleton: vertebral number variation in ecologically divergent threespine
Aguirre, Windsor E.
for publication 25 March 2014 Understanding how the vertebral column is impacted as populations adapt to differentTinkering with the axial skeleton: vertebral number variation in ecologically divergent threespine in the axial skeleton. We examined variation of vertebral number and body shape in morphologically
1 Mayne & Schneider EVALUATING AXIAL DRILLED SHAFT RESPONSE BY SEISMIC CONE
Mayne, Paul W.
1 Mayne & Schneider EVALUATING AXIAL DRILLED SHAFT RESPONSE BY SEISMIC CONE Paul W. Mayne1 , M using the results of seismic piezocone penetration tests (SCPTU) to provide continuous profiles of small to discuss the use of seismic piezocone testing for the evaluation of both axial capacity (obtained from
Dispersion relation and growth rate in a Cherenkov free electron laser: Finite axial magnetic field
Kheiri, Golshad; Esmaeilzadeh, Mahdi
2013-12-15
A theoretical analysis is presented for dispersion relation and growth rate in a Cherenkov free electron laser with finite axial magnetic field. It is shown that the growth rate and the resonance frequency of Cherenkov free electron laser increase with increasing axial magnetic field for low axial magnetic fields, while for high axial magnetic fields, they go to a saturation value. The growth rate and resonance frequency saturation values are exactly the same as those for infinite axial magnetic field approximation. The effects of electron beam self-fields on growth rate are investigated, and it is shown that the growth rate decreases in the presence of self-fields. It is found that there is an optimum value for electron beam density and Lorentz relativistic factor at which the maximum growth rate can take place. Also, the effects of velocity spread of electron beam are studied and it is found that the growth rate decreases due to the electron velocity spread.
Pressure balanced drag turbine mass flow meter
Dacus, Michael W. (Gilbert, AR); Cole, Jack H. (Fayetteville, AR)
1982-01-01
The density of the fluid flowing through a tubular member may be measured by a device comprising a rotor assembly suspended within the tubular member, a fluid bearing medium for the rotor assembly shaft, independent fluid flow lines to each bearing chamber, and a scheme for detection of any difference between the upstream and downstream bearing fluid pressures. The rotor assembly reacts to fluid flow both by rotation and axial displacement; therefore concurrent measurements may be made of the velocity of blade rotation and also bearing pressure changes, where the pressure changes may be equated to the fluid momentum flux imparted to the rotor blades. From these parameters the flow velocity and density of the fluid may be deduced.
Pressure balanced drag turbine mass flow meter
Dacus, M.W.; Cole, J.H.
1980-04-23
The density of the fluid flowing through a tubular member may be measured by a device comprising a rotor assembly suspended within the tubular member, a fluid bearing medium for the rotor assembly shaft, independent fluid flow lines to each bearing chamber, and a scheme for detection of any difference between the upstream and downstream bearing fluid pressures. The rotor assembly reacts to fluid flow both by rotation and axial displacement; therefore concurrent measurements may be made of the velocity of blade rotation and also bearing pressure changes, where the pressure changes may be equated to the fluid momentum flux imparted to the rotor blades. From these parameters the flow velocity and density of the fluid may be deduced.
The cool component and the dichotomy, lateral expansion, and axial rotation of solar X-ray jets
Moore, Ronald L.; Sterling, Alphonse C.; Falconer, David A.; Robe, Dominic
2013-06-01
We present results from a study of 54 polar X-ray jets that were observed in coronal X-ray movies from the X-ray Telescope on Hinode and had simultaneous coverage in movies of the cooler transition region (T ? 10{sup 5} K) taken in the He II 304 Å band of the Atmospheric Imaging Assembly (AIA) on Solar Dynamics Observatory. These dual observations verify the standard-jet/blowout-jet dichotomy of polar X-ray jets previously found primarily from XRT movies alone. In accord with models of blowout jets and standard jets, the AIA 304 Å movies show a cool (T ? 10{sup 5} K) component in nearly all blowout X-ray jets and in a small minority of standard X-ray jets, obvious lateral expansion in blowout X-ray jets but none in standard X-ray jets, and obvious axial rotation in both blowout X-ray jets and standard X-ray jets. In our sample, the number of turns of axial rotation in the cool-component standard X-ray jets is typical of that in the blowout X-ray jets, suggesting that the closed bipolar magnetic field in the jet base has substantial twist not only in all blowout X-ray jets but also in many standard X-ray jets. We point out that our results for the dichotomy, lateral expansion, and axial rotation of X-ray jets add credence to published speculation that type-II spicules are miniature analogs of X-ray jets, are generated by granule-size emerging bipoles, and thereby carry enough energy to power the corona and solar wind.
Reliability of steam generator tubes with axial cracks
Cizelj, L.; Mavko, B. [Jozef Stefan Inst., Ljubljana (Slovenia). Reactor Engineering Div.; Vencelj, P. [Univ. of Ljubljana (Slovenia). Faculty of Mathematics and Physics
1996-11-01
An approach for estimating the failure probability of tubes containing through-wall axial cracks has already been proposed by the authors. It is based on probabilistic fracture mechanics and accounts for scatter in tube geometry and material properties, scatter in residual and operational stresses responsible for crack propagation, and characteristics of nondestructive examination and plugging procedures (e.g., detection probability, sizing accuracy, human errors). Results of preliminary tests demonstrated wide applicability of this approach and triggered some improvements. The additions to the model are extensively discussed in this paper. Capabilities are demonstrated by results of analysis of steam generator no. 1 in Slovenian nuclear power plant located in Krsko after the 1992 inspection and plugging campaign. First, the number of cracked tubes and the crack length distribution were estimated using data obtained by the 100% motorized pancake coil inspection. The inspection and plugging activities were simulated in the second step to estimate the efficiency of maintenance in terms of single and multiple-tube rupture probabilities. They were calculated as a function of maximum allowable crack length. The importance of human errors and some limitations of present nondestructive examination techniques were identified. The traditional wall thickness and crack-length-based plugging criteria are compared. The crack-length-based criterion is shown to be more efficient and more safe, especially because of strong suppression effect on probability of multiple-tube rupture. The results are considered to be important for safety and maintenance of existing plants and for further research.
Negative particle planar and axial channeling and channeling collimation
Carrigan, Richard A., Jr.; /Fermilab
2009-12-01
While information exists on high energy negative particle channeling there has been little study of the challenges of negative particle bending and channeling collimation. Partly this is because negative dechanneling lengths are relatively much shorter. Electrons are not particularly useful for investigating negative particle channeling effects because their material interactions are dominated by channeling radiation. Another important factor is that the current central challenge in channeling collimation is the proton-proton Large Hadron Collider (LHC) where both beams are positive. On the other hand in the future the collimation question might reemerge for electon-positron or muon colliders. Dechanneling lengths increase at higher energies so that part of the negative particle experimental challenge diminishes. In the article different approaches to determining negative dechanneling lengths are reviewed. The more complicated case for axial channeling is also discussed. Muon channeling as a tool to investigate dechanneling is also discussed. While it is now possible to study muon channeling it will probably not illuminate the study of negative dechanneling.
Auluck, S. K. H.
2014-10-15
Direct measurement of axial magnetic field in the PF-1000 dense plasma focus (DPF), and its reported correlation with neutron emission, call for a fresh look at previous reports of existence of axial magnetic field component in the DPF from other laboratories, and associated data suggesting toroidal directionality of fast ions participating in fusion reactions, with a view to understand the underlying physics. In this context, recent work dealing with application of the hyperbolic conservation law formalism to the DPF is extended in this paper to a curvilinear coordinate system, which reflects the shape of the DPF current sheath. Locally unidirectional shock propagation in this coordinate system enables construction of a system of 7 one-dimensional hyperbolic conservation law equations with geometric source terms, taking into account all the components of magnetic field and flow velocity. Rankine-Hugoniot jump conditions for this system lead to expressions for the axial magnetic field and three components of fluid velocity having high ion kinetic energy.
Axial current generation by P-odd domains in QCD matter
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
Iatrakis, Ioannis; Yin, Yi; Lin, Shu
2015-06-23
The dynamics of topological domains which break parity (P) and charge-parity (CP) symmetry of QCD are studied. We derive in a general setting that those local domains will generate an axial current and quantify the strength of the induced axial current. Thus, our findings are verified in a top-down holographic model. The relation between the real time dynamics of those local domains and the chiral magnetic field is also elucidated. We finally argue that such an induced axial current would be phenomenologically important in a heavy-ion collisions experiment.
Singlet axial-vector coupling constant of the nucleon in QCD without instantons
Janardan P. Singh
2015-07-19
We have analyzed axial-vector current-current correlation functions between one-nucleon states to calculate the singlet axial-vector coupling constant of the nucleon. The octet-octet and the octet-singlet current correlators, investigated in this work, do not require any use of instanton effects. The QCD and hadronic parameters used for the evaluation of correlators have been varied by (10 - 20)%. The value of the singlet axial-vector coupling constant of the nucleon obtained from this analysis is consistent with its current determination from experiments and QCD theory.
The Flow of Newtonian Fluids in Axisymmetric Corrugated Tubes
Taha Sochi
2010-06-08
This article deals with the flow of Newtonian fluids through axially-symmetric corrugated tubes. An analytical method to derive the relation between volumetric flow rate and pressure drop in laminar flow regimes is presented and applied to a number of simple tube geometries of converging-diverging nature. The method is general in terms of fluid and tube shape within the previous restrictions. Moreover, it can be used as a basis for numerical integration where analytical relations cannot be obtained due to mathematical difficulties.
The Flow of Newtonian Fluids in Axisymmetric Corrugated Tubes
Sochi, Taha
2010-01-01
This article deals with the flow of Newtonian fluids through axially-symmetric corrugated tubes. An analytical method to derive the relation between volumetric flow rate and pressure drop in laminar flow regimes is presented and applied to a number of simple tube geometries of converging-diverging nature. The method is general in terms of fluid and tube shape within the previous restrictions. Moreover, it can be used as a basis for numerical integration where analytical relations cannot be obtained due to mathematical difficulties.
Effects of nonaxisymmetric tip clearance on axial compressor performance and stability
Graf, M.B.; Wong, T.S.; Greitzer, E.M.; Marble, F.E.; Tan, C.S.; Shin, H.W.; Wisler, D.C.
1998-10-01
The effects of circumferentially nonuniform tip clearance on axial compressor performance and stability have been investigated experimentally and analytically. A theoretical model for compressor behavior with nonaxisymmetric tip clearance has been developed and used to design a series of first-of-a-kind experiments on a four-stage, low-speed compressor. The experiments and computational results together show clearly the central physical features and controlling parameters of compressor response to nonaxisymmetric tip clearance. It was found that the loss in stall margin was more severe than that estimated based on average clearance. The stall point was, in fact, closer to that obtained with uniform clearance at the maximum clearance level. The circumferential length scale of the tip clearance (and accompanying flow asymmetry) was an important factor in determining the stall margin reduction. For the same average clearance, the loss in peak pressure rise was 50 percent higher for an asymmetry with fundamental wavelength equal to the compressor circumference than with wavelength equal to one-half the circumference. The clearance asymmetry had much less of an effect on peak efficiency; the measured maximum efficiency decrease obtained was less than 0.4 percent compared to the 8 percent decrease in peak pressure rise due to the asymmetric clearance. The efficiency penalty due to nonaxisymmetric tip clearance was thus close to that obtained with a uniform clearance at the circumferentially averaged level. The theoretical model accurately captured the decreases in both steady-state pressure rise and stable operating range which are associated with clearance asymmetry.
Morozov, Victor (Manassas, VA)
2011-01-18
A flow chamber having a vacuum chamber and a specimen chamber. The specimen chamber may have an opening through which a fluid may be introduced and an opening through which the fluid may exit. The vacuum chamber may have an opening through which contents of the vacuum chamber may be evacuated. A portion of the flow chamber may be flexible, and a vacuum may be used to hold the components of the flow chamber together.
The effect of nonuniform axial heat flux distribution on the critical heat flux
Todreas, Neil E.
1965-01-01
A systematic experimental and analytic investigation of the effect of nonuniform axial heat flux distribution on critical heat rilux was performed with water in the quality condition. Utilizing a model which ascribes the ...
REVIEW OF SCIENTIFIC INSTRUMENTS 83, 103106 (2012) Practical axial optical trapping
Regan, Lynne
2012-01-01
REVIEW OF SCIENTIFIC INSTRUMENTS 83, 103106 (2012) Practical axial optical trapping A. H. Mack,1- fer a number of practical advantages: first, a range of meth- ods is available to tether large numbers
Designing for forces : an early-stage design program for axial-force structures
Jordan, Alexander D. W. (Alexander David Weigert)
2011-01-01
Structures that carry most of their load through the axial forces of tension or compression are more materially efficient than standard structures. However, they are not as straightforward to design since the forces in the ...
An improved blade passage model for estimating off-design axial compressor performance
Brand, Maximilian Lewis
2013-01-01
Accurate estimates of multistage axial compressor performance at off-design operating conditions are essential to the determination of key performance metrics of aircraft gas turbine engines, such as fuel burn, thrust ...
McElmurry, Blake Anthony
2009-05-15
The development of a co-axially configured submillimeter spectrometer is reported. The spectrometer has been constructed to observe molecular complexes that exhibit non-covalent interactions with energies much less than ...
Cladding axial elongation models for FRAP-T6. [PWR; BWR
Shah, V.N.; Carlson, E.R.; Berna, G.A.
1983-01-01
This paper presents a description of the cladding axial elongation models developed at the Idaho National Engineering Laboratory (INEL) for use by the FRAP-T6 computer code in analyzing the response of fuel rods during reactor transients in light water reactors (LWR). The FRAP-T6 code contains models (FRACAS-II subcode) that analyze the structural response of a fuel rod including pellet-cladding-mechanical-interaction (PCMI). Recently, four models were incorporated into FRACAS-II to calculate cladding axial deformation: (a) axial PCMI, (b) trapped fuel stack, (c) fuel relocation, and (d) effective fuel thermal expansion. Comparisons of cladding axial elongation measurements from two experiments with the corresponding FRAP-T6 calculations are presented.
Experimental demonstration of polarization-assisted transverse and axial optical superresolution
Teich, Malvin C.
, coaxial Gaussian beams with axially offset foci F1 and F2 are superposed. Since the Gouy phase for each of Electrical and Computer Engineering, Quantum Imaging Laboratory, Boston University, 8 Saint Marys Street
High-Efficiency Deflection of High-Energy Protons through Axial...
Office of Scientific and Technical Information (OSTI)
High-Efficiency Deflection of High-Energy Protons through Axial Channeling in a Bent Crystal Citation Details In-Document Search Title: High-Efficiency Deflection of High-Energy...
Time history analysis of axial forces (Pass Through Forces) at joints in a braced frame
Paschini, Vincent
2012-01-01
As buildings keep getting taller, traditional braced lateral systems take more loads. This generates a phenomenon at every joint of a frame called "Pass Through Force". Pass through forces come from the transfer of axial ...
Tatsuya Higuchi; Akimaro Kawahara; Michio Sadatomi; Hiroyuki Kudo [Kumamoto University, 39-1, Kurokami 2-chome, Kumamoto 860-8555 (Japan)
2006-07-01
Single- and two-phase diversion cross-flows arising from the pressure difference between tight lattice subchannels are our concern in this study. In order to obtain a correlation of the diversion cross-flow, we conducted adiabatic experiments using a vertical multiple-channel with two subchannels simplifying the triangle tight lattice rod bundle for air-water flows at room temperature and atmospheric pressure. In the experiments, data were obtained on the axial variations in the pressure difference between the subchannels, the ratio of flow rate in one subchannel to the whole channel, the void fraction in each subchannel for slug-churn and annular flows in two-phase flow case. These data were analyzed by use of a lateral momentum equation based on a two-fluid model to determine both the cross-flow resistance coefficient between liquid phase and channel wall and the gas-liquid interfacial friction coefficient. The resulting coefficients have been correlated in a way similar to that developed for square lattice subchannel case by Kano et al. (2002); the cross-flow resistance coefficient data can be well correlated with a ratio of the lateral velocity due to the cross-flow to the axial one irrespective of single- and two-phase flows; the interfacial friction coefficient data were well correlated with a Reynolds number, which is based on the relative velocity between gas and liquid cross-flows as the characteristic velocity. (authors)
Yu. N. Bratkov
2008-11-19
In this paper geology and planetology are considered using new conceptual basis of high-speed flow dynamics. Recent photo technics allow to see all details of a flow, 'cause the flow is static during very short time interval. On the other hand, maps and images of many planets are accessible. Identity of geological flows and high-speed gas dynamics is demonstrated. There is another time scale, and no more. All results, as far as the concept, are new and belong to the author. No formulae, pictures only.
Liles, D.R.
1982-01-01
Internal boundaries in multiphase flow greatly complicate fluid-dynamic and heat-transfer descriptions. Different flow regimes or topological configurations can have radically dissimilar interfacial and wall mass, momentum, and energy exchanges. To model the flow dynamics properly requires estimates of these rates. In this paper the common flow regimes for gas-liquid systems are defined and the techniques used to estimate the extent of a particular regime are described. Also, the current computer-code procedures are delineated and introduce a potentially better method is introduced.
Electron Diamagnetic Effect on Axial Force in an Expanding Plasma: Experiments and Theory
Takahashi, Kazunori [Space Plasma, Power and Propulsion Laboratory, Research School of Physics and Engineering, Australian National University, Canberra ACT 0200 (Australia); Department of Electrical Engineering and Computer Science, Iwate University, Morioka 020-8551 (Japan); Lafleur, Trevor; Charles, Christine; Alexander, Peter; Boswell, Rod W. [Space Plasma, Power and Propulsion Laboratory, Research School of Physics and Engineering, Australian National University, Canberra ACT 0200 (Australia)
2011-12-02
The axial force imparted from a magnetically expanding current-free plasma is directly measured for three different experimental configurations and compared with a two-dimensional fluid theory. The force component solely resulting from the expanding field is directly measured and identified as an axial force produced by the azimuthal current due to an electron diamagnetic drift and the radial component of the magnetic field. The experimentally measured forces are well described by the theory.
BEC-BCS crossover driven by the axial anomaly in the NJL model
Abuki, Hiroaki; Hatsuda, Tetsuo; Yamamoto, Naoki
2010-01-01
We study the QCD phase structure in the three-flavor Nambu--Jona-Lasinio model, incorporating the chiral-diquark interplay due to the axial anomaly. We demonstrate that for a certain range of model parameters, the low temperature critical point predicted by a Ginzburg-Landau analysis appears in the phase diagram. In addition, we show that the axial anomaly presents a new scenario for a possible BEC-BCS crossover in the color-flavor locked phase of QCD.
Relativistic Hartree-Fock-Bogoliubov Theory With Density Dependent Meson Couplings in Axial Symmetry
Ebran, J.-P.; Khan, E.; Arteaga, D. Pena; Grasso, M.; Vretenar, D.
2009-08-26
Most nuclei on the nuclear chart are deformed, and the development of new RIB facilities allows the study of exotic nuclei near the drip lines where a successful theoretical description requires both realistic pairing and deformation approaches. Relativistic Hartree-Fock-Bogoliubov model taking into account axial deformation and pairing correlations is introduced. Preliminary illustrative results with density dependent meson-nucleon couplings in axial symmetry will be discussed.
Weak axial nuclear heavy meson exchange currents and interactions of solar neutrinos with deuterons
B. Mosconi; P. Ricci; E. Truhlik
2007-02-28
Starting from the axial heavy meson exchange currents, constructed earlier in conjunction with the Bethe--Salpeter equation, we first present the axial $\\rho$--, $\\omega$-- and $a_1$ meson exchange Feynman amplitudes that satisfy the partial conservation of the axial current. Employing these amplitudes, we derive the corresponding weak axial heavy meson exchange currents in the leading order in the 1/M expansion ($M$ is the nucleon mass), suitable for the nuclear physics calculations beyond the threshold energies and with wave functions obtained by solving the Schr\\"odinger equation with one--boson exchange potentials. The constructed currents obey the nuclear form of the partial conservation of the axial current. We apply the space component of these currents in calculations of the cross sections for the disintegration of deuterons by low energy (anti)neutrinos. The deuteron and the final state nucleon--nucleon wave functions are derived (i) from a variant of the OBEPQB potential, and (ii) from the Nijmegen 93 and Nijmegen I nucleon-nucleon interaction. The extracted values of the constant $L_{1, A}$, entering the axial exchange currents of the pionless effective field theory, are in a reasonable agreement with its value predicted by the dimensional analysis.
Andersson, P. Andersson-Sunden, E.; Sjöstrand, H.; Jacobsson-Svärd, S.
2014-08-01
In nuclear boiling water reactor cores, the distribution of water and steam (void) is essential for both safety and efficiency reasons. In order to enhance predictive capabilities, void distribution assessment is performed in two-phase test-loops under reactor-relevant conditions. This article proposes the novel technique of fast-neutron tomography using a portable deuterium-tritium neutron generator to determine the time-averaged void distribution in these loops. Fast neutrons have the advantage of high transmission through the metallic structures and pipes typically concealing a thermal-hydraulic test loop, while still being fairly sensitive to the water/void content. However, commercially available fast-neutron generators also have the disadvantage of a relatively low yield and fast-neutron detection also suffers from relatively low detection efficiency. Fortunately, some loops are axially symmetric, a property which can be exploited to reduce the amount of data needed for tomographic measurement, thus limiting the interrogation time needed. In this article, three axially symmetric test objects depicting a thermal-hydraulic test loop have been examined; steel pipes with outer diameter 24 mm, thickness 1.5 mm, and with three different distributions of the plastic material POM inside the pipes. Data recorded with the FANTOM fast-neutron tomography instrument have been used to perform tomographic reconstructions to assess their radial material distribution. Here, a dedicated tomographic algorithm that exploits the symmetry of these objects has been applied, which is described in the paper. Results are demonstrated in 20 rixel (radial pixel) reconstructions of the interior constitution and 2D visualization of the pipe interior is demonstrated. The local POM attenuation coefficients in the rixels were measured with errors (RMS) of 0.025, 0.020, and 0.022 cm{sup ?1}, solid POM attenuation coefficient. The accuracy and precision is high enough to provide a useful indication on the flow mode, and a visualization of the radial material distribution can be obtained. A benefit of this system is its potential to be mounted at any axial height of a two-phase test section without requirements for pre-fabricated entrances or windows. This could mean a significant increase in flexibility of the void distribution assessment capability at many existing two-phase test loops.
ANALYSIS OF THE AXIAL GAP VS FIBERBOARD MOISTURE CONTENT IN A 9975 SHIPPING PACKAGE
Daugherty, W.
2013-09-30
The fiberboard assembly within a 9975 shipping package contains a modest amount of moisture, which can migrate to the cooler regions of the package when an internal heat load is present. Typically, this leads to increased moisture levels in the bottom fiberboard layers, along with elevated chloride levels which can leach from the fiberboard. Concerns have been raised that this condition could lead to corrosion of the stainless steel drum. It has been postulated that checking the axial gap at the top of the package against the current 1 inch maximum criterion provides a sufficient indication regarding the integrity of the fiberboard and drum. This report estimates the increase in axial gap that might be expected for a given moisture increase in the bottom fiberboard layers, and the likelihood that the increase will create a nonconforming condition that will lead to identification of the moisture increase. Using data relating the fiberboard moisture content with the degree of compaction under load, the present analysis indicates that the axial gap will increase by 0.282 inch as the bottom fiberboard layers approach the saturation point. This increase will cause approximately 58% of packages with otherwise nominal package component dimensions to fail the axial gap criterion, based on a survey of axial gap values recorded in K-Area surveillance activities. As the moisture content increases above saturation, the predicted increase in axial gap jumps to 0.405 inch, which would result in 92% or more of all packages failing the axial gap criterion. The data and analysis described in this report are specific to cane fiberboard. While it is expected that softwood fiberboard will behave similarly, such behavior has not yet been demonstrated.
PERFORMANCE IMPROVEMENT OF CROSS-FLOW FILTRATION FOR HIGH LEVEL WASTE TREATMENT
Duignan, M.; Nash, C.; Poirier, M.
2011-01-12
In the interest of accelerating waste treatment processing, the DOE has funded studies to better understand filtration with the goal of improving filter fluxes in existing cross-flow equipment. The Savannah River National Laboratory (SRNL) was included in those studies, with a focus on start-up techniques, filter cake development, the application of filter aids (cake forming solid precoats), and body feeds (flux enhancing polymers). This paper discusses the progress of those filter studies. Cross-flow filtration is a key process step in many operating and planned waste treatment facilities to separate undissolved solids from supernate slurries. This separation technology generally has the advantage of self-cleaning through the action of wall shear stress created by the flow of waste slurry through the filter tubes. However, the ability of filter wall self-cleaning depends on the slurry being filtered. Many of the alkaline radioactive wastes are extremely challenging to filtration, e.g., those containing compounds of aluminum and iron, which have particles whose size and morphology reduce permeability. Unfortunately, low filter flux can be a bottleneck in waste processing facilities such as the Savannah River Modular Caustic Side Solvent Extraction Unit and the Hanford Waste Treatment Plant. Any improvement to the filtration rate would lead directly to increased throughput of the entire process. To date increased rates are generally realized by either increasing the cross-flow filter axial flowrate, limited by pump capacity, or by increasing filter surface area, limited by space and increasing the required pump load. SRNL set up both dead-end and cross-flow filter tests to better understand filter performance based on filter media structure, flow conditions, filter cleaning, and several different types of filter aids and body feeds. Using non-radioactive simulated wastes, both chemically and physically similar to the actual radioactive wastes, the authors performed several tests to demonstrate increases in filter performance. With the proper use of filter flow conditions and filter enhancers, filter flow rates can be increased over rates currently realized today.
SOUND TRANSMISSION IN SLOWLY VARYING CIRCULAR AND ANNULAR LINED DUCTS WITH FLOW a
Eindhoven, Technische Universiteit
SOUND TRANSMISSION IN SLOWLY VARYING CIRCULAR AND ANNULAR LINED DUCTS WITH FLOW a S.W. Rienstra/CEAS Aeroacoustics Conference, June 24, 1998, Toulouse ABSTRACT Sound transmission through straight circular ducts by a modal expansion. A natural ex tension for ducts with axially slowly varying properties (diameter
Three-dimensional turbulent swirling flow in a cylinder: Experiments and computations
Gupta, Amit
and an axial exhaust called a vortex finder tube. Due to the centrif- ugal action of the fluid from fluid forms an inner vortex and exits through the vortex finder tube located at the top. The out- flow through the cone is usually called the underflow and that through the vortex finder tube the overflow
Hsu, Cheng-Ting (Ames, IA)
1984-01-01
A tornado type wind turbine has a vertically disposed wind collecting tower with spaced apart inner and outer walls and a central bore. The upper end of the tower is open while the lower end of the structure is in communication with a wind intake chamber. An opening in the wind chamber is positioned over a turbine which is in driving communication with an electrical generator. An opening between the inner and outer walls at the lower end of the tower permits radially flowing air to enter the space between the inner and outer walls while a vertically disposed opening in the wind collecting tower permits tangentially flowing air to enter the central bore. A porous portion of the inner wall permits the radially flowing air to interact with the tangentially flowing air so as to create an intensified vortex flow which exits out of the top opening of the tower so as to create a low pressure core and thus draw air through the opening of the wind intake chamber so as to drive the turbine.
Axial seal system for a gas turbine steam-cooled rotor
Mashey, Thomas Charles (Anderson, SC)
2002-01-01
An axial seal assembly is provided at the interface between adjacent wheels and spacers of a gas turbine rotor and disposed about tubes passing through openings in the rotor adjacent the rotor rim and carrying a thermal medium. Each seal assembly includes a support bushing for supporting a land of the thermal medium carrying tube, an axially registering seat bushing disposed in the opposed opening and a frustoconical seal between the seal bushing and seat. The seal bushing includes a radial flange having an annular recess for retaining the outer diameter edge of the seal, while the seat bushing has an axially facing annular surface forming a seat for engagement by the inner diameter edge of the seal.
Flexural support member having a high ratio of lateral-to-axial stiffness
Haas, W.M.B.
1983-06-23
A convoluted flexible support structure is provided which is capable of supplying a lateral to axial spring rate in excess of 1000 to 1. A support member in the form of a steel disc having a specified number of rather large radius, concentric convolutions and a thickness in the range of from about 0.01 to 0.02 inch has an axial stiffness of about 50 pounds/inch while the lateral stiffness is about 100,000 pounds/inch. The support member may be used to support a vibration device where the lateral motion of the vibrator must be highly restricted while providing relatively free axial displacement of about +-0.25 inch.
Production of low axial energy spread ion beams with multicusp sources
Lee, Y.H.Y.
1998-05-01
Multicusp ion sources are capable of producing ions with low axial energy spread which are necessary in applications such as: ion projection lithography (IPL) and focused ion beams for the next generation lithographic tools and nuclear science experiments such as radioactive ion beam production. The axial ion energy spread for multicusp source is approximately 6 eV which is too large for IPL and radioactive ion beam applications. The addition of a magnetic filter which consists of a pair of permanent magnets to the multicusp source reduces the energy spread considerably. The reduction is due to the improvement in the uniformity of the axial plasma potential distribution in the discharge region. Axial ion energy spread of the filament driven ion source has been measured using three different techniques. In all cases, it was found to be less than 2 eV. Energy spread of the radio frequency (RF) driven source has also been explored, and it was found to be less than 3 eV with the proper RF-shielding. A new multicusp source configuration has been designed and constructed to further reduce the energy spread. To achieve a more uniform axial plasma potential distribution, a cylindrical magnetic filter has been designed and constructed for a 2-cm-diameter source. This new source configuration, the co-axial source, is new in its kind. The energy spread in this source has been measured to be a record low of 0.6 eV. Because of the novelty of this device, some plasma parameters inside the source have been studied. Langmuir probe has been used to measure the plasma potential, the electron temperature and the density distribution.
An axially propagating two-stream instability in the Hall thruster plasma
Tsikata, S., E-mail: sedina.tsikata@cnrs-orleans.fr [ICARE, CNRS (UPR 3021), 1C ave. de la Recherche Scientifique, 45071 Orléans (France); Cavalier, J. [Institute of Plasma Physics ASCR, Prague (Czech Republic); Héron, A. [CPHT, CNRS (UMR 7644), Ecole Polytechnique, Route de Saclay, 91128 Palaiseau (France); Honoré, C.; Grésillon, D. [LPP, CNRS (UMR 7648), Ecole Polytechnique-Univ. Paris-Sud-UPMC Univ. Paris 06, Route de Saclay, 91128 Palaiseau (France); Lemoine, N.; Coulette, D. [IJL, CNRS (UMR 7198), Université de Lorraine, BP 70239, 54506 Vandoeuvre-lès-Nancy (France)
2014-07-15
Collective Thomson scattering experiments reveal the presence of high-frequency, axial electron density fluctuations at millimetric wavelengths in the Hall thruster plasma. The properties of these fluctuations are investigated experimentally and via linear kinetic theory. The relative drift of electrons and ions in the axial direction is found to be insufficient to cause excitation of the observed mode. Instead, the mode is determined to be a two-stream instability arising due to the velocity difference between singly and doubly charged ion populations in the plume.
Van den Engh, G.
1995-11-07
A Faraday cage is described which encloses the flow chamber of a cytometer. Ground planes associated with each field deflection plate inhibit electric fields from varying the charge on designated events/droplets and further concentrates. They also increase forces applied to a passing charged event for accurate focus while concomitantly inhibiting a potential shock hazard. 4 figs.
OPPDIF: A Fortran program for computing opposed-flow diffusion flames
Lutz, A.E.; Kee, R.J.; Grcar, J.F.; Rupley, F.M.
1997-05-01
OPPDIF is a Fortran program that computes the diffusion flame between two opposing nozzles. A similarity transformation reduces the two-dimensional axisymmetric flow field to a one-dimensional problem. Assuming that the radial component of velocity is linear in radius, the dependent variables become functions of the axial direction only. OPPDIF solves for the temperature, species mass fractions, axial and radial velocity components, and radial pressure gradient, which is an eigenvalue in the problem. The TWOPNT software solves the two-point boundary value problem for the steady-state form of the discretized equations. The CHEMKIN package evaluates chemical reaction rates and thermodynamic and transport properties.
Axial obliquity control on the greenhouse carbon budget through middle-to high-latitude reservoirs
Meyers, Stephen R.
Axial obliquity control on the greenhouse carbon budget through middle- to high-latitude reservoirs for past greenhouse climates. Carbon-isotope data indicate systematic, million-year-scale transfers-stable character, they might have provided an important control on the dynamics and stability of the greenhouse
Nucleon axial charge from quenched lattice QCD with domain wall fermions
Shoichi Sasaki; Kostas Orginos; Shigemi Ohta; Tom Blum; for the RBCK Collaboration
2003-07-18
We present a quenched lattice calculation of the nucleon isovector vector and axial-vector charges gV and gA. The chiral symmetry of domain wall fermions makes the calculation of the nucleon axial charge particularly easy since the Ward-Takahashi identity requires the vector and axial-vector currents to have the same renormalization, up to lattice spacing errors of order O(a^2). The DBW2 gauge action provides enhancement of the good chiral symmetry properties of domain wall fermions at larger lattice spacing than the conventional Wilson gauge action. Taking advantage of these methods and performing a high statistics simulation, we find a significant finite volume effect between the nucleon axial charges calculated on lattices with (1.2 fm)^3 and (2.4 fm)^3 volumes (with lattice spacing, a, of about 0.15 fm). On the large volume we find gA = 1.212 +/- 0.027(statistical error) +/- 0.024(normalization error). The quoted systematic error is the dominant (known) one, corresponding to current renormalization. We discuss other possible remaining sources of error. This theoretical first principles calculation, which does not yet include isospin breaking effects, yields a value of gA only a little bit below the experimental one, 1.2670 +/- 0.0030.
Chadwick, Bill
Vertical deformation monitoring at Axial Seamount since its 1998 eruption using deep-sea pressure geodesy; bottom pressure recorder 1. Introduction The purpose of vertical deformation monitoring at active.W. Chadwick). Journal of Volcanology and Geothermal Research 150 (2006) 313327 www
Single and Tandem Axial p-i-n Nanowire Photovoltaic Devices
Xie, Xiaoliang Sunney
Single and Tandem Axial p-i-n Nanowire Photovoltaic Devices Thomas J. Kempa,, Bozhi Tian,, Dong Rip-i-n+-p+-i-n silicon nanowire (SiNW) photovoltaic elements. Scanning electron microscopy images of selectively etched. Finally, a novel single SiNW tandem solar cell consisting of synthetic integration of two photovoltaic
Novel LINAC II electrode geometry to create an axial field in a multipole ion guide.
Ens, Werner
and determines the upper m/z transmission limit. A conventional LINAC has a quadrupolar DC field distortion while like the LINAC(SCIEX) suffer from a reduced mass transmission window. A wide transmission window. The axial field is created by applying the same DC potential UL to all four T-shaped electrodes
Resonance behavior of liquid bridges under axial and lateral oscillating total body forces
Taylor, Philip L.
bridges that are magnetically levitated in air against gravity are subjected to either axial or lateral of the technique of time-varying magnetic levitation is that problems associated with the influence of the outer is a simple configuration that is ideal for the study of static properties (Meseguer 1983; Meseguer and Sanz
Cost effective combined axial fan and throttling valve control of ventilation rate
Sengun, Mehmet Haluk
Cost effective combined axial fan and throttling valve control of ventilation rate C.J. Taylor 1 P. In partic- ular, it develops a unique fan and throttling valve control system for a 22m3 test chamber, the throttling valve is employed to restrict airflow at the outlet, so generating a higher static pressure differ
Three-dimensional model and simulation of vacuum arcs under axial magnetic fields
Wang Lijun; Jia Shenli; Zhou Xin; Wang Haijing; Shi Zongqian
2012-01-15
In this paper, a three-dimensional (3d) magneto-hydro-dynamic (MHD) model of axial magnetic field vacuum arcs (AMFVAs) is established. Based on this model, AMFVAs are simulated and analyzed. Three-dimensional spatial distributions of many important plasma parameters and electric characteristics in AMFVAs can be obtained, such as ion number density, ion temperature, electron temperature, plasma pressure, current densities along different directions (x, y, and z), ion velocities along different directions, electric fields strength along different directions, and so on. Simulation results show that there exist significant spiral-shaped rotational phenomena in the AMFVAs, this kind of rotational phenomenon also can be verified by the many related experiments (AMFVAs photographs, especially for stronger AMF strength). For current simulation results of AMFVAs, the maximal rotational velocity at anode side is about 1100 m/s. Radial electric field is increased from arc center to arc edge; axial electric field is decreased from cathode side to anode side. Radial electric field at arc edge can be larger than axial electric field. Azimuthal electric field in most regions is much smaller than radial and axial electric field, but it can reach about 1.19 kV/m. Radial magnetic field is the smallest one compared with other components, it reaches to maximum value at the position near to anode, it can influence arc characteristics.
Wetmore, Paul H.
Late Quaternary constructional development of the Axial Volcanic Zone, eastern Snake River Plain volcanic ridge that trends northeast across the middle of the eastern Snake River Plain, and acts Snake River Plain: the AVZ, the Big Lost Trough to the north, and the Arco-Big Southern Butte (ABSB
Interpretation of Scalar and axial mesons in LHCb from an historical perspective
F. E. Close; A. Kirk
2015-03-24
LHCb measurements of $B_{d,s} \\to J/\\psi + X$ are shown to be consistent with historical data on scalar and axial mesons below 2 GeV. This is in contrast to some recent interpretations of these data. Further tests of our hypotheses in other $B_{u,d,s} \\to J/\\psi + X$ decay modes are suggested.
Influence of constraints on axial growth reduction of cylindrical Li-ion battery electrode particles
Jeevanjyoti Chakraborty; Colin P. Please; Alain Goriely; S. Jonathan Chapman
2014-11-24
Volumetric expansion of silicon anode particles in a lithium-ion battery during charging may lead to the generation of undesirable internal stresses. For a cylindrical particle such growth may also lead to failure by buckling if the expansion is constrained in the axial direction due to other particles or supporting structures. To mitigate this problem, the possibility of reducing axial growth is investigated theoretically by studying simple modifications of the solid cylinder geometry. First, an annular cylinder is considered with lithiation either from the inside or from the outside. In both cases, the reduction of axial growth is not found to be significant. Next, explicit physical constraints are studied by addition of a non-growing elasto-plastic material: first, an outer annular constraint on a solid silicon cylinder, and second a rod-like inner constraint for an annular silicon cylinder. In both cases, it is found that axial growth can be reduced if the yield stress of the constraining material is significantly higher than that of silicon and/or the thickness of the constraint is relatively high. Phase diagrams are presented for both the outer and the inner constraint cases to identify desirable operating zones. Finally, to interpret the phase diagrams and isolate the key physical principles two different simplified models are presented and are shown to recover important qualitative trends of the numerical simulation results.
Optical breakdown in transparent media with adjustable axial length and location
Palanker, Daniel
Optical breakdown in transparent media with adjustable axial length and location Ilya Toytman,1 of transparent materials. It might be useful for ophthalmic surgical applications including cataract surgery430 (2006). 10. O. Brzobohatý, T. Cizmár, and P. Zemánek, "High quality quasi-Bessel beam generated by round
de Gispert, Adrià
Paper Hydrogen bonding preference of equatorial versus axial hydroxyl groups in pyran of the hydrogen bonding counts in crystalline pyranose monosaccharides, we noticed that equatorial hydroxyls formed more hydrogen bonds, on average, than axial groups. A survey of the Cambridge Structural Database
structures were considered. Axial load - bending moment interaction curves are presented. The paper presents1 Experimental and Analytical Modeling of Concrete-Filled FRP Tubes Subjected to Combined Bending and Axial Loads Amir Fam 1 , Bart Flisak 2 and Sami Rizkalla 3 Abstract This paper presents test results
Preventing Buckling of Slender Cylindrical Structures by Internal Viscous Flows
Max Linshits; Amir D. Gat
2015-02-10
Viscous flows within an elastic structure apply stress on the solid-liquid interface. The stress-field created by the viscous flow can be utilized to counter stress created by external forces and thus may be applied as a tool for delaying the onset of structural failure. To illustrate this concept we study viscous flow within an elastic cylinder under compressive axial force. We obtain a closed-form expression showing an approximately linear relation between the critical buckling load and the liquid inlet pressure. Our results are validated by numerical computations. We discuss future research directions of fluid-solid composite materials which create flow under external stress, yielding enhanced resistance to structural failure.
Evans, MDD; Lyons, Richard K.
2006-01-01
Understanding Order Flow October 2005 Martin D. D. Evans 1Rate Fundamentals and Order Flow, typescript, Georgetown2005), Customer Order Flow and Exchange Rate Movements: Is
Khater, A.H.; Moawad, S.M.; Callebaut, D.K. [Department of Mathematics, Faculty of Science, Cairo University, Beni-Suef (Egypt); Departement Natuurkunde, Campus Drie Eiken, Universiteit Antwerpen - UA, B-2610 Antwerpen (Belgium)
2005-01-01
The equilibrium and Lyapunov stability properties for two-dimensional ideal magnetohydrodynamic (MHD) plasmas with incompressible and homogeneous (i.e., constant density) flows are investigated. In the unperturbed steady state, both the velocity and magnetic field are nonzero and have three components in a Cartesian coordinate system with translational symmetry (i.e., one ignorable spatial coordinate). It is proved that (a) the solutions of the ideal MHD steady state equations with incompressible and homogeneous flows in the plane are also valid for equilibria with the axial velocity component being a free flux function and the axial magnetic field component being a constant (b) the conditions of linearized Lyapunov stability for these MHD flows in the planar case (in which the fields have only two components) are also valid for symmetric equilibria that have a nonplanar velocity field component as well as a nonplanar magnetic field component. On using the method of convexity estimates, nonlinear stability conditions are established.
Flow rule of dense granular flows down a rough incline
Tamas Borzsonyi; Robert E. Ecke
2007-07-09
We present experimental findings on the flow rule for granular flows on a rough inclined plane using various materials including sand and glass beads of various sizes and four types of copper particles with different shapes. We characterize the materials by measuring $h_s$ (the thickness at which the flow subsides) as a function of the plane inclination $\\theta$ on various surfaces. Measuring the surface velocity $u$ of the flow as a function of flow thickness $h$, we find that for sand and glass beads the Pouliquen flow rule $u/\\sqrt{gh} \\sim \\beta h/h_s$ provides reasonable but not perfect collapse of the $u(h)$ curves measured for various $\\theta$ and mean particle diameter $d$. Improved collapse is obtained for sand and glass beads by using a recently proposed scaling of the form $u/\\sqrt{gh} =\\beta \\cdot h \\tan^2\\theta /h_s\\ \\tan^2\\theta_1$ where $\\theta_1$ is the angle at which the $h_s(\\theta)$ curves diverge. Measuring the slope $\\beta$ for ten different sizes of sand and glass beads, we find a systematic, strong increase of $\\beta$ with the divergence angle $\\theta_1$ of $h_s$. The copper materials with different shapes are not well described by either flow rule with $u \\sim h^{3/2}$.
\\(?\\) vector and axial-vector spectral functions in the extended linear sigma model
A. Habersetzer; Francesco Giacosa
2015-04-16
The extended linear sigma model describes the vacuum phenomenology of scalar, pseudoscalar, vector and axial-vector mesons at energies \\(\\simeq 1\\text{ GeV}\\). We combine the chiral \\(U(2)_L\\times U(2)_R\\) symmetry of this model with a local \\(SU(2)_L\\times U(1)_Y\\) symmetry and obtain a gauge invariant effective description for electroweak interaction of hadrons in the vacuum. Vector and axial-vector spectral functions can be described well by two intermediate resonances \\(\\rho\\) and \\(a_1\\). They are implemented into this model as chiral partners and yield the predominant contributions to both spectral functions. However, the contributions that arise from the non-resonant decay channels of the weak charged \\(W\\) bosons are essential for reproducing the lineshapes of the spectral functions.
Li Wei; Liu Yonggui; Shu Ting; Yang Hanwu; Fan Yuwei; Yuan Chengwei; Zhang Jun [College of Optoelectric Science and Engineering, National University of Defense Technology, Changsha, Hunan 410073 (China)
2012-01-15
A compact relativistic magnetron with axial microwave radiation is experimentally investigated. Under the modified magnetic field distribution, only connecting a special horn antenna in the axial direction, the relativistic magnetron can stably radiate high power and high efficiency microwaves. The total length of the device is {approx}0.3 m, and the volume is {approx}0.014m{sup 3}. In such working condition that the applied voltage is 539 kV and the magnetic field is {approx}0.38 T, the output microwave power is {approx}1.24 GW. Correspondingly, the total efficiency is about 34.1%. The radiating frequency is 2.35GHz, which is in agreement with the {pi} mode frequency of the theoretical expectation.
Radiofrequency hydrogen ion source with permanent magnets providing axial magnetic field
Oikawa, Kohei, E-mail: oikawa@ecei.tohoku.ac.jp; Saito, Yuta; Komizunai, Shota; Takahashi, Kazunori; Ando, Akira [Department of Electrical Engineering, Tohoku University, Sendai 980-8579 (Japan)] [Department of Electrical Engineering, Tohoku University, Sendai 980-8579 (Japan)
2014-02-15
Uniform axial magnetic field of about 70 G is applied to a radiofrequency (rf) hydrogen ion source by arrays of permanent magnets. The plasma density and electron temperature downstream of the source and near the magnetic filter are compared with those in the previously described ion source, where the axial field has been applied by two solenoids. The source is operated at ?350 kHz and above 10 kW rf power with a field-effect-transistor-based invertor power supply in 1.5 Pa hydrogen. The results show that the plasma density of ?10{sup 19} m{sup ?3} near the source exit and ?10{sup 18} m{sup ?3} near the magnetic filter can be obtained, which are higher than those with the solenoids.
Axial magnetic field generation by intense circularly polarized laser pulses in underdense plasmas
Naseri, N.; Rozmus, W. [Theoretical Physics Institute, University of Alberta, Edmonton, Alberta T6G 2J1 (Canada); Bychenkov, V. Yu. [Theoretical Physics Institute, University of Alberta, Edmonton, Alberta T6G 2J1 (Canada); P. N. Lebedev Physics Institute, Russian Academy of Sciences, Moscow 119991 (Russian Federation)
2010-08-15
Axial magnetic field generation by intense circularly polarized laser beams in underdense plasmas has been studied with three-dimensional particle-in-cell simulations and by means of theoretical analysis. Comparisons between analytical models and simulation results have identified an inverse Faraday effect as the main mechanism of the magnetic field generation in inhomogeneous plasmas. The source of azimuthal nonlinear currents and of the axial magnetic field depends on the transverse inhomogeneities of the electron density and laser intensity. The fields reach a maximum strength of several tens of megagauss for laser pulses undergoing relativistic self-focusing and channeling in moderately relativistic regime. Ultrarelativistic laser conditions inhibit magnetic field generation by directly reducing a source term and by generating fully evacuated plasma channels.
Baker, W.E.; Bennett, J.G.; Babcock, C.D.
1983-01-01
Six steel shells having nuclear containment-like features were fabricated and loaded to failure with an offset axial load. The shells of R/t = 500 buckled plastically. Four of the shells had reinforced circular cutouts. These penetrations were sized to cut no ring-stiffener, a single, two- or three-ring stiffeners. Reinforcing and framing around the penetrations were based upon the area-replacement rule of the applicable portion of the American Society for Mechanical Engineers (ASME) Boiler and Pressure Vessel Code and were of a design to simulate actual practice for nuclear steel containments. Prior to testing, imperfections were measured and strain gages were applied to determine information on load distribution at the ends of the cylinder and strain fields at areas likely to buckle. Buckling loads were determined for an axial load applied with an eccentricity of R/2 where R is the cylinder radius.
Dunn, J.C.; Hardee, H.C.; Striker, R.P.
1984-01-09
A convective heat flow probe device is provided which measures heat flow and fluid flow magnitude in the formation surrounding a borehole. The probe comprises an elongate housing adapted to be lowered down into the borehole; a plurality of heaters extending along the probe for heating the formation surrounding the borehole; a plurality of temperature sensors arranged around the periphery of the probe for measuring the temperature of the surrounding formation after heating thereof by the heater elements. The temperature sensors and heater elements are mounted in a plurality of separate heater pads which are supported by the housing and which are adapted to be radially expanded into firm engagement with the walls of the borehole. The heat supplied by the heater elements and the temperatures measured by the temperature sensors are monitored and used in providing the desired measurements. The outer peripheral surfaces of the heater pads are configured as segments of a cylinder and form a full cylinder when taken together. A plurality of temperature sensors are located on each pad so as to extend along the length and across the width thereof, with a heating element being located in each pad beneath the temperature sensors. An expansion mechanism driven by a clamping motor provides expansion and retraction of the heater pads and expandable packet-type seals are provided along the probe above and below the heater pads.
The Flow of Power-Law Fluids in Axisymmetric Corrugated Tubes
Sochi, Taha
2010-01-01
In this article we present an analytical method for deriving the relationship between the pressure drop and flow rate in laminar flow regimes, and apply it to the flow of power-law fluids through axially-symmetric corrugated tubes. The method, which is general with regards to fluid and tube shape within certain restrictions, can also be used as a foundation for numerical integration where analytical expressions are hard to obtain due to mathematical or practical complexities. Five converging-diverging geometries are used as examples to illustrate the application of this method.
The Flow of Power-Law Fluids in Axisymmetric Corrugated Tubes
Taha Sochi
2010-06-13
In this article we present an analytical method for deriving the relationship between the pressure drop and flow rate in laminar flow regimes, and apply it to the flow of power-law fluids through axially-symmetric corrugated tubes. The method, which is general with regards to fluid and tube shape within certain restrictions, can also be used as a foundation for numerical integration where analytical expressions are hard to obtain due to mathematical or practical complexities. Five converging-diverging geometries are used as examples to illustrate the application of this method.
Charmless Hadronic B Decays into Vector, Axial Vector and Tensor Final States at BaBar
Gandini, Paolo; /Milan U. /INFN, Milan
2012-04-06
We present experimental measurements of branching fraction and longitudinal polarization fraction in charmless hadronic B decays into vector, axial vector and tensor final states with the final dataset of BABAR. Measurements of such kind of decays are a powerful tool both to test the Standard Model and search possible sources of new physics. In this document we present a short review of the last experimental results at BABAR concerning charmless quasi two-body decays in final states containing particles with spin 1 or spin 2 and different parities. This kind of decays has received considerable theoretical interest in the last few years and this particular attention has led to interesting experimental results at the current b-factories. In fact, the study of longitudinal polarization fraction f{sub L} in charmless B decays to vector vector (VV), vector axial-vector (VA) and axial-vector axial-vector (AA) mesons provides information on the underlying helicity structure of the decay mechanism. Naive helicity conservation arguments predict a dominant longitudinal polarization fraction f{sub L} {approx} 1 for both tree and penguin dominated decays and this pattern seems to be confirmed by tree-dominated B {yields} {rho}{rho} and B{sup +} {yields} {Omega}{rho}{sup +} decays. Other penguin dominated decays, instead, show a different behavior: the measured value of f{sub L} {approx} 0.5 in B {yields} {phi}K* decays is in contrast with naive Standard Model (SM) calculations. Several solutions have been proposed such as the introduction of non-factorizable terms and penguin-annihilation amplitudes, while other explanations invoke new physics. New modes have been investigated to shed more light on the problem.
High-Efficiency Deflection of High-Energy Protons through Axial Channeling in a Bent Crystal
Scandale, Walter; Baricordi, Stefano; Dalpiaz, Pietro; Fiorini, Massimiliano; Guidi, Vincenzo; Mazzolari, Andrea; Della Mea, Gianantonio; Milan, Riccardo; Ambrosi, Giovanni; Bertucci, Bruna; Burger, William J; Zuccon, Paolo; Cavoto, Gianluca; Luci, Claudio; Santacesaria, Roberta; Valente, Paolo; Vallazza, Erik; Afonin, Alexander G; Chesnokov, Yury A; Maisheev, Vladimir A; Yazynin, Igor A; Kovalenko, Alexander D; Taratin, Alexander M; Denisov, Alexander S; Gavrikov, Yury A; Ivanov, Yuri M; Lapina, Lyubov P; Malyarenko, Liudmila G; Skorobogatov, Vyacheslav V; Suvorov, Vsevolod M; Vavilov, Sergey A; Bolognini, Davide; Hasan, Said; Mozzanica, Aldo; Prest, Michela
2008-01-01
Beam deflection due to axial channeling in a silicon crystal bent along the [111] axis was observed with 400??GeV/c protons at the CERN Super Proton Synchrotron. The condition for doughnut scattering of protons by the atomic strings of the crystal was attained. Such a condition allowed one to observe a beam deflection of 50???rad with about 30% efficiency. The contribution of hyperchanneled states of protons to the observed beam deflection was less than 2% according to simulation results.
Scattering of particles by neutron stars: Time-evolutions for axial perturbations
V. Ferrari; K. D. Kokkotas
2000-08-23
The excitation of the axial quasi-normal modes of a relativistic star by scattered particles is studied by evolving the time dependent perturbation equations. This work is the first step towards the understanding of more complicated perturbative processes, like the capture or the scattering of particles by rotating stars. In addition, it may serve as a test for the results of the full nonlinear evolution of binary systems.
Fe XII STALKS AND THE ORIGIN OF THE AXIAL FIELD IN FILAMENT CHANNELS
Wang, Y.-M.; Sheeley, N. R. Jr.; Stenborg, G. E-mail: neil.sheeley@nrl.navy.mil
2013-06-10
Employing Fe XII images and line-of-sight magnetograms, we deduce the direction of the axial field in high-latitude filament channels from the orientation of the adjacent stalklike structures. Throughout the rising phase of the current solar cycle 24, filament channels poleward of latitude 30 Degree-Sign overwhelmingly obeyed the hemispheric chirality rule, being dextral (sinistral) in the northern (southern) hemisphere, corresponding to negative (positive) helicity. During the deep minimum of 2007-2009, the orientation of the Fe XII stalks was often difficult to determine, but no obvious violations of the rule were found. Although the hemispheric trend was still present during the maximum and early declining phase of cycle 23 (2000-2003), several high-latitude exceptions were identified at that time. From the observation that dextral (sinistral) filament channels form through the decay of active regions whose Fe XII features show a counterclockwise (clockwise) whorl, we conclude that the axial field direction is determined by the intrinsic helicity of the active regions. In contrast, generation of the axial field component by the photospheric differential rotation is difficult to reconcile with the observed chirality of polar crown and circular filament channels, and with the presence of filament channels along the equator. The main role of differential rotation in filament channel formation is to expedite the cancellation of flux and thus the removal of the transverse field component. We propose further that, rather than being ejected into the heliosphere, the axial field is eventually resubmerged by flux cancellation as the adjacent unipolar regions become increasingly mixed.
Spectral Remittances of Chiral Sculptured Zirconia Thin Films in Non-axial propagation
Babaei, Ferydon; 10.1080/09500340802130597
2010-01-01
The transmission and reflection spectra from a right-handed chiral sculptured zirconia thin film are calculated using the piecewise homogeneity approximation method and the Bruggeman homogenization formalism and considering that the dispersion of dielectric function happens in non-axial propagation state. First and second Bragg peaks were observed in cross-poloraized reflectances and it became clear that increasing the azimutal angle affects the spectra of linearly polarized state significantly. This is opposite to circularly polarized state.
Manipulating Magnetism: Ru-2(5+) Paddlewheels Devoid of Axial Interactions
Chiarella, Gina M [Texas A& M University; Cotton, F. A. [Texas A& M University; Murillo, Carlos A [Texas A& M University; Ventura, Karen [University of Texas at El Paso; Vilagran, Dino [University of Texas at El Paso; Wang, Xiaoping [ORNL
2014-01-01
Variable-temperature magnetic and structural data of two pairs of diruthenium isomers, one pair having an axial ligand and the formula Ru-2(DArF)(4)Cl (where DArF is the anion of a diarylformamidine isomer and Ar = p-anisyl or m-anisyl) and the other one being essentially identical but devoid of axial ligands and having the formula [Ru-2(DArF)(4)]BF4, show that the axial ligand has a significant effect on the electronic structure of the diruthenium unit. Variable temperature crystallographic and magnetic data as well as density functional theory calculations unequivocally demonstrate the occurrence of pi interactions between the p orbitals of the chlorine ligand and the pi* orbitals in the Ru-2(5+) units. The magnetic and structural data are consistent with the existence of combined ligand sigma/metal sigma and ligand p pi/metal-d pi interactions. Electron paramagnetic resonance data show unambiguously that the unpaired electrons are in metal-based molecular orbitals.
Hacker, Randi; Tsutsui, William
2007-03-14
Sox spent a hundred mil to acquire pitcher Daisuke Matsuzaka; they probably weren't even aware that he is a Type O and that they make the best bankers, politicians and... you guessed it... professional baseball players. #ceas #hacker #japan #tsutsuien...
Noah D. Manring Mechanical and Aerospace Engineering,
Manring, Noah D.
with an odd number of pistons. In the industry, where axial-piston pumps are designed, a cer- tain amount, MO 65211 The Discharge Flow Ripple of an Axial-Piston Swash-Plate Type Hydrostatic Pump This research examines the idealized and actual flow-ripple of an axial-piston swash- plate type hydrostatic pump
The effect of plasma flow on line-tied magnetohydrodynamic modes
Arcudi, Francesco [Dipartimento di Energetica, Politecnico di Torino, 10129 Torino (Italy); Delzanno, Gian Luca; Finn, John M. [T-5, Applied Mathematics and Plasma Physics Group, Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States)
2010-06-15
The linear stability of a linear pinch to kink modes with line-tying boundary conditions and equilibrium axial flow is studied. Numerical results in visco-resistive magnetohydrodynamics show that for long plasmas, in which the line-tying stabilization effect is weak, plasma flow is stabilizing. For shorter plasmas, near the length at which line-tying stabilizes the mode for zero flow, the flow can be destabilizing. A simple model using reduced ideal magnetohydrodynamics with a step-function current density and an even simpler one-dimensional sound wave model with equilibrium flow elucidate these effects. It is concluded that: (1) The stabilization in long plasmas is due to convective stabilization; (2) the destabilization for short plasmas can be explained using a picture involving the coupling of two stable waves, one propagating in the forward direction and one in the backward direction; and (3) strong magnetic shear suppresses the flow destabilization for short plasmas.
Taylor, Alexander M.
The enantioselective ?-arylation and ?-vinylation of oxindoles catalyzed by Pd and a biarylmonophosphine ligand with both axial and phosphorus-based chirogenicity is reported. The resultant quaternary carbon stereocenters ...
Varghese, Joshua
2011-08-02
constant (TC) have been developed. The axial strain TC is a parameter that is related to the viscoelastic and poroelastic behavior of tissues. Estimation of this parameter can be done using curve fitting methods. However, the effect of temporal...
Static and dynamic characteristics for a two-axial-groove bearing and a pressure-dam bearing
Al Jughaiman, Bader K.
2009-06-02
This thesis compares experimental static and dynamic force characteristics for a two-axial-groove bearing and a pressure-dam bearing without a relief track. The thesis also compares experimental results to predictions from a numerical analysis...
Large-scale flow generation by inhomogeneous helicity
Yokoi, Nobumitsu
2015-01-01
The effect of kinetic helicity (velocity--vorticity correlation) on turbulent momentum transport is investigated. The turbulent kinetic helicity (pseudoscalar) enters into the Reynolds stress (mirrorsymmetric tensor) expression in the form of a helicity gradient as the coupling coefficient for the mean vorticity and/or the angular velocity (axial vector), which suggests the possibility of mean-flow generation in the presence of inhomogeneous helicity. This inhomogeneous helicity effect, which was previously confirmed at the level of a turbulence- or closure-model simulation, is examined with the aid of direct numerical simulations of rotating turbulence with non-uniform helicity sustained by an external forcing. The numerical simulations show that the spatial distribution of the Reynolds stress is in agreement with the helicity-related term coupled with the angular velocity, and that a large-scale flow is generated in the direction of angular velocity. Such a large-scale flow is not induced in the case of hom...
Urquiza, Eugenio
2009-01-01
for Compact Plate-Type Heat Exchangers. ” American Institutethese conditions, plate-type heat exchangers with small flowHeatric plate-type compact heat exchanger showing multiple
An investigation of two-phase gas-liquid slug flow
Mao, Z.
1988-01-01
Both experimental and numerical approaches were used in this study to explore the hydrodynamics of slug flow and its transition to the churn flow pattern. Extensive experimental data were taken using conductance wires, an electrochemical probe and a phase detection probe to simultaneously provide the axial void fraction distribution in the liquid slug, the axial profile of wall shear stress, the shape of the Taylor bubble, and the length and velocity of liquid slugs and Taylor bubbles. Data were collected for single Taylor bubbles rising in stagnant and flowing liquid as well as for continuous slug flow. A numerical method was developed for computing the flow field in the liquid slug and the falling film around a Taylor bubble. The field is first computed with a designated rise velocity and shape profile. Then the shape is adjusted to satisfy a constant pressure conditions at the free surface. It is shown that from an infinity of possible solutions the physically realistic Taylor bubble must have a rise velocity which creases a spherical nose in the vicinity of the vertex. The combination of experimental measurements and the numerical simulations reveal the details of slug flow and suggest that a circulating eddy exists at the top of a liquid slug. In contrast to conventional belief, churn flow is found to be better perceived as an extension of slug flow, instead of a distinct flow pattern. Numerical simulations for the flow around a single Taylor bubble give results in good agreement with the measured shape and the rise velocity of the bubble in both stagnant and flowing liquid for both turbulent and laminar flow. Similar computations for a train of bubbles show qualitative agreement with experiment.
Hoffman, E.L.; Ammerman, D.J.
1995-04-01
A series of tests investigating dynamic pulse buckling of a cylindrical shell under axial impact is compared to several 2D and 3D finite element simulations of the event. The purpose of the work is to investigate the performance of various analysis codes and element types on a problem which is applicable to radioactive material transport packages, and ultimately to develop a benchmark problem to qualify finite element analysis codes for the transport package design industry. During the pulse buckling tests, a buckle formed at each end of the cylinder, and one of the two buckles became unstable and collapsed. Numerical simulations of the test were performed using PRONTO, a Sandia developed transient dynamics analysis code, and ABAQUS/Explicit with both shell and continuum elements. The calculations are compared to the tests with respect to deformed shape and impact load history.
Regionally compartmented groundwater flow on Mars Keith P. Harrison1
Harrison, Keith
Regionally compartmented groundwater flow on Mars Keith P. Harrison1 and Robert E. Grimm1 Received] Groundwater flow on Mars likely contributed to the formation of several types of morphologic and mineralogic of groundwater flow required for their formation. For groundwater simulation purposes, a global Martian aquifer
Effective Blame for Information-Flow Violations Trent Jaeger
Seshia, Sanjit A.
for information-flow blame that can explain the source of such security errors in code. This model is implemented]: Formal meth- ods--error reporting, information-flow, security-typed lan- guages 1. INTRODUCTION. The information-flow blame problem is to identify the pos- sible sources of an error in a program. An effective
Derived Types What Are Derived Types?
Collett Jr., Jeffrey L.
Derived Types #12;What Are Derived Types? As usual, a hybrid of two, unrelated concepts C++, Python orientation comes in #12;Simple Derived Types TYPE Wheel INTEGER :: spokes REAL :: diameter, width CHARACTER(LEN=15) :: material END TYPE Wheel That defines a derived type Wheel Using derived types needs a special
Derived Types What Are Derived Types?
Collett Jr., Jeffrey L.
Derived Types #12;What Are Derived Types? As usual, a hybrid of two, unrelated concepts C object orientation comes in This course will only describe the former. #12;Simple Derived Types TYPE That defines a derived type Wheel Using derived types needs a special syntax TYPE(Wheel) :: w1 #12;More
Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site
AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on Delicious RankADVANCEDInstallers/ContractorsPhotovoltaicsStateof Energy TwoEvent at the Pu Facility,Type IV COPV1
Steam-water two-phase flow in large diameter vertical piping at high pressures and temperatures
Hasanein, H.A.; Kawaji, Masahiro [Univ. of Toronto, Ontario (Canada); Chan, A.M.C. [Ontario Hydro Technologies, Toronto, Ontario (Canada); Yoshioka, Yuzuru [Japan Atomic Power Co., Tokyo (Japan)
1996-08-01
No information on steam/water two-phase flow behavior in large diameter pipes (10 inch or larger) at elevated pressures is available in the open literature. However, there are many applications, in the nuclear, chemical and petroleum industries among others where two-phase flows in large diameter pipes at elevated pressures and temperatures are encountered routinely or under accident scenarios. Experimental data on steam-water two-phase flow in a large diameter (20 inch, 50.08 cm I.D.) vertical pipe at elevated pressures and temperatures (2.8 MPa/230 C--6.4 MPa/280 C) have been obtained. Void fraction, two-phase mass flux, phase and velocity distributions as well as pressure drop along the test pipe have been measured using the Ontario Hydro Technologies (OHT) Pump Test Loop. The void fraction distributions were found to be axially symmetric and nearly flat over a wide range of two-phase flow conditions. The two-phase flow regime could be inferred from the dynamic void fluctuations data. For the 280 C tests, the flow was found to be relatively stable with bubbly flow at low average void fractions and churn turbulent or wispy-annular flow at higher void fractions. At 230 C, the flow became rather oscillatory and slugging was suspected at relatively low voids. It has also been found that the average void fractions in the test section can be determined reasonably accurately using the axial pressure drop data.
Fair Internet traffic integration: network flow models and analysis
Kelly, Frank
Fair Internet traffic integration: network flow models and analysis Peter Key, Laurent Massoulié the integration of two types of Internet traffic, elastic file transfers and streaming traffic. Previous studies have concentrated on just one type of traffic, such as the flow level models of Internet congestion
Enciso, Juan; Santistevan, Dean; Hla, Aung K.
2007-10-01
Propeller flow meters are commonly used to measure water flow rate. They can also be used to estimate irrigation water use. This publication explains how to select, install, read and maintain propeller flow meters....
Marcos, Ph.D. Massachusetts Institute of Technology
2011-01-01
Bacteria are ubiquitous and play a critical role in many contexts. Their environment is nearly always dynamic due to the prevalence of fluid flow: creeping flow in soil, highly sheared flow in bodily conduits, and turbulent ...
Yoder, Graydon L.
1980-01-01
Dispersed flow consists of small liquid droplets entrained in a flowing vapor. This flow regime can occur in cryogenic equipment, in steam generators, and during nuclear reactor loss of coolant accidents. A theoretical ...
Modular axial-flux permanent-magnet motor for ship propulsion drives
Caricchi, F.; Crescimbini, F.; Honorati, O.
1999-09-01
Original features such as compactness and lightness make slotless axial-flux permanent-magnet machines (AFPMs) eligible for application in large power motor drives devoted to the direct drive of ship propellers. This paper discusses characteristics of AFPMs designed for application in marine propulsion, and machine performances such as efficiency, weight and torque density are evaluated for a comparison with those of conventional synchronous machines. A newly-conceived modular arrangement of the machine stator winding is proposed and experimental results taken from a small-size machine prototype are finally shown.
High-Efficiency Deflection of High-Energy Protons through Axial Channeling in a Bent Crystal
Scandale, Walter; Vomiero, Alberto; Baricordi, Stefano; Dalpiaz, Pietro; Fiorini, Massimiliano; Guidi, Vincenzo; Mazzolari, Andrea; Della Mea, Gianantonio; Milan, Riccardo; Ambrosi, Giovanni; Bertucci, Bruna; Burger, William J.; Zuccon, Paolo; Cavoto, Gianluca; Luci, Claudio; Santacesaria, Roberta; Valente, Paolo; Vallazza, Erik; Afonin, Alexander G.; Chesnokov, Yury A.
2008-10-17
Beam deflection due to axial channeling in a silicon crystal bent along the <111> axis was observed with 400 GeV/c protons at the CERN Super Proton Synchrotron. The condition for doughnut scattering of protons by the atomic strings of the crystal was attained. Such a condition allowed one to observe a beam deflection of 50 {mu}rad with about 30% efficiency. The contribution of hyperchanneled states of protons to the observed beam deflection was less than 2% according to simulation results.
Axial range of conjugate adaptive optics in two-photon microscopy
Paudel, Hari P; Mertz, Jerome; Bifano, Thomas
2015-01-01
We describe an adaptive optics technique for two-photon microscopy in which the deformable mirror used for aberration compensation is positioned in a plane conjugate to the plane of the aberration. We demonstrate in a proof-of-principle experiment that this technique yields a large field of view advantage in comparison to standard pupil-conjugate adaptive optics. Further, we show that the extended field of view in conjugate AO is maintained over a relatively large axial translation of the deformable mirror with respect to the conjugate plane. We conclude with a discussion of limitations and prospects for the conjugate AO technique in two-photon biological microscopy.
Asymptotic axial symmetry of solutions of parabolic equations in bounded radial domains
Saldana, Alberto
2011-01-01
We consider solutions of some nonlinear parabolic boundary value problems in radial bounded domains whose initial profile satisfy a reflection inequality with respect to a hyperplane containing the origin. We show that, under rather general assumptions, these solutions are asymptotically (in time) foliated Schwarz symmetric, i.e., all elements in the associated omega limit set are axially symmetric with respect to a common axis passing through the origin and nonincreasing in the polar angle from this axis. In this form, the result is new even for equilibria (i.e. solutions of the corresponding elliptic problem) and time periodic solutions.
Mishra, S. K. [Institute for Plasma Research (IPR), Gandhinagar (India)] [Institute for Plasma Research (IPR), Gandhinagar (India); Sharma, A. [Institute of Physics, University of Pecs, Pecs 7624 (Hungary)] [Institute of Physics, University of Pecs, Pecs 7624 (Hungary)
2013-07-15
We investigate the spatiotemporal focusing dynamics of a Gaussian laser pulse in preformed collisionless plasma subjected to an axial nonuniformity in the plasma density. In order to follow up the pulse dynamics, a nonlinear Schrödinger wave equation characterizing the beam spot size in space and time frame has been derived and solved numerically to investigate the propagation characteristics as the pulse advances in the plasma. The effect of inhomogeneity on focusing length and ponderomotive electron heating have been analyzed and illustrated graphically. It is seen that ponderomotive heating is quite sensitive to the inhomogeneity parameters and the energy gain by electrons can be optimized by suitable choice of parameters.
Halden In-Reactor Test to Exhibit PWR Axial Offset Anomaly
P.Bennett, B. Beverskog, R.Suther
2004-12-01
Many PWRs have encountered the axial offset anomaly (AOA) since the early 1990s, and these experiences have been reported widely. AOA is a phenomenon associated with localized boron hideout in corrosion product deposits (crud) on fuel surfaces. Several mitigation approaches have been developed or are underway to either delay the onset of AOA or avoid it entirely. This study describes the first phase of an experimental program designed to investigate whether the use of enriched boric acid (EBA) in the reactor coolant can mitigate AOA.
Axial force imparted by a conical radiofrequency magneto-plasma thruster
Charles, C.; Takahashi, K.; Boswell, R. W. [Space Plasma, Power and Propulsion Laboratory, Research School of Physics and Engineering, Australian National University, ACT 0200 (Australia)
2012-03-12
Direct thrust measurements of a low pressure ({approx}0.133 Pa) conical radiofrequency (rf at 13.56 MHz) argon plasma source show a total axial force of about 5 mN for an effective rf power of 650 W and a maximum magnetic field of 0.018 T, of which a measured value of 2.5 mN is imparted by the magnetic nozzle. A simplified model of thrust including contributions from the electron pressure and from the magnetic field pressure is developed. The magnetic nozzle is modelled as a ''physical'' nozzle of increasing cross-sectional area.
Flow instabilities of magnetic flux tubes II. Longitudinal flow
V. Holzwarth; D. Schmitt; M. Schuessler
2007-04-27
Flow-induced instabilities are relevant for the storage and dynamics of magnetic fields in stellar convection zones and possibly also in other astrophysical contexts. We continue the study started in the first paper of this series by considering the stability properties of longitudinal flows along magnetic flux tubes. A linear stability analysis was carried out to determine criteria for the onset of instability in the framework of the approximation of thin magnetic flux tubes. In the non-dissipative case, we find Kelvin-Helmholtz instability for flow velocities exceeding a critical speed that depends on the Alfv{\\'e}n speed and on the ratio of the internal and external densities. Inclusion of a friction term proportional to the relative transverse velocity leads to a friction-driven instability connected with backward (or negative energy) waves. We discuss the physical nature of this instability. In the case of a stratified external medium, the Kelvin-Helmholtz instability and the friction-driven instability can set in for flow speeds significantly lower than the Alfv{\\'e}n speed. Dissipative effects can excite flow-driven instability below the thresholds for the Kelvin-Helmholtz and the undulatory (Parker-type) instabilities. This may be important for magnetic flux storage in stellar convection zones and for the stability of astrophysical jets.
FLOW-THROUGH POROUS ELECTRODES
Trainham, III, James Arthur
2011-01-01
configurations for flow redox battery applications: (i) theporous electrodes A flow-redox battery using flow-by poroustrue in battery applications, Flow..through porous
A New Algorithm for Multicommodity Flow
Dhananjay P. Mehendale
2010-01-13
We propose a new algorithm to obtain max flow for the multicommodity flow. This algorithm utilizes the max-flow min-cut theorem and the well known labeling algorithm due to Ford and Fulkerson [1]. We proceed as follows: We select one source/sink pair among the n distinguished source/sink pairs at a time and treat the given multicommodity network as a single commodity network for such chosen source/sink pair. Then applying standard labeling algorithm, separately for each sink/source pair, the feasible flow which is max flow and the corresponding minimum cut corresponding to each source/sink pair is obtained. A record is made of these cuts and the paths flowing through the edges of these cuts. This record is then utilized to develop our algorithm to obtain max flow for multicommodity flow. In this paper we have pinpointed the difficulty behind not getting a max flow min cut type theorem for multicommodity flow and found out a remedy.
Multiphase flow calculation software
Fincke, James R. (Idaho Falls, ID)
2003-04-15
Multiphase flow calculation software and computer-readable media carrying computer executable instructions for calculating liquid and gas phase mass flow rates of high void fraction multiphase flows. The multiphase flow calculation software employs various given, or experimentally determined, parameters in conjunction with a plurality of pressure differentials of a multiphase flow, preferably supplied by a differential pressure flowmeter or the like, to determine liquid and gas phase mass flow rates of the high void fraction multiphase flows. Embodiments of the multiphase flow calculation software are suitable for use in a variety of applications, including real-time management and control of an object system.
High energy density Z-pinch plasmas using flow stabilization
Shumlak, U. Golingo, R. P. Nelson, B. A. Bowers, C. A. Doty, S. A. Forbes, E. G. Hughes, M. C. Kim, B. Knecht, S. D. Lambert, K. K. Lowrie, W. Ross, M. P. Weed, J. R.
2014-12-15
The ZaP Flow Z-Pinch research project[1] at the University of Washington investigates the effect of sheared flows on MHD instabilities. Axially flowing Z-pinch plasmas are produced that are 100 cm long with a 1 cm radius. The plasma remains quiescent for many radial Alfvén times and axial flow times. The quiescent periods are characterized by low magnetic mode activity measured at several locations along the plasma column and by stationary visible plasma emission. Plasma evolution is modeled with high-resolution simulation codes – Mach2, WARPX, NIMROD, and HiFi. Plasma flow profiles are experimentally measured with a multi-chord ion Doppler spectrometer. A sheared flow profile is observed to be coincident with the quiescent period, and is consistent with classical plasma viscosity. Equilibrium is determined by diagnostic measurements: interferometry for density; spectroscopy for ion temperature, plasma flow, and density[2]; Thomson scattering for electron temperature; Zeeman splitting for internal magnetic field measurements[3]; and fast framing photography for global structure. Wall stabilization has been investigated computationally and experimentally by removing 70% of the surrounding conducting wall to demonstrate no change in stability behavior.[4] Experimental evidence suggests that the plasma lifetime is only limited by plasma supply and current waveform. The flow Z-pinch concept provides an approach to achieve high energy density plasmas,[5] which are large, easy to diagnose, and persist for extended durations. A new experiment, ZaP-HD, has been built to investigate this approach by separating the flow Z-pinch formation from the radial compression using a triaxial-electrode configuration. This innovation allows more detailed investigations of the sheared flow stabilizing effect, and it allows compression to much higher densities than previously achieved on ZaP by reducing the linear density and increasing the pinch current. Experimental results and scaling analyses will be presented. In addition to studying fundamental plasma science and high energy density physics, the ZaP and ZaP-HD experiments can be applied to laboratory astrophysics.
Flow Distances on Open Flow Networks
Guo, Liangzhu; Shi, Peiteng; Wang, Jun; Huang, Xiaohan; Zhang, Jiang
2015-01-01
Open flow network is a weighted directed graph with a source and a sink, depicting flux distributions on networks in the steady state of an open flow system. Energetic food webs, economic input-output networks, and international trade networks, are open flow network models of energy flows between species, money or value flows between industrial sectors, and goods flows between countries, respectively. Flow distances (first-passage or total) between any given two nodes $i$ and $j$ are defined as the average number of transition steps of a random walker along the network from $i$ to $j$ under some conditions. They apparently deviate from the conventional random walk distance on a closed directed graph because they consider the openness of the flow network. Flow distances are explicitly expressed by underlying Markov matrix of a flow system in this paper. With this novel theoretical conception, we can visualize open flow networks, calculating centrality of each node, and clustering nodes into groups. We apply fl...
Broken axial symmetry as essential feature to predict radiative capture in heavy nuclei
Grosse, Eckart; Massarczyk, Ralph
2014-01-01
Cross sections for neutron capture in the range of unresolved resonances are predicted for more than 140 spin-0 target nuclei with A > 50. Allowing the breaking of spherical and axial symmetry in nearly all these nuclei a combined parameterization for both, level density and photon strength is obtained which employs a surprisingly small number of parameters only. The strength functions used are based on a global fit to IVGDR shapes by the sum of three Lorentzians. They are based on theoretical predictions for the A-dependence of pole energies and spreading widths and add up to the TRK sum rule. For the small spins reached by capture resonance spacings are well described by a level density parameter close to the nuclear matter value; a significant collective enhancement is apparent due to the deviation from axial symmetry. Reliable predictions for compound nuclear reactions also outside the valley of stability (as important for nuclear astrophysics and for the transmutation of nuclear waste) are expected to re...
Broken axial symmetry as essential feature to predict radiative capture in heavy nuclei
Eckart Grosse; Arnd R. Junghans; Ralph Massarczyk
2015-01-14
Cross sections for neutron capture in the range of unresolved resonances are predicted for more than 140 spin-0 target nuclei with A > 50. Allowing the breaking of spherical and axial symmetry in nearly all these nuclei a combined parameterization for both, level density and photon strength is obtained which employs a surprisingly small number of parameters only. The strength functions used are based on a global fit to IVGDR shapes by the sum of three Lorentzians. They are based on theoretical predictions for the A-dependence of pole energies and spreading widths and add up to the TRK sum rule. For the small spins reached by capture resonance spacings are well described by a level density parameter close to the nuclear matter value; a significant collective enhancement is apparent due to the deviation from axial symmetry. Reliable predictions for compound nuclear reactions also outside the valley of stability (as important for nuclear astrophysics and for the transmutation of nuclear waste) are expected to result from the global parameterization presented.
Fracture analysis of axially cracked pressure tube of pressurized heavy water reactor
Krishnan, S.; Bhasin, V.; Mahajan, S.C. [Bhabha Atomic Research Centre, Bombay (India)] [and others
1997-04-01
Three Dimensional (313) finite element elastic plastic fracture analysis was done for through wall axially cracked thin pressure tubes of 220 MWe Indian Pressurized Heavy Water Reactor. The analysis was done for Zr-2 and Zr-2.5Nb pressure tubes operating at 300{degrees}C and subjected to 9.5 Mpa internal pressure. Critical crack length was determined based on tearing instability concept. The analysis included the effect of crack face pressure due to the leaking fluid from tube. This effect was found to be significant for pressure tubes. The available formulae for calculating J (for axially cracked tubes) do not take into account the effect of crack face pressure. 3D finite element analysis also gives insight into variation of J across the thickness of pressure tube. It was observed that J is highest at the mid-surface of tube. The results have been presented in the form of across the thickness average J value and a peak factor on J. Peak factor on J is ratio of J at mid surface to average J value. Crack opening area for different cracked lengths was calculated from finite element results. The fracture assessment of pressure tubes was also done using Central Electricity Generating Board R-6 method. Ductile tearing was considered.
A picoliter `fountain-pen' using co-axial dual pipettes Ofer Feinerman *, Elisha Moses
Moses, Elisha
, controlled drug infusion is presented. Two concentric pipettes can be manipulated separately and pressurized resolution of the infusion is highly controllable, and oscillatory flow can be generated. Three
Portable wastewater flow meter
Hunter, Robert M. (320 S. Wilson Ave., Bozeman, MT 59715)
1999-02-02
A portable wastewater flow meter particularly adapted for temporary use at a single location in measuring the rate of liquid flow in a circular entrance conduit of a sewer manhole both under free flow and submerged, open channel conditions and under fill pipe, surcharged conditions, comprising an apparatus having a cylindrical external surface and an inner surface that constricts the flow through the apparatus in such a manner that a relationship exists between (1) the difference between the static pressure head of liquid flowing through the entrance of the apparatus and the static pressure head of liquid flowing through the constriction, and (2) the rate of liquid flow through the apparatus.
Portable wastewater flow meter
Hunter, Robert M. (320 S. Wilson Ave., Bozeman, MT 59715)
1990-01-01
A portable wastewater flow meter particularly adapted for temporary use at a single location in measuring the rate of liquid flow in a circular entrance conduit of a sewer manhole both under free flow and submerged, open channel conditions and under full pipe, surcharged conditions, comprising an apparatus having a cylindrical external surface and an inner surface that constricts the flow through the apparatus in such a manner that a relationship exists between (1) the difference between the static pressure head of liquid flowing through the entrance of the apparatus and the static pressure head of liquid flowing through the constriction, and (2) the rate of liquid flow through the apparatus.
Hakoyama, Tomoyuki [Department of Mechanical Systems Engineering, Graduate school of Engineering, Tokyo University of Agriculture and Technology, 2-24-16, Nakacho, Koganei-shi, Tokyo, 184-8588 (Japan); Kuwabara, Toshihiko [Division of Advanced Mechanical Systems Engineering, Institute of Engineering, Tokyo University of Agriculture and Technology, 2-24-16, Nakacho, Koganei-shi, Tokyo, 184-8588 (Japan)
2013-12-16
A servo-controlled tension-internal pressure testing machine with an optical 3D deformation analysis system (ARAMIS) was used to measure the multi-axial plastic deformation behavior of a high-strength steel sheet for a range of strain from initial yield to fracture. The testing machine is capable of applying arbitrary principal stress or strain paths to a tubular specimen using an electrical, closed-loop servo-control system for axial force and internal pressure. Tubular specimens with an inner diameter of 44.6 mm were fabricated from a high-strength steel sheet with a tensile strength of 590 MPa and a thickness of 1.2 mm by roller bending and laser welding. Several linear and non-linear stress paths in the first quadrant of the stress space were applied to the tubular specimens in order to measure the forming limit curve (FLC) and forming limit stress curve (FLSC) of the as-received test material, in addition to the contours of plastic work and the directions of plastic strain rates. The contours of plastic work and the directions of plastic strain rates measured for the linear stress path experiments were compared with those calculated using selected yield functions in order to identify the most appropriate yield function for the test material. Moreover, a Marciniak-Kuczy?ski type (M-K) forming limit analysis was performed using the most appropriate yield function. The calculated and measured FLC and FLSC were compared in order to validate the M-K approach. The path-dependence of the FLC and FLSC was also investigated.
Energy of eigen-modes in magnetohydrodynamic flows of ideal fluids
I. V. Khalzov; A. I. Smolyakov; V. I. Ilgisonis
2007-12-11
Analytical expression for energy of eigen-modes in magnetohydrodynamic flows of ideal fluids is obtained. It is shown that the energy of unstable modes is zero, while the energy of stable oscillatory modes (waves) can assume both positive and negative values. Negative energy waves always correspond to non-symmetric eigen-modes -- modes that have a component of wave-vector along the equilibrium velocity. These results suggest that all non-symmetric instabilities in ideal MHD systems with flows are associated with coupling of positive and negative energy waves. As an example the energy of eigen-modes is calculated for incompressible conducting fluid rotating in axial magnetic field.
STUDY TYPES What is a "Study Type"?
Dorf, Martin E.
#12;STUDY TYPES What is a "Study Type"? A Study Type is a defined business process. Study Types work together to streamline workflow, track data & keep users informed. There are 2 Study Types in eCOMS: COMS and IACUC. The COMS Study: The COMS Study is an online form that a Principal Investigator fills
Relaxation of axially confined 400 GeV/c protons to planar channeling in a bent crystal
L. Bandiera; A. Mazzolari; E. Bagli; G. Germogli; V. Guidi; A. Sytov; I. V. Kirillin; N. F. Shul'ga; A. Berra; D. Lietti; M. Prest; D. De Salvador; E. Vallazza
2015-11-10
An investigation on the mechanism of relaxation of axially confined 400 GeV/c protons to planar channeling in a bent crystal was carried out at the extracted line H8 from CERN Super Proton Synchrotron. The experimental results were critically compared to computer simulations, showing a good agreement. We firmly individuated a necessary condition for the exploitation of axial confinement or its relaxation for particle beam manipulation in high-energy accelerators. We demonstrated that with a short bent crystal, aligned with one of its main axis to the beam direction, it is possible to realize either a total beam steerer or a beam splitter with adjustable intensity. In particular, in the latter case, a complete relaxation from axial confinement to planar channeling takes place, resulting in beam splitting into the two strongest skew planar channels.
Relaxation of axially confined 400 GeV/c protons to planar channeling in a bent crystal
Bandiera, L; Bagli, E; Germogli, G; Guidi, V; Sytov, A; Kirillin, I V; Shul'ga, N F; Berra, A; Lietti, D; Prest, M; De Salvador, D; Vallazza, E
2015-01-01
An investigation on the mechanism of relaxation of axially confined 400 GeV/c protons to planar channeling in a bent crystal was carried out at the extracted line H8 from CERN Super Proton Synchrotron. The experimental results were critically compared to computer simulations, showing a good agreement. We firmly individuated a necessary condition for the exploitation of axial confinement or its relaxation for particle beam manipulation in high-energy accelerators. We demonstrated that with a short bent crystal, aligned with one of its main axis to the beam direction, it is possible to realize either a total beam steerer or a beam splitter with adjustable intensity. In particular, in the latter case, a complete relaxation from axial confinement to planar channeling takes place, resulting in beam splitting into the two strongest skew planar channels.
Alton, Gerald D. (Kingston, TN)
1996-01-01
An electron cyclotron resonance (ECR) ion source includes a primary mirror coil disposed coaxially around a vacuum vessel in which a plasma is induced and introducing a solenoidal ECR-producing field throughout the length of the vacuum vessel. Radial plasma confinement is provided by a multi-cusp, multi-polar permanent magnet array disposed azimuthally around the vessel and within the primary mirror coil. Axial confinement is provided either by multi-cusp permanent magnets at the opposite axial ends of the vessel, or by secondary mirror coils disposed on opposite sides of the primary coil.
Nucleon and Delta axial-vector couplings in 1/N{sub c}-Baryon Chiral Perturbation Theory
Goity, Jose Luis [JLAB; Calle Cordon, Alvaro [JLAB
2013-08-01
In this contribution, baryon axial-vector couplings are studied in the framework of the combined 1/N{sub c} and chiral expansions. This framework is implemented on the basis of the emergent spin-flavor symmetry in baryons at large N{sub c} and HBChPT, and linking both expansions ({xi}-expansion), where 1/N{sub c} is taken to be a quantity order p. The study is carried out including one-loop contributions, which corresponds to order xi to the third for baryon masses and order {xi} square for the axial couplings.
Fluid mechanics experiments in oscillatory flow. Volume 1
Seume, J.; Friedman, G.; Simon, T.W.
1992-03-01
Results of a fluid mechanics measurement program is oscillating flow within a circular duct are present. The program began with a survey of transition behavior over a range of oscillation frequency and magnitude and continued with a detailed study at a single operating point. Such measurements were made in support of Stirling engine development. Values of three dimensionless parameters, Re{sub max}, Re{sub W}, and A{sub R}, embody the velocity amplitude, frequency of oscillation and mean fluid displacement of the cycle, respectively. Measurements were first made over a range of these parameters which included operating points of all Stirling engines. Next, a case was studied with values of these parameters that are representative of the heat exchanger tubes in the heater section of NASA`s Stirling cycle Space Power Research Engine (SPRE). Measurements were taken of the axial and radical components of ensemble-averaged velocity and rms-velocity fluctuation and the dominant Reynolds shear stress, at various radial positions for each of four axial stations. In each run, transition from laminar to turbulent flow, and in reverse, were identified and sufficient data was gathered to propose the transition mechanism. Models of laminar and turbulent boundary layers were used to process the data into wall coordinates and to evaluate skin friction coefficients. Such data aids in validating computational models and is useful in comparing oscillatory flow characteristics to those of fully-developed steady flow. Data were taken with a contoured entry to each end of the test section and with flush square inlets so that the effects of test section inlet geometry on transition and turbulence are documented. The following is presented in two-volumes. Volume I contains the text of the report including figures and supporting appendices. Volume II contains data reduction program listings and tabulated data (including its graphical presentation).
Constraints on Axial Two-Body Currents from Solar Neutrino Data
A. B. Balantekin; H. Yuksel
2003-07-31
We briefly review recent calculations of neutrino deuteron cross sections within the effective field theory and traditional potential model approaches. We summarize recent efforts to determine the counter term describing axial two-body currents, L_{1A}, in the effective field theory approach. We determine the counter term directly from the solar neutrino data and find several, slightly different, ranges of L_{1A} under different sets of assumptions. Our most conservative fit value with the largest uncertainty is L_{1A} = 4.5 +18/-12 fm^3. We show that the contribution of the uncertainty of L_{1A} to the analysis and interpretation of the solar neutrino data measured at the Sudbury Neutrino Observatory is significantly less than the uncertainty coming from the lack of having a better knowledge of \\theta_{13}.
Mavko, B.; Cizelj, L. (Jozef Stefan Inst., Reactor Engineering Div., P.O. Box 100, 61111 Ljubljana, Slovenia (YU))
1992-05-01
In this paper a model for estimating the failure probability of axially cracked steam generator tubes is proposed. The model compares observed crack length distribution with critical crack length distribution by means of probabilistic fracture mechanics. The observed crack length is influenced by measured data, measurement reliability, sizing accuracy, and predicted crack growth rate. The critical crack length is defined by a deterministic mechanical model. All cracks are conservatively assumed to extend through the tube wall. The effect of the plugging limit is studied along with the number of cracked tubes to perform risk-based lifetime optimization of steam generators. A numerical example presented considers hypothetical accidental operating conditions during a feedwater line break.
Magneto-hydrodynamics simulation study of deflagration mode in co-axial plasma accelerators
Sitaraman, Hariswaran; Raja, Laxminarayan L.
2014-01-15
Experimental studies by Poehlmann et al. [Phys. Plasmas 17(12), 123508 (2010)] on a coaxial electrode magnetohydrodynamic (MHD) plasma accelerator have revealed two modes of operation. A deflagration or stationary mode is observed for lower power settings, while higher input power leads to a detonation or snowplow mode. A numerical modeling study of a coaxial plasma accelerator using the non-ideal MHD equations is presented. The effect of plasma conductivity on the axial distribution of radial current is studied and found to agree well with experiments. Lower conductivities lead to the formation of a high current density, stationary region close to the inlet/breech, which is a characteristic of the deflagration mode, while a propagating current sheet like feature is observed at higher conductivities, similar to the detonation mode. Results confirm that plasma resistivity, which determines magnetic field diffusion effects, is fundamentally responsible for the two modes.
Long, C.A.; Morse, A.P.; Tucker, P.G.
1997-01-01
This paper makes comparisons between CFD computations and experimental measurements of heat transfer for the axial throughflow of cooling air in a high-pressure compressor spool rig and a plane cavity rig. The heat transfer measurements are produced using fluxmeters and by the conduction solution method from surface temperature measurements. Numerical predictions are made by solving the Navier-Stokes equations in a full three-dimensional, time-dependent form using the finite-volume method. Convergence is accelerated using a multigrid algorithm and turbulence modeled using a simple mixing length formulation. Notwithstanding systematic differences between the measurements and the computations, the level of agreement can be regarded as promising in view of the acknowledged uncertainties in the experimental data, the limitations of the turbulence model and, perhaps more importantly, the modest grid densities used for the computations.
Stanislav S. Zub; Sergiy I. Zub
2015-02-13
The symmetric top is a special case of the general top, and canonical Poisson structure on $T^*SE(3)$ is the common method of its description. This structure is invariant under the right action of $SO(3)$, but the Hamiltonian of the symmetric top is invariant only under the right action of subgroup $S^1$ that corresponds to the rotation around the symmetry axis of the symmetric top. So, its Poisson structure was obtained as the reduction $T^*SE(3)/S^1$. Next we propose the Hamiltonian that describes the wide class of the interaction models of symmetric top and axially-symmetric external field. The stability of the levitating Orbitron in relative equilibrium was proved.
Measurements of the Ion Species of Cathodic Arc Plasma in an Axial Magnetic Field
Oks, Efim; Anders, Andre
2010-10-19
Metal and gas ion species and their charge state distributions were measured for pulsed copper cathodic arcs in argon background gas in the presence of an axial magnetic field. It was found that changing the cathode position relative to anode and ion extraction system as well as increasing the gas pressure did not much affect the arc burning voltage and the related power dissipation. However, the burning voltage and power dissipation greatly increased as the magnetic field strength was increased. The fraction of metal ions and the mean ion charge state were reduced as the discharge length was increased. The observations can be explained by the combination of charge exchange collisions and electron impact ionization. They confirm that previously published data on characteristic material-dependent charge state distributions (e.g., Anders and Yushkov, J. Appl. Phys., Vol. 91, pp. 4824-4832, 2002) are not universal but valid for high vacuum conditions and the specifics of the applied magnetic fields.
Axial quasi-normal modes of Einstein-Gauss-Bonnet-dilaton neutron stars
Blázquez-Salcedo, Jose Luis; Kunz, Jutta; Mojica, Sindy; Navarro-Lérida, Francisco
2015-01-01
We investigate axial quasi-normal modes of realistic neutron stars in Einstein-Gauss-Bonnet-dilaton gravity. We consider 8 realistic equations of state containing nuclear, hyperonic, and hybrid matter. We focus on the fundamental curvature mode and compare the results with those of pure Einstein theory. We observe that the frequency of the modes is increased by the presence of the Gauss-Bonnet-dilaton, while the impact on the damping time is typically smaller. Interestingly, we obtain that universal relations valid in pure Einstein theory still hold for Einstein-Gauss-Bonnet-dilaton gravity, and we propose a method to use these phenomenological relations to constrain the value of the Gauss-Bonnet coupling.
Despax, B.; Makasheva, K. [Universite de Toulouse, UPS, INPT, LAPLACE (Laboratoire Plasma et Conversion d'Energie), 118 route de Narbonne, F-31062 Toulouse 09 (France); CNRS, LAPLACE, F-31062 Toulouse cedex 09 (France); Caquineau, H. [Universite de Toulouse, UPS, INPT, LAPLACE (Laboratoire Plasma et Conversion d'Energie), 118 route de Narbonne, F-31062 Toulouse 09 (France)
2012-11-01
A new approach of periodic production of dusty plasma consisting of pulsed injection of hexamethyldisiloxane (HMDSO) in argon axially asymmetric radiofrequency (RF) discharge was investigated in this work. The range of plasma operating conditions in which this dusty plasma can exist was closely examined. The obtained results clearly show that a net periodicity in the formation/disappearance of dust particles in the plasma can be maintained on a very large scale of discharge duration. The significance of discharge axial asymmetry to the dust particles behaviour in the plasma is revealed by the development of an asymmetric in shape void shifted towards the powered RF electrode. The key role of the reactive gas and its pulsed injection on each stage of the oscillating process of formation/disappearance of dust particles is disclosed by optical and electrical measurements. It is shown that the period of dusty plasma formation/disappearance is inversely related to the HMDSO injection time. Moreover, the impact of time injection over short period (5 s) is examined. It indicates the conflicting role played by the HMDSO on the reduction of dusty plasma during the reactive gas injection and the reappearance of particles in the plasma during the time off. The electronegative behavior of the plasma in the presence of negatively charged particles seems to explain the energetic modifications in the discharge. A frequency analysis of the floating potential reveals all these cyclic processes. Particularly, in the 10-200 Hz frequency range, the presence and the evolution of dust particles in the plasma over one generation can be observed.
Mock, Raymond Cecil; Nash, Thomas J.; Sanford, Thomas W. L.
2007-03-01
We present designs for dynamic hohlraum z-pinch loads on the 28 MA, 140 ns driver ZR. The scaling of axially radiated power with current in dynamic hohlraums is reviewed. With adequate stability on ZR this scaling indicates that 30 TW of axially radiated power should be possible. The performance of the dynamic hohlraum load on the 20 MA, 100 ns driver Z is extensively reviewed. The baseline z-pinch load on Z is a nested tungsten wire array imploding onto on-axis foam. Data from a variety of x-ray diagnostics fielded on Z are presented. These diagnostics include x-ray diodes, bolometers, fast x-ray imaging cameras, and crystal spectrometers. Analysis of these data indicates that the peak dynamic radiation temperature on Z is between 250 and 300 eV from a diameter less than 1 mm. Radiation from the dynamic hohlraum itself or from a radiatively driven pellet within the dynamic hohlraum has been used to probe a variety of matter associated with the dynamic hohlraum: the tungsten z-pinch itself, tungsten sliding across the end-on apertures, a titanium foil over the end aperture, and a silicon aerogel end cap. Data showing the existence of asymmetry in radiation emanating from the two ends of the dynamic hohlraum is presented, along with data showing load configurations that mitigate this asymmetry. 1D simulations of the dynamic hohlraum implosion are presented and compared to experimental data. The simulations provide insight into the dynamic hohlraum behavior but are not necessarily a reliable design tool because of the inherently 3D behavior of the imploding nested tungsten wire arrays.
Space charge field in a FEL with axially symmetric electron beam
Goncharov, I.A.; Belyavskiy, E.D.
1995-12-31
Nonlinear two-dimensional theory of the space charge of an axially symmetric electron beam propagating in combined right-hand polarized wiggler and uniform axial guide fields in a presence of high-frequency electromagnetic wave is presented. The well-known TE{sub 01} mode in a cylindrical waveguide for the model of radiation fields and paraxial approximation for the wiggler field are used. Space charge field components are written in the Lagrange coordinates by the twice averaged Green`s functions of two equally charged infinitely thin discs. For that {open_quotes}compensating charges{close_quotes} method is applied in which an electron ring model is substituted by one with two different radii and signs discs. On this approach the initial Green`s functions peculiarities are eliminated and all calculations are considerably simplified. Coefficients of a twice averaged Green`s function expansion into a Fourier series are obtained by use of corresponding expansion coefficients of longitudinal Green`s functions of equal radii discs and identical rings known from the one-dimensional theory of super HF devices taking into account electron bunches periodicity. This approach permit the space charge field components for an arbitrary stratified stream to be expressed in a simple and strict enough form. The expressions obtained can be employed in a nonlinear two-dimensional FEL theory in order to investigate beam dynamical defocusing and electrons failing on the waveguide walls in the high gain regime. This is especially important for FEL operation in mm and submm.
Mechanical annealing in the flow of supercooled metallic liquid
Zhang, Meng [State Key Lab of Materials Processing and Die and Mold Technology, School of Materials Science and Engineering, Huazhong University of Science and Technology, Wuhan 430074 (China); State Key Laboratory of Nonlinear Mechanics, Institute of Mechanics, Chinese Academy of Sciences, Beijing 100190 (China); Dai, Lan Hong [State Key Laboratory of Nonlinear Mechanics, Institute of Mechanics, Chinese Academy of Sciences, Beijing 100190 (China); Liu, Lin, E-mail: lliu2000@mail.hust.edu.cn [State Key Lab of Materials Processing and Die and Mold Technology, School of Materials Science and Engineering, Huazhong University of Science and Technology, Wuhan 430074 (China)
2014-08-07
Flow induced structural evolution in a supercooled metallic liquid Vit106a (Zr{sub 58.5}Cu{sub 15.6}Al{sub 10.3}Ni{sub 12.8}Nb{sub 2.8}, at.?%) was investigated via uni-axial compression combined with differential scanning calorimeter (DSC). Compression tests at strain rates covering the transition from Newtonian flow to non-Newtonian flow and at the same strain rate 2?×?10{sup ?1} s{sup ?1} to different strains were performed at the end of glass transition (T{sub g-end}?=?703?K). The relaxation enthalpies measured by DSC indicate that the samples underwent non-Newtonian flow contain more free volume than the thermally annealed sample (703?K, 4?min), while the samples underwent Newtonian flow contain less, namely, the free volume of supercooled metallic liquids increases in non-Newtonian flow, while decreases in Newtonian flow. The oscillated variation of the relaxation enthalpies of the samples deformed at the same strain rate 2?×?10{sup ?1} s{sup ?1} to different strains confirms that the decrease of free volume was caused by flow stress, i.e., “mechanical annealing.” Micro-hardness tests were also performed to show a similar structural evolution tendency. Based on the obtained results, the stress-temperature scaling in the glass transition of metallic glasses are supported experimentally, as stress plays a role similar to temperature in the creation and annihilation of free volume. In addition, a widening perspective angle on the glass transition of metallic glasses by exploring the 3-dimensional stress-temperature-enthalpy phase diagram is presented. The implications of the observed mechanical annealing effect on the amorphous structure and the work-hardening mechanism of metallic glasses are elucidated based on atomic level stress model.
Flow Field Flow Fractionation Method Development for Applied Bioanalysis
Schachermeyer, Samantha Lynn
2013-01-01
E. ; Caldwell, K. , Field-Flow Fractionation Handbook. JohnJ. P. , Sedimentation field-flow-fractionation: emergence ofby sedimentation field-flow fractionation. Am. Lab. (
Pohle, H.
1985-01-15
In the framework of inverse scattering theory we apply Neugebauer's dressing method to the Bogomolny equation of spontaneously broken SU(N) gauge theory in the massless limit. We use this procedure to construct a new class of (N+3)-parameter solutions describing axially symmetric SU(N) monopoles.
Measurement of velocity deficit at the downstream of a 1:10 axial hydrokinetic turbine B. Gunawan1
Siefert, Chris
plane from upstream to downstream of the turbine at x/D = -10, -5, -3, -2, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10Measurement of velocity deficit at the downstream of a 1:10 axial hydrokinetic turbine model B, Minneapolis, MN 55414. ABSTRACT Wake recovery constrains the downstream spacing and density of turbines
Paperno, Eugene
Shielding Factors of Open-EndedCylindrical Shields Eugene Paperno Dept. of Applied Science for Electronics and Materials, Kyushu University, 6-1 Kasuga-koen, Kasuga-shi,Fukuoka 816-8580.Japan Abstract-Axial shielding factors of single and double- shell open-ended cylindrical magnetic shields are calculated numerically
Identification of spin wave modes in yttrium iron garnet strongly coupled to a co-axial cavity.
Lambert, N. J.; Haigh, J. A.; Ferguson, A. J.
2015-02-05
AIP/123-QED Identification of spin wave modes in yttrium iron garnet strongly coupled to a co-axial cavity. N. J. Lambert,1 J. A. Haigh,2 and A. J. Ferguson1 1)Microelectronics Group, Cavendish Laboratory, University of Cambridge, Cambridge, CB3 0HE...
Calculation of the heavy-hadron axial couplings g1, g2, and g3 using lattice QCD
Will Detmold, David Lin, Stefan Meinel
2012-06-01
In a recent paper [arXiv:1109.2480] we have reported on a lattice QCD calculation of the heavy-hadron axial couplings g{sub 1}, g{sub 2}, and g{sub 3}. These quantities are low-energy constants of heavy-hadron chiral perturbation theory (HH{chi}PT) and are related to the B*B{pi}, {Sigma}{sub b}*{Sigma}{sub b}{pi}, and {Sigma}{sub b}{sup (*)}{Lambda}{sub b}{pi} couplings. In the following, we discuss important details of the calculation and give further results. To determine the axial couplings, we explicitly match the matrix elements of the axial current in QCD with the corresponding matrix elements in HH{chi}PT. We construct the ratios of correlation functions used to calculate the matrix elements in lattice QCD, and study the contributions from excited states. We present the complete numerical results and discuss the data analysis in depth. In particular, we demonstrate the convergence of SU(4|2) HH{chi}PT for the axial current matrix elements at pion masses up to about 400 MeV and show the impact of the nonanalytic loop contributions. Finally, we present additional predictions for strong and radiative decay widths of charm and bottom baryons.
Lin, Weikang; Li, Bao-An; Xu, Jun; Ko, Che Ming; Wen, De Hua.
2011-01-01
the energy release from a neutron star owing to the hadron-quark phase transition. Moreover, the frequency and damping time of the first axial w mode of gravitational waves are studied for both hyperonic and hybrid stars. We find that the energy release...
Ultrasonic flow metering system
Gomm, Tyler J. (Meridian, ID); Kraft, Nancy C. (Idaho Falls, ID); Mauseth, Jason A. (Pocatello, ID); Phelps, Larry D. (Pocatello, ID); Taylor, Steven C. (Idaho Falls, ID)
2002-01-01
A system for determining the density, flow velocity, and mass flow of a fluid comprising at least one sing-around circuit that determines the velocity of a signal in the fluid and that is correlatable to a database for the fluid. A system for determining flow velocity uses two of the inventive circuits with directional transmitters and receivers, one of which is set at an angle to the direction of flow that is different from the others.
Effect of asymmetric axial strain on the behavior of the juncture vortex system
Trosper, Jeffrey Randall
1994-01-01
plexiglass plate. For various airfoil angles of attack, the flow in the juncture was visualized with hydrogen bubbles and with fluorescein dye and the data was recorded on videotape and analyzed quantitatively using a video-based motion analysis system...
FLOW-THROUGH POROUS ELECTRODES
Trainham, III, James Arthur
2011-01-01
Wilhelm. HBoundary conditions of a flow reactor. 1i Chemicala Packed-Bed Electrochemical Flow Reactor." Journal ofRichard, and Brian Gracon. "Flow-Through Porous Electrodes."
Redox Flow Batteries, a Review
Weber, Adam Z.
2013-01-01
Ltd." . Http://Plurionsystems.Com/Tech_Flow_Advantages.Html.plurionsystems.com/tech_flow_advantages.html [71] P. Leung,High Energy Density Redox Flow Device," ed: WO Patent
Restricting information flow in security APIs via typing
Keighren, Gavin
2014-06-27
Security APIs are designed to enable the storage and processing of confidential data without that data becoming known to individuals who are not permitted to obtain it, and are central to the operation of Automated Teller ...
Development of large flow-type proportional counters
Torline, Norbert Kevin
1967-01-01
. REFERENCES' ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ 22 ~ 37 4o ~ 0 ~ 45 LIST OF FIGUBES Figure Page Schematic diagram of a magnetic momentum spectrometer. Time-exposure photograph of ptnportio?al counter pulses disp' eyed on multiple traces of a fast... oscilloscope. 13 Time-exposure of Geiger counter pulses displayed on multiple traces of' a fast oscilloscope. 4 Exploded view of the end of a proportional counter. 16 BI ock diagram of the coincidence circuitry i or ef ficiency measurements. 19 Phy...
University of Technology, Sydney
Assignment Types UTS LIBRARY February 2013 Academic Writing Guide Part 2 Assignment Types: This section outlines the basic types of written assignments, providing structural elements and examples. #12;2 II. Assignment Types 1. Essay Writing
Hoffman, E.L.; Ammerman, D.J.
1995-04-01
A series of tests investigating dynamic pulse buckling of a cylindrical shell under axial impact is compared to several 2D and 3D finite element simulations of the event. The purpose of the work is to investigate the performance of various analysis codes and element types on a problem which is applicable to radioactive material transport packages, and ultimately to develop a benchmark problem to qualify finite element analysis codes for the transport package design industry. Four axial impact tests were performed on 4 in-diameter, 8 in-long, 304 L stainless steel cylinders with a 3/16 in wall thickness. The cylinders were struck by a 597 lb mass with an impact velocity ranging from 42.2 to 45.1 ft/sec. During the impact event, a buckle formed at each end of the cylinder, and one of the two buckles became unstable and collapsed. The instability occurred at the top of the cylinder in three tests and at the bottom in one test. Numerical simulations of the test were performed using the following codes and element types: PRONTO2D with axisymmetric four-node quadrilaterals; PRONTO3D with both four-node shells and eight-node hexahedrons; and ABAQUS/Explicit with axisymmetric two-node shells and four-node quadrilaterals, and 3D four-node shells and eight-node hexahedrons. All of the calculations are compared to the tests with respect to deformed shape and impact load history. As in the tests, the location of the instability is not consistent in all of the calculations. However, the calculations show good agreement with impact load measurements with the exception of an initial load spike which is proven to be the dynamic response of the load cell to the impact. Finally, the PRONIT02D calculation is compared to the tests with respect to strain and acceleration histories. Accelerometer data exhibited good qualitative agreement with the calculations. The strain comparisons show that measurements are very sensitive to gage placement.
Briggs, C.K.; Borg, I.Y.
1985-07-01
The 1984 energy flow diagram for the USA has been constructed using Department of Energy data. It is a convenient graphical device to show supply and demand as well as the size of end-use sectors. A 4% increase in overall energy consumption represented a reversal in a downward trend started in 1979. All indicators pointed to more healthy industrial and farm economies in 1984 than in the previous two years, which accounted for some part of the increase in energy use. While domestic crude oil production remained stable, oil imports rose eight percent also reversing a long-standing trend. Seventy-two million barrels of oil primarily from Mexico and the United Kingdom were added to the Strategic Petroleum Reserve bringing the total oil stored at year end to 451 million barrels. At the same time 49 million barrels of oil were produced from the government-owned Naval Petroleum Reserve No. 1 (Elk Hills, CA). Energy use in all end-use sectors grew in 1984 which is in keeping with increases in use of all types of fossil fuels as well as electricity. Increase in electrical power demand continued to exceed forecasts, and during 1984 contracts for imports to the northeast US were negotiated with Canada. Nuclear power contributed 15% of total power generated in the US. At year end there were 86 licensed reactors and 44 in either start-up or construction stages. Six were canceled or abandoned during construction during the year. 11 refs., 4 figs., 3 tabs.
Wheeler, Montgomery
1992-01-01
instrumentation effects schematic for positive tube axial acceleration. . . . . . . . 28 2. 7 Initialization parabolas of December 17, 1991 2. 8 Initialization parabolas of August 20, 1991 2. 9 Initialization parabola of January 23, 1992 3. 1 Annular flow... uncorrected data and calibration, offset, and hydrostatic head corrected pressure drop data. . 4. 2 Reduced acceleration friction pressure drops for separate adiabatic test sections 4. 3 Comparison of friction pressure drops in reduced acceleration and I-g...
Miles, Robin R. (Danville, CA); Benett, William J. (Livermore, CA); Coleman, Matthew A. (Oakland, CA); Pearson, Francesca S. (Livermore, CA); Nasarabadi, Shanavaz L. (Livermore, CA)
2011-03-08
A lateral flow strip assay apparatus comprising a housing; a lateral flow strip in the housing, the lateral flow strip having a receiving portion; a sample collection unit; and a reagent reservoir. Saliva and/or buccal cells are collected from an individual using the sample collection unit. The sample collection unit is immersed in the reagent reservoir. The tip of the lateral flow strip is immersed in the reservoir and the reagent/sample mixture wicks up into the lateral flow strip to perform the assay.
Bell, Geoffrey C. (Pleasant Hill, CA); Feustel, Helmut E. (Albany, CA); Dickerhoff, Darryl J. (Berkeley, CA)
2002-01-01
A fume hood is provided having an adequate level of safety while reducing the amount of air exhausted from the hood. A displacement flow fume hood works on the principal of a displacement flow which displaces the volume currently present in the hood using a push-pull system. The displacement flow includes a plurality of air supplies which provide fresh air, preferably having laminar flow, to the fume hood. The displacement flow fume hood also includes an air exhaust which pulls air from the work chamber in a minimally turbulent manner. As the displacement flow produces a substantially consistent and minimally turbulent flow in the hood, inconsistent flow patterns associated with contaminant escape from the hood are minimized. The displacement flow fume hood largely reduces the need to exhaust large amounts of air from the hood. It has been shown that exhaust air flow reductions of up to 70% are possible without a decrease in the hood's containment performance. The fume hood also includes a number of structural adaptations which facilitate consistent and minimally turbulent flow within a fume hood.
Air Flow Distribution in the Sales Area of a Supermarket
Fang, X.; Song, C.; Zhao, J.; Wang, Z.
2006-01-01
Many kinds of goods are displayed in a supermarket, which have their own particularities. The consumer flow rate is great and the type of shelved goods varies significantly, thereby influencing the objects that generate heat, and the demands of air...
Nonlinear springs with applications to flow regulation valves and mechanisms
Freeman, David Calvin
2008-01-01
This thesis focuses on the application of nonlinear springs for fluid flow control valves where geometric constraints, or fabrication technologies, limit the use of available solutions. Types of existing nonlinear springs ...
Energy flows in graphene: hot carrier dynamics and cooling
Song, Justin C. W.
Long lifetimes of hot carriers can lead to qualitatively new types of responses in materials. The magnitude and time scales for these responses reflect the mechanisms governing energy flows. We examine the microscopics of ...
Numerical analysis of vapor flow in a micro heat pipe
Liu, Xiaoqin
1996-01-01
The vapor flow in a flat plate micro heat pipe with both uniform and linear heat flux boundary conditions has been numerically analyzed. For both types of boundary conditions, the Navier-Stokes equations with steady incompressible two...
Measurement Of The Fluid Flow Load On A Globe Valve Stem Under Various Cavitation Conditions
Ferrari, Jerome
2009-01-01
The evaluation of fluid forces on the stem is important for wear prediction of valve and actuator guidance parts. While estimating the axial load is straight forward, estimating and/or measuring the side load is more difficult, especially for globe valves. Therefore, measurements are carried out on an ad hoc, scale 1, model of a 2" globe valve. The body is replicated in Plexiglas to enable flow visualization and the original stem is heavily instrumented to allow force measurements in every direction. The flow loop facility used for this experiment is designed to allow fine-tuning of the cavitation intensity. The experiment is run for a set of cavitation conditions, flow rates and disc positions. The results show that the transverse force (perpendicular to the stem) can reach the order of the axial force; thus it should not be ignored. We also observed that it depends very weakly on the cavitation levels. Videos made with a high-speed camera allow an interesting understanding of the fluid flow and the cavitati...
Hochreiter, L.E.; Basel, R.A.; Dennis, R.J.; Lee, N.; Massie, H.W. Jr.; Loftus, M.J.; Rosal, E.R.; Valkovic, M.M.
1980-10-01
This report presents a descriptive plan of tests for the 21-Rod Bundle Flow Blockage Task of the Full-Length Emergency Cooling Heat Transfer Separate Effects and Systems Effects Test Program (FLECHT SEASET). This task will consist of forced and gravity reflooding tests utilizing electrical heater rods to simulate PWR nuclear core fuel rod arrays. All tests will be performed with a cosine axial power profile. These tests are planned to be used to determine effects of various flow blockage configurations (shapes and distributions) on reflooding behavior, to aid in development/assessment of computational models in predicting reflooding behavior of flow blockage configurations, and to screen flow blockage configurations for future 161-rod flow blockage bundle tests.
Mare, Thierry; Voicu, Ionut; Miriel, Jacques [Laboratoire de Genie Civil et de Genie Mecanique (LGCGM), INSA de Rennes, IUT Saint Malo, 35043 Rennes (France); Galanis, Nicolas [Faculte de genie, Universite de Sherbrooke, Sherbrooke, QC (Canada); Sow, Ousmane [Laboratoire d'Energie Appliquee, Ecole superieure Polytechnique, Dakar (Senegal)
2008-04-15
Velocity vectors in a vertical coaxial double-duct heat exchanger for parallel ascending flow of water under conditions of laminar mixed convection have been determined experimentally using the particle image velocimetry technique. The measured velocity distributions for large annular flow rates, resulting in an essentially isothermal environment for the stream in the inner tube, are in very good agreement with corresponding numerical predictions. For flow rates of the same order of magnitude in the inner tube and the annulus, and corresponding temperature differences of about 20 C, experimental observations show that flow reversal occurs simultaneously in both streams over large axial distances for both heating and cooling of the flow in the inner tube. (author)
Koenig, W.M.; Hennecke, D.K.; Fottner, L.
1996-01-01
New blading concepts as used in modern transonic axial-flow compressors require improved loss and deviation angle correlations. The new model presented in this paper incorporates several elements and treats blade-row flows having subsonic and supersonic inlet conditions separately. The second part of the present report focuses on the extension of a well-known correlation for cascade losses at supersonic inlet flows. It was originally established for DCA bladings and is now modified to reflect the flow situation in blade rows having low-cambered, arbitrarily designed blades including precompression blades. Finally, the steady loss increase from subsonic to supersonic inlet-flow velocities demonstrates the matched performance of the different correlations of the new model.
Magnetic Amplifier for Power Flow Control
2012-02-24
GENI Project: ORNL is developing an electromagnet-based, amplifier-like device that will allow for complete control over the flow of power within the electric grid. To date, complete control of power flow within the grid has been prohibitively expensive. ORNL’s controller could provide a reliable, cost-effective solution to this problem. The team is combining two types of pre-existing technologies to assist in flow control, culminating in a prototype iron-based magnetic amplifier. Ordinarily, such a device would require expensive superconductive wire, but the magnetic iron core of ORNL’s device could serve as a low-cost alternative that is equally adept at regulating power flow.
A Typed Operational Semantics for Type Theory
Goguen, Healfdene
Untyped reduction provides a natural operational semantics for type theory. Normalization results say that such a semantics is sound. However, this reduction does not take type information into account and gives no information ...
Sweetspot: Near-infrared observations of 13 type Ia supernovae...
Office of Scientific and Technical Information (OSTI)
of 13 type Ia supernovae from a new NOAO survey probing the nearby smooth Hubble flow Citation Details In-Document Search Title: Sweetspot: Near-infrared observations of 13...
Modeling and Analysis of Two-Part Type Manufacturing Systems
Jang, Young Jae
This paper presents a model and analysis of a synchronous tandem flow line that produces different part types on unreliable machines. The machines operate according to a static priority rule, operating on the highest ...
Modeling of Seismic Signatures of Carbonate Rock Types
Jan, Badr H.
2011-02-22
Carbonate reservoirs of different rock types have wide ranges of porosity and permeability, creating zones with different reservoir quality and flow properties. This research addresses how seismic technology can be used to identify different...
Watt, J. B.; Haberl, J. S.
1994-01-01
or generate a totalized signal that can be recorded by data acquisition system. The accuracy of totalized flow and energy measurements is directly effected by the quality of thermal and flow measurement devices. In a closed-loop system a thermal energy meter... possible solution is to use a frequency to voltage converter between the magnetic paddlewheel flow meter and thermal energy meter to transform the sine wave to a square wave much like the signal generated by the non-magnetic-type meter (Doeblin 1990...
Rodriguez, Jose Ramon
2001-01-01
This experimental study investigates the effects of inclination angle and fluid viscosity on zero net liquid flow (ZNLF). Predicting liquid holdup under ZNLF conditions is necessary in several types of petroleum industry operations. These include...
Deformation Behavior and TExture Evolution of Steel Alloys under Axial-Torsional Loading
Siriruk, A.; Kant, M.; Penumadu, D.; Garlea, E.; Vogel, S.
2011-06-01
Using hollow cylinder samples with suitable geometry obtained from round bar stock, the deformation behavior of bcc Fe based 12L14 steel alloy is evaluated under multi-axial conditions. A stacked strain gage rosette and extensometer mounted on the cylindrical surface at the mid height of the specimen provided strain tensor as a function of applied stress for pure tensile and torsion tests prior to yielding. This study examines elastic and yield behavior and effects of these with respect to texture evolution. Hollow cylinder specimen geometry (tubes) with small wall thickness and relatively (to its thickness) large inner diameter is used. The variation of observed yield surface in deviatoric plane and the effect on mode of deformation (tension versus torsion versus its combination) on stress-strain behavior is discussed. Bulk texture was studied using neutron time-of-flight diffractometer at High-Pressure-Preferred Orientation (HIPPO) - Los Alamos Neutron Science Center (LANSCE) instrument and the evolution of texture and related anisotropy for pure tension versus torsion are also included.
Strain and stability of ultrathin Ge layers in Si/Ge/Si axial heterojunction nanowires
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
Ross, Frances M.; Stach, Eric A.; Wen, Cheng -Yen; Reuter, Mark C.; Su, Dong
2015-02-05
The abrupt heterointerfaces in the Si/Ge materials system presents useful possibilities for electronic device engineering because the band structure can be affected by strain induced by the lattice mismatch. In planar layers, heterointerfaces with abrupt composition changes are difficult to realize without introducing misfit dislocations. However, in catalytically grown nanowires, abrupt heterointerfaces can be fabricated by appropriate choice of the catalyst. Here we grow nanowires containing Si/Ge and Si/Ge/Si structures respectively with sub-1nm thick Ge "quantum wells" and we measure the interfacial strain fields using geometric phase analysis. Narrow Ge layers show radial strains of several percent, with a correspondingmore »dilation in the axial direction. Si/Ge interfaces show lattice rotation and curvature of the lattice planes. We conclude that high strains can be achieved, compared to what is possible in planar layers. In addition, we study the stability of these heterostructures under heating and electron beam irradiation. The strain and composition gradients are supposed to the cause of the instability for interdiffusion.« less
The twofold emergence of the $a_1$ axial vector meson in high energy hadronic production
Jean-Louis Basdevant; Edmond L. Berger
2015-01-19
The high statistics COMPASS results on diffractive dissociation $\\pi N \\rightarrow \\pi \\pi \\pi N$ suggest that the isospin $I=1$ spin-parity $J^{PC}= 1^{++}$ $a_1(1260)$ resonance could be split into two states: $a_1(1260)$ decaying into an S-wave $\\rho\\pi$ system, and $a_1^\\prime(1420)$ decaying into a P-wave $f_0(980)\\pi$ system. We analyse the reaction by incorporating our previous treatment of resonant re-scattering corrections in the Drell-Deck forward production process. Our results show that the COMPASS results are fully consistent with the existence of a single axial-vector $a_1$ resonance. The characteristic structure of the production process, which differs in the two orbital angular momentum states, plays a crucial role in this determination. Provided the theoretical analysis of the reaction is done in a consistent manner, this single resonance produces two peaks at different locations in the two channels, with a rapid increase of the phase difference between their amplitudes arising mainly from the structure of the production process itself, and not from a dynamical resonance effect. In addition, this analysis clarifies questions related to the mass, width, and decay rates of the $a_1$ resonance.
Radiant energy receiver having improved coolant flow control means
Hinterberger, H.
1980-10-29
An improved coolant flow control for use in radiant energy receivers of the type having parallel flow paths is disclosed. A coolant performs as a temperature dependent valve means, increasing flow in the warmer flow paths of the receiver, and impeding flow in the cooler paths of the receiver. The coolant has a negative temperature coefficient of viscosity which is high enough such that only an insignificant flow through the receiver is experienced at the minimum operating temperature of the receiver, and such that a maximum flow is experienced at the maximum operating temperature of the receiver. The valving is accomplished by changes in viscosity of the coolant in response to the coolant being heated and cooled. No remotely operated valves, comparators or the like are needed.
Flow patterns in vertical two-phase flow
McQuillan, K.W.; Whalley, P.B.
1985-03-01
This paper is concerned with the flow patterns which occur in upwards gas-liquid two-phase flow in vertical tubes. The basic flow patterns are described and the use of flow patter maps is discussed. The transition between plug flow and churn flow is modelled under the assumption that flooding of the falling liquid film limits the stability of plug flow. The resulting equation is combined with other flow pattern transition equations to produce theoretical flow pattern maps, which are then tested against experimental flow pattern data. Encouraging agreement is obtained.
Loftus, M J; Hochreiter, L E; McGuire, M F; Valkovic, M M
1983-10-01
This report presents data from the 163-Rod Bundle Blow Blockage Task of the Full-Length Emergency Cooling Heat Transfer Systems Effects and Separate Effects Test Program (FLECHT SEASET). The task consisted of forced and gravity reflooding tests utilizing electrical heater rods with a cosine axial power profile to simulate PWR nuclear core fuel rod arrays. These tests were designed to determine effects of flow blockage and flow bypass on reflooding behavior and to aid in the assessment of computational models in predicting the reflooding behavior of flow blockage in rod bundle arrays.
Zheng Peng; Hepeng Zheng; Yimin Jiang
2009-09-06
The flow of granular material through an orifice is studied experimentally as a function of force $F$ pushing the flow. It is found that the flow rate increases linearly with $F$ -- a new, unexpected result that is in contrast to the usual view that $F$, completely screened by an arch formed around the orifice, has no way of altering the rate. Employing energy balance, we show that this behavior results mainly from dissipation in the granular material.
Kumar S. Gupta; Siddhartha Sen
2010-06-05
We demonstrate the possibility of a turbulent flow of electrons in graphene in the hydrodynamic region, by calculating the corresponding turbulent probability density function. This is used to calculate the contribution of the turbulent flow to the conductivity within a quantum Boltzmann approach. The dependence of the conductivity on the system parameters arising from the turbulent flow is very different from that due to scattering.
Solids mass flow determination
Macko, Joseph E. (Hempfield Township, Westmoreland County, PA)
1981-01-01
Method and apparatus for determining the mass flow rate of solids mixed with a transport fluid to form a flowing mixture. A temperature differential is established between the solids and fluid. The temperature of the transport fluid prior to mixing, the temperature of the solids prior to mixing, and the equilibrium temperature of the mixture are monitored and correlated in a heat balance with the heat capacities of the solids and fluid to determine the solids mass flow rate.
Malkowski, S; Hona, B; Mattie, C; Woods, D; Yan, H; Plaster, B; 10.1063/1.3605665
2011-01-01
Metglas 2705M is a low-cost commercially-available, high-permeability Cobalt-based magnetic alloy, provided as a 5.08-cm wide and 20.3-$\\mu$m thick ribbon foil. We present an optimized construction technique for single-shell, large-scale (human-size), thin, open-ended cylindrical Metglas magnetic shields. The measured DC axial and transverse magnetic shielding factors of our 0.61-m diameter and 1.83-m long shields in the Earth's magnetic field were 267 and 1500, for material thicknesses of only 122 $\\mu$m (i.e., 6 foil layers). The axial shielding performance of our single-shell Metglas magnetic shields, obtained without the use of magnetic shaking techniques, is comparable to the performance of significantly thicker, multiple-shell, open-ended Metglas magnetic shields in comparable-magnitude, low-frequency applied external fields reported previously in the literature.
Wang, Jing [Department of Materials Science and Engineering, Texas A and M University, College Station, Texas 77843 (United States); Chen, Di; Wallace, Joseph; Gigax, Jonathan; Wang, Xuemei [Department of Nuclear Engineering, Texas A and M University, College Station, Texas, 77843 (United States); Shao, Lin, E-mail: lshao@tamu.edu [Department of Materials Science and Engineering, Texas A and M University, College Station, Texas 77843 (United States); Department of Nuclear Engineering, Texas A and M University, College Station, Texas, 77843 (United States)
2014-05-12
Through integrated molecular dynamics (MD) simulations and experimental studies, we demonstrated the feasibility of an ion-irradiation-and-annealing based phonon engineering technique to enhance thermal conductivity of carbon nanotube (CNT) films. Upon ion irradiation of CNT films, both inter-tube defects and intra-tube defects are introduced. Our MD simulations show that inter-tube defects created between neighboring tubes are much more stable than intra-tube defects created on tube graphitic planes. Upon thermal annealing, intra-tube defects are preferentially removed but inter-tube defects stay. Consequently, axial phonon transport increases due to reduced phonon scattering and off-axial phonon transport is sustained due to the high stability of inter-tube defects, leading to a conductivity enhancement upon annealing. The modeling predictions agree with experimental observations that thermal conductivities of CNT films were enhanced after 2?MeV hydrogen ion irradiations and conductivities were further enhanced upon post irradiation annealing.
Modeling of Breaching Due to Overtopping Flow and Waves Based on Coupled Flow and Sediment Transport
He, Zhiguo; Zhao, Liang; Wu, Ganfeng; Pähtz, Thomas
2015-01-01
Breaching of earthen or sandy dams/dunes by overtopping flow and waves is a complicated process with strong, unsteady flow, high sediment transport, and rapid bed changes in which the interactions between flow and morphology should not be ignored. This study presents a depth-averaged two-dimensional (2D) coupled flow and sediment transport model to investigate the flow and breaching processes with and without waves. Bed change and variable flow density are included in the flow continuity and momentum equations to consider the impacts of sediment transport. The model adopts the non-equilibrium approach for total-load sediment transport and specifies different repose angles to handle non-cohesive embankment slope avalanching. The equations are solved using an explicit finite volume method on a rectangular grid with the improved Godunov-type central upwind scheme and the nonnegative reconstruction of the water depth method to handle mixed-regime flows near the breach. The model has been tested against two sets o...
E. A. Gurnevich; P. V. Molchanov
2014-07-31
The behavior of the generation efficiency and radiation spectrum of a three-cavity axial vircator versus the radius of the injected electron beam, its impedance and energy homogeneity is studied. This paper establishes that for each geometry of a three-cavity resonator, there exist the optimal (maximizing the generation efficiency) values of these parameters and determines the range within which they may vary without losing the efficiency of generation.
Nesterenko, A V
2015-01-01
The dispersive approach to QCD, which properly embodies the intrinsically nonperturbative constraints originating in the kinematic restrictions on relevant physical processes and extends the applicability range of perturbation theory towards the infrared domain, is briefly overviewed. The study of OPAL (update 2012) and ALEPH (update 2014) experimental data on inclusive tau lepton hadronic decay in vector and axial-vector channels within dispersive approach is presented.
Gissinger, Christophe
's dynamo. DOI: 10.1103/PhysRevLett.108.234501 PACS numbers: 91.25.Cw, 47.20.Ky, 47.65.Àd, 52.65.Kj by a turbulent von Ka´rma´n swirling flow of liquid sodium due to two counter-rotating bladed disks [4
Parnell, Scott Edward
2005-02-17
............................... 30 4. Regulation of Cerebral Blood Flow by Changes in Metabolism ................... 32 5. Binge-Type Exposure Paradigm .................................................................... 41 6. Blood Flow in the Frontal Cortex at the 0... .............................. 19 Regulation of Cerebral Blood Flow ............................................... 21 Developmental Changes in the Regulation of CBF ....................... 34 Fetal Cerebral Blood Flow and Alcohol...
R. J. Hendricks; E. S. Phillips; D. M. Segal; R. C. Thompson
2007-09-24
Ions stored in Penning traps may have useful applications in the field of quantum information processing. There are, however, difficulties associated with the laser cooling of one of the radial motions of ions in these traps, namely the magnetron motion. The application of a small radio-frequency quadrupolar electric potential resonant with the sum of the two radial motional frequencies has been shown to couple these motions and to lead to more efficient laser cooling. We present an analytical model that enables us to determine laser cooling rates in the presence of such an 'axializing' field. It is found that this field leads to an averaging of the laser cooling rates for the two motions and hence improves the overall laser cooling efficiency. The model also predicts shifts in the motional frequencies due to the axializing field that are in qualitative agreement with those measured in recent experiments. It is possible to determine laser cooling rates experimentally by studying the phase response of the cooled ions to a near resonant excitation field. Using the model developed in this paper, we study the expected phase response when an axializing field is present.
Mitri, F.G.
2014-03-15
The axial and transverse radiation forces on a fluid sphere placed arbitrarily in the acoustical field of Bessel beams of standing waves are evaluated. The three-dimensional components of the time-averaged force are expressed in terms of the beam-shape coefficients of the incident field and the scattering coefficients of the fluid sphere using a partial-wave expansion (PWE) method. Examples are chosen for which the standing wave field is composed of either a zero-order (non-vortex) Bessel beam, or a first-order Bessel vortex beam. It is shown here, that both transverse and axial forces can push or pull the fluid sphere to an equilibrium position depending on the chosen size parameter ka (where k is the wave-number and a the sphere’s radius). The corresponding results are of particular importance in biophysical applications for the design of lab-on-chip devices operating with Bessel beams standing wave tweezers. Moreover, potential investigations in acoustic levitation and related applications in particle rotation in a vortex beam may benefit from the results of this study. -- Highlights: •The axial and transverse forces on a fluid sphere in acoustical Bessel beams tweezers are evaluated. •The attraction or repulsion to an equilibrium position in the standing wave field is examined. •Potential applications are in particle manipulation using standing waves.
Dynamics of multiple viscoelastic carbon nanotube based nanocomposites with axial magnetic field
Karli?i?, Danilo; Caji?, Milan; Murmu, Tony; Kozi?, Predrag; Adhikari, Sondipon
2014-06-21
Nanocomposites and magnetic field effects on nanostructures have received great attention in recent years. A large amount of research work was focused on developing the proper theoretical framework for describing many physical effects appearing in structures on nanoscale level. Great step in this direction was successful application of nonlocal continuum field theory of Eringen. In the present paper, the free transverse vibration analysis is carried out for the system composed of multiple single walled carbon nanotubes (MSWCNT) embedded in a polymer matrix and under the influence of an axial magnetic field. Equivalent nonlocal model of MSWCNT is adopted as viscoelastically coupled multi-nanobeam system (MNBS) under the influence of longitudinal magnetic field. Governing equations of motion are derived using the Newton second low and nonlocal Rayleigh beam theory, which take into account small-scale effects, the effect of nanobeam angular acceleration, internal damping and Maxwell relation. Explicit expressions for complex natural frequency are derived based on the method of separation of variables and trigonometric method for the “Clamped-Chain” system. In addition, an analytical method is proposed in order to obtain asymptotic damped natural frequency and the critical damping ratio, which are independent of boundary conditions and a number of nanobeams in MNBS. The validity of obtained results is confirmed by comparing the results obtained for complex frequencies via trigonometric method with the results obtained by using numerical methods. The influence of the longitudinal magnetic field on the free vibration response of viscoelastically coupled MNBS is discussed in detail. In addition, numerical results are presented to point out the effects of the nonlocal parameter, internal damping, and parameters of viscoelastic medium on complex natural frequencies of the system. The results demonstrate the efficiency of the suggested methodology to find the closed form solutions for the free vibration response of multiple nanostructure systems under the influence of magnetic field.
Broader source: Energy.gov [DOE]
Several commissioning types exist to address the specific needs of equipment and systems across both new and existing buildings. The following commissioning types provide a good overview.
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
Appointment Types Postdoc Appointment Types Most postdocs will be offered a postdoctoral research associate appointment. Each year, approximately 30 Postdoctoral Fellow...
Mitchell, Randall J.
1 Productivity & Energy Flow Ecosystem approach, focuses: on flow of energy, water, and nutrients (capture) of energy by autotrophs Gross (total) Net (total costs) Secondary productivity- capture of energy by herbivores http://sciencebitz.com/?page_id=204 What Controls the Primary Productivity
Microelectromechanical flow control apparatus
Okandan, Murat (NE Albuquerque, NM)
2009-06-02
A microelectromechanical (MEM) flow control apparatus is disclosed which includes a fluid channel formed on a substrate from a first layer of a nonconducting material (e.g. silicon nitride). A first electrode is provided on the first layer of the nonconducting material outside the flow channel; and a second electrode is located on a second layer of the nonconducting material above the first layer. A voltage applied between the first and second electrodes deforms the fluid channel to increase its cross-sectional size and thereby increase a flow of a fluid through the channel. In certain embodiments of the present invention, the fluid flow can be decreased or stopped by applying a voltage between the first electrode and the substrate. A peristaltic pumping of the fluid through the channel is also possible when the voltage is applied in turn between a plurality of first electrodes and the substrate. A MEM flow control assembly can also be formed by providing one or more MEM flow control devices on a common substrate together with a submicron filter. The MEM flow control assembly can optionally include a plurality of pressure sensors for monitoring fluid pressure and determining flow rates through the assembly.
1999 by Glenn Ballard and Iris Tommelein, All Rights Reserved Aiming for Continuous Flow
Tommelein, Iris D.
AND OBJECTIVES A continuous flow process (CFP) is a type of production line through which work is advanced from, specifically about continuous flow processes (CFPs)-- construction's 'assembly lines'. TERMINOLOGY can be planned. EXAMPLES OF CONTINUOUS FLOW PROCESSES Consider the following examples of CFPs
Potsaid, Benjamin M.
We demonstrate ultrahigh speed swept source/Fourier domain ophthalmic OCT imaging using a short cavity swept laser at 100,000 – 400,000 axial scan rates. Several design configurations illustrate tradeoffs in imaging speed, ...
Dunand, Matthieu
2010-01-01
The development of ductile fracture models of metals requires reliable measurements of the stress and strain histories up to the onset of fracture in multi-axial experiments. In the present work, a hybrid experimental-numerical ...
Types of Lights Types of Lights
1 Types of Lights Types of Lights q So far we have studied point lights Radiate in all direc7ons q Other lights Direc7onal lights (posi7on-independent) Spotlights #12;2 Direc1onal Lights q Shine in a single, uniform direc7on q All rays
Lopez, Jose M; Avila, Marc
2015-01-01
The flow of fluid confined between a heated rotating cylinder and a cooled stationary cylinder is a canonical experiment for the study of heat transfer in engineering. The theoretical treatment of this system is greatly simplified if the cylinders are assumed to be of infinite length or periodic in the axial direction, in which cases heat transfer occurs only through conduction as in a solid. We here investigate numerically heat transfer and the onset of turbulence in such flows by using both periodic and no-slip boundary conditions in the axial direction. We obtain a simple linear criterion that determines whether the infinite-cylinder assumption can be employed. The curvature of the cylinders enters this linear relationship through the slope and additive constant. For a given length-to-gap aspect ratio there is a critical Rayleigh number beyond which the laminar flow in the finite system is convective and so the behaviour is entirely different from the periodic case. The criterion does not depend on the Pra...
Effect of flow fluctuations and nonflow on elliptic flow methods
Ollitrault, Jean-Yves
2009-01-01
24.10.Nz I. INTRODUCTION II. FLOW METHODS Elliptic ?ow hasin the participant plane. Flow methods involve variousow e?ects are negligible. Flow ?uctuations modify both the
A flowing plasma model to describe drift waves in a cylindrical helicon discharge
Chang, L.; Hole, M. J.; Corr, C. S.
2011-04-15
A two-fluid model developed originally to describe wave oscillations in the vacuum arc centrifuge, a cylindrical, rapidly rotating, low temperature, and confined plasma column, is applied to interpret plasma oscillations in a RF generated linear magnetized plasma [WOMBAT (waves on magnetized beams and turbulence)], with similar density and field strength. Compared to typical centrifuge plasmas, WOMBAT plasmas have slower normalized rotation frequency, lower temperature, and lower axial velocity. Despite these differences, the two-fluid model provides a consistent description of the WOMBAT plasma configuration and yields qualitative agreement between measured and predicted wave oscillation frequencies with axial field strength. In addition, the radial profile of the density perturbation predicted by this model is consistent with the data. Parameter scans show that the dispersion curve is sensitive to the axial field strength and the electron temperature, and the dependence of oscillation frequency with electron temperature matches the experiment. These results consolidate earlier claims that the density and floating potential oscillations are a resistive drift mode, driven by the density gradient. To our knowledge, this is the first detailed physics model of flowing plasmas in the diffusion region away from the RF source. Possible extensions to the model, including temperature nonuniformity and magnetic field oscillations, are also discussed.
OPTIMIZATION OF COAL PARTICLE FLOW PATTERNS IN LOW NOX BURNERS
Jost O.L. Wendt; Gregory E. Ogden; Jennifer Sinclair; Stephanus Budilarto
2001-09-04
It is well understood that the stability of axial diffusion flames is dependent on the mixing behavior of the fuel and combustion air streams. Combustion aerodynamic texts typically describe flame stability and transitions from laminar diffusion flames to fully developed turbulent flames as a function of increasing jet velocity. Turbulent diffusion flame stability is greatly influenced by recirculation eddies that transport hot combustion gases back to the burner nozzle. This recirculation enhances mixing and heats the incoming gas streams. Models describing these recirculation eddies utilize conservation of momentum and mass assumptions. Increasing the mass flow rate of either fuel or combustion air increases both the jet velocity and momentum for a fixed burner configuration. Thus, differentiating between gas velocity and momentum is important when evaluating flame stability under various operating conditions. The research efforts described herein are part of an ongoing project directed at evaluating the effect of flame aerodynamics on NO{sub x} emissions from coal fired burners in a systematic manner. This research includes both experimental and modeling efforts being performed at the University of Arizona in collaboration with Purdue University. The objective of this effort is to develop rational design tools for optimizing low NO{sub x} burners. Experimental studies include both cold-and hot-flow evaluations of the following parameters: primary and secondary inlet air velocity, coal concentration in the primary air, coal particle size distribution and flame holder geometry. Hot-flow experiments will also evaluate the effect of wall temperature on burner performance.
Analysis of Developing Gas/liquid Two-Phase Flows
Elena A. Tselishcheva; Michael Z. Podowski; Steven P. Antal; Donna Post Guillen; Matthias Beyer; Dirk Lucas
2010-06-01
The goal of this work is to develop a mechanistically based CFD model that can be used to simulate process equipment operating in the churn-turbulent regime. The simulations were performed using a state-of-the-art computational multiphase fluid dynamics code, NPHASE–CMFD [Antal et al,2000]. A complete four-field model, including the continuous liquid field and three dispersed gas fields representing bubbles of different sizes, was first carefully tested for numerical convergence and accuracy, and then used to reproduce the experimental results from the TOPFLOW test facility at Forschungszentrum Dresden-Rossendorf e.V. Institute of Safety Research [Prasser et al,2007]. Good progress has been made in simulating the churn-turbulent flows and comparison the NPHASE-CMFD simulations with TOPFLOW experimental data. The main objective of the paper is to demonstrate capability to predict the evolution of adiabatic churn-turbulent gas/liquid flows. The proposed modelling concept uses transport equations for the continuous liquid field and for dispersed bubble fields [Tselishcheva et al, 2009]. Along with closure laws based on interaction between bubbles and continuous liquid, the effect of height on air density has been included in the model. The figure below presents the developing flow results of the study, namely total void fraction at different axial locations along the TOPFLOW facility test section. The complete model description, as well as results of simulations and validation will be presented in the full paper.
Turbulent momentum pinch of diamagnetic flows in a tokamak
Lee, Jungpyo; Barnes, Michael
2013-01-01
The ion toroidal rotation in a tokamak consists of an $E\\times B$ flow due to the radial electric field and a diamagnetic flow due to the radial pressure gradient. The turbulent pinch of toroidal angular momentum due to the Coriolis force studied in previous work is only applicable to the $E\\times B$ flow. In this Letter, the momentum pinch for the rotation generated by the radial pressure gradient is calculated and is compared with the Coriolis pinch. This distinction is important for subsonic flows or the flow in the pedestal where the two types of flows are similar in size and opposite in direction. In the edge, the different pinches due to the opposite rotations can result in intrinsic momentum transport that gives significant rotation peaking.
Bedrock Erosion by Granular Flow
Hsu, Leslie
2010-01-01
of boulders later in the flow when the matrix has thickenedMaximum height of the flow is 3.3 m. Appendix A true storyThe physics of debris flows, Reviews of Geophysics 35(3),
Magnetically stimulated fluid flow patterns
Martin, Jim; Solis, Kyle
2014-03-06
Sandia National Laboratories' Jim Martin and Kyle Solis explain research on the effects of magnetic fields on fluid flows and how they stimulate vigorous flows. Fluid flow is a necessary phenomenon in everything from reactors to cooling engines in cars.
Magnetically stimulated fluid flow patterns
Martin, Jim; Solis, Kyle
2014-08-06
Sandia National Laboratories' Jim Martin and Kyle Solis explain research on the effects of magnetic fields on fluid flows and how they stimulate vigorous flows. Fluid flow is a necessary phenomenon in everything from reactors to cooling engines in cars.
Redox Flow Batteries, a Review
Weber, Adam Z.
2013-01-01
of a Vanadium Redox-Flow Battery to Maintain Power Quality,"Fuel System Using Redox Flow Battery," ed: WO Patentand D. B. Hickey, "Redox Flow Battery System for Distributed
Fukuda, Takeshi; Ueda, Satoshi; Ohnishi, Yukihiro; Inomoto, Michiaki [Graduate School of Engineering, Osaka University, 2-1 Yamada-oka, Suita, 565-0871 Osaka (Japan)
2008-12-31
A compact 5 mm disk type plasma thruster simply composed of only a set of antenna windings and bias field coil which produces significant thrust of 0.74 mN with rotating magnetic field has been proposed and successfully developed for future applications to low altitude nanosatellites. The key technology issue is that the rotating speed is set above the ion plasma frequency but far below the electron plasma frequency, in order to produce the electron drag current and axial electric field as a consequence of the interaction with the bias field. The formation of axial electric field was confirmed and the produced plasma density was >6x10{sup 18} m{sup -3}, whereas the power consumption is 500 W in the inductively coupled mode of operation. The anticipated thrust density and specific thrust could potentially be extended to 7.64 Nm{sup -2} and 850 s, respectively, which is comparable to conventional Hall effect thrusters.
Controls of Wellbore Flow Regimes on Pump Effluent Composition
James Martin-Hayden; plummer; Sanford Britt
2014-01-01
Where well water and formation water are compositionally different or heterogeneous, pump effluent composition will vary due to partial mixing and transport induced by pumping. Investigating influences of purging and sampling methodology on composition variability requires quantification of wellbore flow regimes and mixing. As a basis for this quantification, analytical models simulating Poiseuille flow were developed to calculate flow paths and travel times. Finite element modeling was used to incorporate influences of mixing. Parabolic velocity distributions within the screened interval accelerate with cumulative inflow approaching the pump intake while an annulus of inflowing formation water contracts uniformly to displace an axial cylinder of pre-pumping well water as pumping proceeds. Increased dispersive mixing forms a more diffuse formation water annulus and the contribution of formation water to pump effluent increases more rapidly. Models incorporating viscous flow and diffusion scale mixing show that initially pump effluent is predominantly pre-pumping well water and compositions vary most rapidly. After two screen volumes of pumping, 94% of pump effluent is inflowing formation water. Where the composition of formation water and pre-pumping well water are likely to be similar, pump effluent compositions will not vary significantly and may be collected during early purging or with passive sampling. However, where these compositions are expected to be considerably different or heterogeneous, compositions would be most variable during early pumping, that is, when samples are collected during low-flow sampling. Purging of two screen volumes would be required to stabilize the content and collect a sample consisting of 94% formation water.
Enviro Hurdles: Instream Flow | Department of Energy
Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site
Hurdles: Instream Flow Enviro Hurdles: Instream Flow Enviro Hurdles: Instream Flow 76enviornlbevelhimer4.pptx More Documents & Publications Instream Flow Project Development and...
Flow cytometer jet monitor system
Van den Engh, Ger (Seattle, WA)
1997-01-01
A direct jet monitor illuminates the jet of a flow cytometer in a monitor wavelength band which is substantially separate from the substance wavelength band. When a laser is used to cause fluorescence of the substance, it may be appropriate to use an infrared source to illuminate the jet and thus optically monitor the conditions within the jet through a CCD camera or the like. This optical monitoring may be provided to some type of controller or feedback system which automatically changes either the horizontal location of the jet, the point at which droplet separation occurs, or some other condition within the jet in order to maintain optimum conditions. The direct jet monitor may be operated simultaneously with the substance property sensing and analysis system so that continuous monitoring may be achieved without interfering with the substance data gathering and may be configured so as to allow the front of the analysis or free fall area to be unobstructed during processing.
Moya, Maria J
2011-11-24
Long-distance bus companies, operate services along routes which have a flow of passengers. Along a route some passengers will leave the bus while others join. To monitor demand sufficiently well a tool is required which can help estimate...
none,
2012-05-01
This report documents findings from a workshop on the impacts of complex wind flows in and out of wind turbine environments, the research needs, and the challenges of meteorological and engineering modeling at regional, wind plant, and wind turbine scales.
Chan, Vincent W. S.
Present-day networks are being challenged by dramatic increases in bandwidth demand of emerging applications. We will explore a new transport, ldquooptical flow switchingrdquo, that will enable significant growth and ...
Parallel flow diffusion battery
Yeh, H.C.; Cheng, Y.S.
1984-01-01
A parallel flow diffusion battery for determining the mass distribution of an aerosol has a plurality of diffusion cells mounted in parallel to an aerosol stream, each diffusion cell including a stack of mesh wire screens of different density.
Parallel flow diffusion battery
Yeh, Hsu-Chi (Albuquerque, NM); Cheng, Yung-Sung (Albuquerque, NM)
1984-08-07
A parallel flow diffusion battery for determining the mass distribution of an aerosol has a plurality of diffusion cells mounted in parallel to an aerosol stream, each diffusion cell including a stack of mesh wire screens of different density.
Electrochemical flow capacitors
Gogotsi, Yury; Presser, Volker; Kumbar, Emin Caglan
2015-11-05
The present invention generally relates to devices for energy storage technologies, and more particularly to electrochemical flow capacitor systems and applications. In some aspects, these flow capacitors have at least one electrode comprising a non-stationary solid or semi-solid composition comprising supercapacitive particles and an electrolytic solvent in electrical communication with at least one current collector, and energy is stored and/or released by charging and/or discharging the electrode(s).
Electrochemical flow capacitors
Gogotsi, Yury; Presser, Volker; Kumbur, Emin Caglan
2015-10-27
The present invention generally relates to devices for energy storage technologies, and more particularly to electrochemical flow capacitor systems and applications. In some aspects, these flow capacitors have at least one electrode comprising a non-stationary solid or semi-solid composition comprising supercapacitive particles and an electrolytic solvent in electrical communication with at least one current collector, and energy is stored and/or released by charging and/or discharging the electrode(s).
Conjugate flow action functionals
Daniele Venturi
2013-10-15
We present a new general method to construct an action functional for a non-potential field theory. The key idea relies on representing the governing equations of the theory relative to a diffeomorphic flow of curvilinear coordinates which is assumed to be functionally dependent on the solution field. Such flow, which will be called the conjugate flow of the theory, evolves in space and time similarly to a physical fluid flow of classical mechanics and it can be selected in order to symmetrize the Gateaux derivative of the field equations with respect to suitable local bilinear forms. This is equivalent to requiring that the governing equations of the field theory can be derived from a principle of stationary action on a Lie group manifold. By using a general operator framework, we obtain the determining equations of such manifold and the corresponding conjugate flow action functional. In particular, we study scalar and vector field theories governed by second-order nonlinear partial differential equations. The identification of transformation groups leaving the conjugate flow action functional invariant could lead to the discovery of new conservation laws in fluid dynamics and other disciplines.
Computational Modeling of Blood Flow in the TrapEase Inferior Vena Cava Filter
Singer, M A; Henshaw, W D; Wang, S L
2008-02-04
To evaluate the flow hemodynamics of the TrapEase vena cava filter using three dimensional computational fluid dynamics, including simulated thrombi of multiple shapes, sizes, and trapping positions. The study was performed to identify potential areas of recirculation and stagnation and areas in which trapped thrombi may influence intrafilter thrombosis. Computer models of the TrapEase filter, thrombi (volumes ranging from 0.25mL to 2mL, 3 different shapes), and a 23mm diameter cava were constructed. The hemodynamics of steady-state flow at Reynolds number 600 was examined for the unoccluded and partially occluded filter. Axial velocity contours and wall shear stresses were computed. Flow in the unoccluded TrapEase filter experienced minimal disruption, except near the superior and inferior tips where low velocity flow was observed. For spherical thrombi in the superior trapping position, stagnant and recirculating flow was observed downstream of the thrombus; the volume of stagnant flow and the peak wall shear stress increased monotonically with thrombus volume. For inferiorly trapped spherical thrombi, marked disruption to the flow was observed along the cava wall ipsilateral to the thrombus and in the interior of the filter. Spherically shaped thrombus produced a lower peak wall shear stress than conically shaped thrombus and a larger peak stress than ellipsoidal thrombus. We have designed and constructed a computer model of the flow hemodynamics of the TrapEase IVC filter with varying shapes, sizes, and positions of thrombi. The computer model offers several advantages over in vitro techniques including: improved resolution, ease of evaluating different thrombus sizes and shapes, and easy adaptation for new filter designs and flow parameters. Results from the model also support a previously reported finding from photochromic experiments that suggest the inferior trapping position of the TrapEase IVC filter leads to an intra-filter region of recirculating/stagnant flow with very low shear stress that may be thrombogenic.
Zhang, Peng; Le, Son T.; Hou, Xiaoxiao; Zaslavsky, A.; Perea, Daniel E.; Dayeh, Shadi A.; Picraux, Samuel T.
2014-08-11
We report on room-temperature negative transconductance (NTC) in axial Si/Ge hetero-nanowire tunneling field-effect transistors (TFETs). The NTC produces a current peak-to-valley ratio > 45, a high value for a Si-based device. We characterize the NTC characteristics over a range of gate VG and drain VD voltages, finding that NTC persists down to VD = –50 mV. The physical mechanism responsible for the NTC is the VG-induced depletion in the p-Ge section that eventually reduces the maximum electric field that triggers the tunneling ID, as confirmed via three-dimensional TCAD simulations.
Observation of Pseudoscalar and Axial Vector Resonances in pi- p -> K+ K- pi0 n at 18 GeV
Adams, G S
2001-01-01
A new measurement of the reaction pi- p -> K+ K- pi0 n has been made at a beam energy of 18 GeV. A partial wave analysis of the K+ K- pi0 system shows evidence for three pseudoscalar resonances, eta(1295), eta(1416), and eta(1485), as well as two axial vectors, f1(1285), and f1(1420). Their observed masses, widths and decay properties are reported. No signal was observed for C(1480), an IG J{PC} = 1+ 1{--} state previously reported in phi pi0 decay.
Yatsenko, T.; Ilyenko, K.; Sotnikov, G. V.
2012-06-15
In the strong axial magnetic field approximation, we calculate the space-charge limited (SCL) current of axisymmetric relativistic charged-particle beam in a coaxial drift tube of finite length. Results are compared to analytical estimates and numerical modeling of SCL current in the infinitely long drift tube. For the infinitely long drift tube, which inner conductor is biased and the outer conductor is lined with a finite-width dielectric insert, analytic approximations for the SCL current in the bias voltage are developed.
Reichner, P.; Dollard, W.J.
1991-01-08
An electrochemical apparatus is made having a generator section containing axially elongated electrochemical cells, a fresh gaseous feed fuel inlet, a gaseous feed oxidant inlet, and at least one gaseous spent fuel exit channel, where the spent fuel exit channel passes from the generator chamber to combine with the fresh feed fuel inlet at a mixing apparatus, reformable fuel mixture channel passes through the length of the generator chamber and connects with the mixing apparatus, that channel containing entry ports within the generator chamber, where the axis of the ports is transverse to the fuel electrode surfaces, where a catalytic reforming material is distributed near the reformable fuel mixture entry ports. 2 figures.
Loftus, M.J.; Hochreiter, L.E.; Lee, N.; McGuire, M.F.; Wenzel, A.H.; Valkovic, M.M.
1982-09-01
This report presents data and limited analysis from the 21-Rod Bundle Flow Blockage Task of the Full-Length Emergency Cooling Heat Transfer Separate Effects and Systems Effects Test Program (FLECHT SEASET). The tests consisted of forced and gravity reflooding tests utilizing electrical heater rods with a cosine axial power profile to simulate PWR nuclear core fuel rod arrays. Steam cooling and hydraulic characteristics tests were also conducted. These tests were utilized to determine effects of various flow blockage configurations (shapes and distributions) on reflooding behavior, to aid in development/assessment of computational models in predicting reflooding behavior of flow blockage configurations, and to screen flow blockage configurations for future 163-rod flow blockage bundle tests.
Broader source: Energy.gov [DOE]
The following provides greater detail regarding the types of reuse pursued for LM sites. It should be noted that many actual reuses combine several types of the uses listed below.
Fluid Flow Estimation Through Integration of Physical Flow Configurations
Garbe, Christoph S.
Fluid Flow Estimation Through Integration of Physical Flow Configurations Christoph S. Garbe IWR, University of Heidelberg Christoph.Garbe@iwr.uni-heidelberg.de Abstract. The measurement of fluid flows is an emerging field for op- tical flow computation. In a number of such applications, a tracer is visualized
Energy Flow Energy Flow Energy Flow A.Ukleja, T.Tymieniecka, I.Skillicorn 1 Azimuthal asymmetry
Energy Flow Energy Flow Energy Flow A.Ukleja, T.Tymieniecka, I.Skillicorn 1 Azimuthal asymmetry using energy flow method Azimuthal angle distribution at Q2 >100 GeV2 Energy flow method.Ukleja on behalf of the ZEUS Collaboration #12; Energy Flow Energy Flow Energy Flow A.Ukleja, T.Tymieniecka, I
Flow Batteries A Historical Perspective
Flow Batteries A Historical Perspective Robert F. Savinell Case Western Reserve University Department of Chemical Engineering DOE Flow Battery Workshop March 2012 #12;2 OUTLINE ·The first flow cell? ·Review articles- documented progress ·Early NASA Work- some learning ·Fuel Cell and Flow Battery
Hanold, R.J.
1983-12-01
The two-phase flow program is directed at understanding the hydrodynamics of two-phase flows. The two-phase flow regime is characterized by a series of flow patterns that are designated as bubble, slug, churn, and annular flow. Churn flow has received very little scientific attention. This lack of attention cannot be justified because calculations predict that the churn flow pattern will exist over a substantial portion of the two-phase flow zone in producing geothermal wells. The University of Houston is experimentally investigating the dynamics of churn flow and is measuring the holdup over the full range of flow space for which churn flow exists. These experiments are being conducted in an air/water vertical two-phase flow loop. Brown University has constructed and is operating a unique two-phase flow research facility specifically designed to address flow problems of relevance to the geothermal industry. An important feature of the facility is that it is dedicated to two-phase flow of a single substance (including evaporation and condensation) as opposed to the case of a two-component two-phase flow. This facility can be operated with horizontal or vertical test sections of constant diameter or with step changes in diameter to simulate a geothermal well profile.
Said Abdel-Khalik
2005-07-02
Axial offset anomaly (AOA) in pressurized water reactors refers to the presence of a significantly larger measured negative axial offset deviation than predicted by core design calculations. The neutron flux depression in the upper half of high-power rods experiencing significant subcooled boiling is believed to be caused by the concentration of boron species within the crud layer formed on the cladding surface. Recent investigations of the root-cause mechanism for AOA [1,2] suggest that boron build-up on the fuel is caused by precipitation of lithium metaborate (LiBO2) within the crud in regions of subcooled boiling. Indirect evidence in support of this hypothesis was inferred from operating experience at Callaway, where lithium return and hide-out were, respectively, observed following power reductions and power increases when AOA was present. However, direct evidence of lithium metaborate precipitation within the crud has, heretofore, not been shown because of its retrograde solubility. To this end, this investigation has been undertaken in order to directly verify or refute the proposed root-cause mechanism of AOA, and examine the effectiveness of possible mitigating actions to limit its impact in high power PWR cores.
TYPES OF NONIMMIGRANT VISAS Type Description
for pleasure and cannot receive any type of payments. C-1*, Aliens in travel status while travelling directly through the C-2*, United States. C-3* D-1 Alien crewman on shore leave or transferring to another vessel is grounds for deportation. E-1 Aliens who conduct trade or inventories between the United States
Peter A. Thomas
1996-08-20
I discuss the multiphase nature of the intracluster medium whose neglect can lead to overestimates of the baryon fraction of clusters by up to a factor of two. The multiphase form of the cooling flow equations are derived and reduced to a simple form for a wide class of self-similar density distributions. It is shown that steady-state cooling flows are \\emph{not} consistent with all possible emissivity profiles which can therefore be used as a test of the theory. In combination, they provide strong constraints on the mass distribution within the cooling radius.
Variable Refrigerant Flow HVAC
Jones, S.
2013-01-01
Variable refrigerant flow technology HVAC CATEE 2013 San Antonio, TX ESL-KT-13-12-33 CATEE 2013: Clean Air Through Energy Efficiency Conference, San Antonio, Texas Dec. 16-18 What is the acronym VRF? ? Variable Refrigerant Flow Operates like a... heat pump utilizing VFD Inverter Compressors and LEV’s Unlike conventional commercial and residential HVAC systems in the USA The predominate method of cooling and heating in the world ESL-KT-13-12-33 CATEE 2013: Clean Air Through Energy Efficiency...
Spraying Powder Materials by the High-Enthalpy Laminar Plasma Flow
Khutsishvili, M.; Kikvadze, L.
2008-03-19
One of the most promising engineering solutions of the problem of spraying powder materials is the proposed method of plasma spraying by the laminar plasma jet. Laminar plasma flow is characterized by small jet angle divergence; the powder particles are penetrated and accelerated mainly in the axial direction. The molten powder particles are transported almost to the surface of a treated work-piece inside the laminar plasma flow in an atmosphere of the plasma-forming gas with the acceleration on the entire transfer area, which leads to an increase in the particles velocity, a decrease of their oxidability, an increase in the powder deposition efficiency, density, adhesion strength with the surface to be coated.
Kenji Fukushima
2015-08-23
To address a question of whether the chiral magnetic current is a static polarization or a genuine flow of charged particles, we elucidate the numerical formulation to simulate the net production of right-handed particles and anomalous currents with CP-breaking background fields which cause an imbalance between particles and anti-particles. For a concrete demonstration we numerically impose pulsed electric and magnetic fields to confirm our answer to the question that the produced net particles flow in the dynamical chiral magnetic effect. The rate for the particle production and the chiral magnetic current generation is quantitatively consistent with the axial anomaly, while they appear with a finite response time. We emphasize the importance to quantify the response time that would suppress observable effects of the anomalous current.
Magnetic field distribution in the plasma flow generated by a plasma focus discharge
Mitrofanov, K. N.; Krauz, V. I. Myalton, V. V.; Velikhov, E. P.; Vinogradov, V. P.; Vinogradova, Yu. V.
2014-11-15
The magnetic field in the plasma jet propagating from the plasma pinch region along the axis of the chamber in a megajoule PF-3 plasma focus facility is studied. The dynamics of plasma with a trapped magnetic flow is analyzed. The spatial sizes of the plasma jet region in which the magnetic field concentrates are determined in the radial and axial directions. The magnetic field configuration in the plasma jet is investigated: the radial distribution of the azimuthal component of the magnetic field inside the jet is determined. It is shown that the magnetic induction vector at a given point in space can change its direction during the plasma flight. Conclusions regarding the symmetry of the plasma flow propagation relative to the chamber axis are drawn.
Loss mechanisms in turbine tip clearance flows
Huang, Arthur (Arthur C.)
2011-01-01
Numerical simulations of tip clearance ow have been carried out to dene the loss generation mechanisms associated with tip leakage in unshrouded axial turbines. Mix- ing loss between the leakage, which takes the form of a ...
Kumar, Narender; Rodrigues, G., E-mail: gerosro@gmail.com; Lakshmy, P. S.; Mathur, Y.; Ahuja, R.; Kanjilal, D. [Inter University Accelerator Centre, Aruna Asaf Ali Marg, New Delhi (India)] [Inter University Accelerator Centre, Aruna Asaf Ali Marg, New Delhi (India); Baskaran, R. [Indira Gandhi Centre for Atomic Research, Kalpakkam, Tamilnadu (India)] [Indira Gandhi Centre for Atomic Research, Kalpakkam, Tamilnadu (India)
2014-02-15
A compact microwave ion source has been designed and developed for operation at a frequency of 2.45 GHz. The axial magnetic field is based on two permanent magnet rings, operating in the “off-resonance” mode and is tunable by moving the permanent magnets. In order to understand the electron energy distribution function, x-ray bremsstrahlung has been measured in the axial direction. Simulation studies on the x-ray bremsstrahlung have been carried out to compare with the experimental results. The effect of the axial magnetic field with respect to the microwave launching position and the position of the extraction electrode on the x-ray bremsstrahlung have been studied.
Fatemeh Bagheri; Reza Mansouri
2014-08-03
Applying the method of conformal metric to a given static axially symmetric vacuum solution of the Einstein equations, we have shown that there is no solution representing a cosmic ideal fluid which is asymtotically FLRW. Letting the cosmic fluid to be imperfect there are axially symmetric solutions tending to FLRW at space infinity. The solution we have found represents an axially symmetric spacetime leading to a spherically symmetric Einstein tensor. Therefore, we have found a solution of Einstein equations representing a spherically symmetric matter distribution corresponding to a spacetime which does not reflect the same symmetry. We have also found another solution of Einstein equation corresponding to the same energy tensor with spherical symmetry.
Koenig, W.M.; Hennecke, D.K.; Fottner, L.
1996-01-01
New blading concepts as used in modern transonic axial-flow compressors require improved loss and deviation angle correlations. The new model presented in this paper incorporates several elements and treats blade-row flows having subsonic and supersonic inlet conditions separately. In the first part of this paper two proved and well-established profile loss correlations for subsonic flows are extended to quasi-two-dimensional conditions and to custom-tailored blade designs. Instead of a deviation angle correlation, a simple method based on singularities is utilized. The comparison between the new model and a recently published model demonstrates the improved accuracy in prediction of cascade performance achieved by the new model.
Pinkel, Daniel (Walnut Creek, CA)
1991-01-01
An obstruction across the flow chamber creates a one dimensional convergence of a sheath fluid. A passageway in the construction directs flat cells near to the area of one dimensional convergence in the sheath fluid to provide proper orientation of flat cells at fast rates.
Borg, I.Y.; Briggs, C.K.
1992-06-01
Trends in energy consumption and assessment of energy sources are discussed. Specific topics discussed include: energy flow charts; comparison of energy use with 1990 and earlier years; supply and demand of fossil fuels (oils, natural gas, coal); electrical supply and demand; and nuclear power.
Pinkel, D.
1987-11-30
An obstruction across the flow chamber creates a one-dimensional convergence of a sheath fluid. A passageway in the obstruction directs flat cells near to the area of one-dimensional convergence in the sheath fluid to provide proper orientation of flat cells at fast rates. 6 figs.
Schwartz, Stephen E.
ENERGY FLOWS FORCINGS CLIMATE CHANGE A REALLY TOUGH PROBLEM Stephen E. Schwartz, BNL, 7-20-11 www average temperature 15Â°C or 59Â°F #12;ATMOSPHERIC RADIATION Power per area Energy per time per area Unit" temperature to radiative flux. #12;GLOBAL ENERGY BALANCE Global and annual average energy fluxes in watts per
Stachiv, I., E-mail: stachiv@fzu.cz [Institute of Physics, Czech Academy of Sciences, Prague (Czech Republic); Advanced Manufacturing Institute with High-Tech Innovations, National Chung Cheng University, Chiayi County, Taiwan (China); Zapomel, J. [Institute of Thermomechanics, Czech Academy of Sciences, Prague (Czech Republic); Chen, Y.-L. [Institute of Physics, Academia Sinica, Taipei, Taiwan (China); Department of Physics, National Taiwan University, Taipei, Taiwan (China); Department of Chemical Engineering, National Tsing-Hua University, Hsinchu, Taiwan (China)
2014-03-28
Thin films are widely used in microelectronics, optics, filters, and various sensing devices. We propose a method to simultaneously determine the elastic modulus and density or thickness of ultrathin films deposited on various substrate materials. This methodology utilizes measurement of the resonant frequencies of the micro-/nanoresonator under intentionally applied axial tension and, consequently, the beam to string transition. Elastic modulus and density/thickness of thin film are obtained from the ratio between the resonant frequencies of the nanoresonator with and without applied axial force.
Prefabricated vertical drains flow resistance under vacuum conditions
Quaranta, J.D.; Gabr, M.A.
2000-01-01
The results of experimental research are presented and discussed with focus on the internal well resistance of prefabricated vertical drains (PVD) under vacuum-induced water flow. Measured results included fluid flow rates for two different cross-sectional hydraulic profiles (Types 1 and 2 PVDs). Experimental results indicated linear relationship, independent of the PVD widths, between extracted fluid velocity and the applied hydraulic gradient. Data showed a laminar flow regime to predominate for test velocities corresponding to hydraulic gradients {lt}0.5. The larger nominal hydraulic radius of the Type 2 PVD is credited with providing a flow rate equal to approximately 3.2 times that of the Type 1 PVD at approximately the same operating total head. There was no apparent dependency of the transmissivity {theta} on the width or lengths (3, 4, and 5 m) of the PVDs tested. In the case of the 100-mm-wide Type 1 PVD, {theta} = 618 mm{sup 2}/s was estimated from the measured data versus {theta} = 1,996 mm{sup 2}/s for Type 2 PVD with the same dimensions.
Eolian reservoir characteristics predicted from dune type
Kocurek, G.; Nielson, J.
1985-02-01
The nature of eolian-dune reservoirs is strongly influenced by stratification types (in decreasing order of quality: grain-flow, grain-fall, wind-ripple deposits) and their packaging by internal bounding surfaces. These are, in turn, a function of dune surface processes and migration behavior, allowing for predictive models of reservoir behavior. Migrating, simple crescentic dunes produce tabular bodies consisting mainly of grain-flow cross-strata, and form the best, most predictable reservoirs. Reservoir character improves as both original dune height and preserved set thickness increase, because fewer grain-fall deposits and a lower percentage of dune-apron deposits occur in the cross-strata, respectively. It is probable that many linear and star dunes migrate laterally, leaving a blanket of packages of wind ripple laminae reflecting deposition of broad, shifting aprons. This is distinct from models generated by freezing large portions of these dunes in place. Trailing margins of linear and star dunes are prone to reworking by sand-sheet processes that decrease potential reservoir quality. The occurrence of parabolic dunes isolated on vegetated sand sheets results in a core of grain-flow and grain-fall deposits surrounded by less permeable and porous deposits. Compound crescentic dunes, perhaps the most preservable dune type, may yield laterally (1) single sets of cross-strate, (2) compound sets derived from superimposed simple dunes, or (3) a complex of diverse sets derived from superimposed transverse and linear elements.
Brown, Matt
2013-01-01
type T y[O]. The operator IsIs is self-applicative, in thatargument t is any of Is[O] or IsIs, and otherwise behavesproof constant introduced by IsIs proves that the type of t
Chen, Shu-Hua
Effects of Moist Froude Number and CAPE on a Conditionally Unstable Flow over a Mesoscale Mountain- dimensional mountain ridge in order to investigate the propagation and types of cloud precipitation systems unstable flow passing over a two-dimensional mesoscale mountain ridge. The characteristics of these flow
Isaac, F.N.; Arkadan, A.A.; Russell, A.A. [Marquette Univ., Milwaukee, WI (United States)] [Marquette Univ., Milwaukee, WI (United States); El-Antably, A.
1998-09-01
In the last few years, increased attention has been paid to the performance characterization and evaluation of the performance of synchronous reluctance machines. Extensive research has concentrated on different rotor structures in order to achieve high performance variable speed drives for applications such as electric vehicles. The effects of accounting for anisotropy on the performance characteristics of Axially Laminated Anisotropic (ALA) rotor Synchronous Reluctance Motor (SynRM) drive systems are studied. These effects are evaluated from the simulations of a computer aided model. The model is based on the use of an iterative approach which indirectly couples a two dimensional (2D) nonlinear finite element (FE) model, which accounts for anisotropy, to a state space model describing the SynRM drive system. The simulation results are also validated by comparison to test data of a prototype ALA rotor SynRM drive system.
Observation of Pseudoscalar and Axial Vector Resonances in pi- p -> K+ K- pi0 n at 18 GeV
G.S. Adams; T. Adams; Z. Bar-Yam; J.M. Bishop; V.A. Bodyagin; D.S. Brown; N.M. Cason; S.U. Chung; J.P. Cummings; K. Danyo; A.I. Demianov; S. Denisov; V. Dorofeev; J.P. Dowd; P. Eugenio; X.L. Fan; A.M. Gribushin; R.W. Hackenburg; M. Hayek; J. Hu; E.I. Ivanov; D. Joffe; I. Kachaev; W. Kern; E. King; O.L. Kodolova; V.L. Korotkikh; M.A. Kostin; Joachim Kuhn; V. Lipaev; J.M. Losecco; M. Lu; J.J. Manak; J. Napolitano; M. Nozar; C. Olchanski; A.I. Ostrovidov; T.K. Pedlar; A. Popov; D. Ryabchikov; A.H. Sanjari; L.I. Sarycheva; K.K. Seth; N. Shenhav; X. Shen; W.D. Shephard; N.B. Sinev; D.L. Stienike; S.A. Taegar; D.R. Thompson; A. Tomaradze; I.N. Vardanyan; D.P. Weygand; D. White; H.J. Willutzki; A.A. Yershov
2001-09-01
The number of pseudoscalar mesons in the mass range from 1400 to 1500 MeV/c{sup 2} has been a subject of considerable interest for many years, with several experiments having presented evidence for two closely spaced states. A new measurement of the reaction {pi}{sup -} p {yields} K{sup +} K{sup -} {pi}{sup 0}n has been made at a beam energy of 18 GeV. A partial wave analysis of the K{sup +} K{sup -} {pi}{sup 0} system shows evidence for three pseudoscalar resonances, {eta}(1295), {eta}(1416), and {eta}(1485), as well as two axial vectors, f{sub 1}(1285), and f{sub 1}(1420). Their observed masses, widths and decay properties are reported. No signal was observed for C(1480), an I{sub G} J{sup PC} = 1{sup +} 1{sup --} state previously reported in {phi}{pi}{sup 0} decay.
Perkins, L. J.; Logan, B. G.; Zimmerman, G. B.; Werner, C. J.
2013-07-15
We report for the first time on full 2-D radiation-hydrodynamic implosion simulations that explore the impact of highly compressed imposed magnetic fields on the ignition and burn of perturbed spherical implosions of ignition-scale cryogenic capsules. Using perturbations that highly convolute the cold fuel boundary of the hotspot and prevent ignition without applied fields, we impose initial axial seed fields of 20–100 T (potentially attainable using present experimental methods) that compress to greater than 4 × 10{sup 4} T (400 MG) under implosion, thereby relaxing hotspot areal densities and pressures required for ignition and propagating burn by ?50%. The compressed field is high enough to suppress transverse electron heat conduction, and to allow alphas to couple energy into the hotspot even when highly deformed by large low-mode amplitudes. This might permit the recovery of ignition, or at least significant alpha particle heating, in submarginal capsules that would otherwise fail because of adverse hydrodynamic instabilities.
Sagar, Vikram; Sengupta, Sudip; Kaw, Predhiman [Institute for Plasma Research, Bhat, Gandhinagar 382428 (India)
2012-11-15
Dynamics of a charged particle is studied in the field of a relativistically intense linearly polarized finite duration laser pulse in the presence of a static axial magnetic field. For a finite duration laser pulse whose temporal shape is defined by Gaussian profile, exact analytical expressions are derived for the particle trajectory, momentum, and energy as function of laser phase. From the solutions, it is shown that, unlike for the monochromatic plane wave case, resonant phase locking time between the particle and laser pulse is finite. The net energy transferred to the particle does not increase monotonically but tends to saturate. It is further shown that appropriate tuning of cyclotron frequency of the particle with the characteristic frequency in the pulse spectrum can lead to the generation of accelerated particles with variable energies in MeV-TeV range.
Reichner, Philip (Plum Borough, PA); Dollard, Walter J. (Churchill Borough, PA)
1991-01-01
An electrochemical apparatus (10) is made having a generator section (22) containing axially elongated electrochemical cells (16), a fresh gaseous feed fuel inlet (28), a gaseous feed oxidant inlet (30), and at least one gaseous spent fuel exit channel (46), where the spent fuel exit channel (46) passes from the generator chamber (22) to combine with the fresh feed fuel inlet (28) at a mixing apparatus (50), reformable fuel mixture channel (52) passes through the length of the generator chamber (22) and connects with the mixing apparatus (50), that channel containing entry ports (54) within the generator chamber (22), where the axis of the ports is transverse to the fuel electrode surfaces (18), where a catalytic reforming material is distributed near the reformable fuel mixture entry ports (54).
Theoretical and experimental studies of churn flow in vertical tubes. Final technical report
Not Available
1986-01-27
The pattern known as churn flow is a highly unsteady pattern with stochastic features and is extremely complex. However, calculations show that for many geothermal wells the condition of churn flow consists over much of the length of the two phase zone. Furthermore, it frequently exists at the surface so that design of separation equipment and surface piping depends on the accurate modelling of this type of flow. It has been the long term purpose of this project to develop physically based models for churn flow which can be used as a basis for predicting holdup, frictional loss and heat transfer rates for this flow pattern in geothermal systems. To achieve this end, it was necessary to develop new methods for measuring the time dependent characteristics of the flow and thus be able to uncover the basic physics of the flow. Models can then be developed based on this understanding which characterizes the flow and equations for holdup, friction and heat transfer evolved.
Experimental and Analytic Study on the Core Bypass Flow in a Very High Temperature Reactor
Richard Schultz
2012-04-01
Core bypass flow has been one of key issues in the very high temperature reactor (VHTR) design for securing core thermal margins and achieving target temperatures at the core exit. The bypass flow in a prismatic VHTR core occurs through the control element holes and the radial and axial gaps between the graphite blocks for manufacturing and refueling tolerances. These gaps vary with the core life cycles because of the irradiation swelling/shrinkage characteristic of the graphite blocks such as fuel and reflector blocks, which are main components of a core's structure. Thus, the core bypass flow occurs in a complicated multidimensional way. The accurate prediction of this bypass flow and counter-measures to minimize it are thus of major importance in assuring core thermal margins and securing higher core efficiency. Even with this importance, there has not been much effort in quantifying and accurately modeling the effect of the core bypass flow. The main objectives of this project were to generate experimental data for validating the software to be used to calculate the bypass flow in a prismatic VHTR core, validate thermofluid analysis tools and their model improvements, and identify and assess measures for reducing the bypass flow. To achieve these objectives, tasks were defined to (1) design and construct experiments to generate validation data for software analysis tools, (2) determine the experimental conditions and define the measurement requirements and techniques, (3) generate and analyze the experimental data, (4) validate and improve the thermofluid analysis tools, and (5) identify measures to control the bypass flow and assess its performance in the experiment.
Supercritical flow in rectangular expansions
Walsh, Peter.
1968-01-01
In recent years the occasions for design of channels to contain supercritical flow has increased considerably. Consequently there has developed a need for a method of predicting the physical characteristics of such flow based on theory...
VanOsdol, John G.
2013-06-25
The disclosure provides a pulse jet mixing vessel for mixing a plurality of solid particles. The pulse jet mixing vessel is comprised of a sludge basin, a flow surface surrounding the sludge basin, and a downcoming flow annulus between the flow surface and an inner shroud. The pulse jet mixing vessel is additionally comprised of an upper vessel pressurization volume in fluid communication with the downcoming flow annulus, and an inner shroud surge volume separated from the downcoming flow annulus by the inner shroud. When the solid particles are resting on the sludge basin and a fluid such as water is atop the particles and extending into the downcoming flow annulus and the inner shroud surge volume, mixing occurs by pressurization of the upper vessel pressurization volume, generating an inward radial flow over the flow surface and an upwash jet at the center of the sludge basin.
HYDROLYZED WOOD SLURRY FLOW MODELING
Wrathall, Jim
2012-01-01
LBL-10090 UC-61 HYDROLYZED WOOD SLURRY FLOW MODELING JimLBL-10090 HYDROLYZED WOOD SLURRY FLOW MODELING Jim Wrathallconversion of hydrolyzed wood slurry to fuel oil, Based on
Structural power flow measurement
Falter, K.J.; Keltie, R.F.
1988-12-01
Previous investigations of structural power flow through beam-like structures resulted in some unexplained anomalies in the calculated data. In order to develop structural power flow measurement as a viable technique for machine tool design, the causes of these anomalies needed to be found. Once found, techniques for eliminating the errors could be developed. Error sources were found in the experimental apparatus itself as well as in the instrumentation. Although flexural waves are the carriers of power in the experimental apparatus, at some frequencies longitudinal waves were excited which were picked up by the accelerometers and altered power measurements. Errors were found in the phase and gain response of the sensors and amplifiers used for measurement. A transfer function correction technique was employed to compensate for these instrumentation errors.
Robert Carroll
2007-11-05
We show some relations between Ricci flow and quantum theory via Fisher information and the quantum potential.
Wilms, R Scott; Carlson, Bryan; Coons, James; Kubic, William
2008-01-01
This presentation describes the development of the proposed Process Flow Diagram (PFD) for the Tokamak Exhaust Processing System (TEP) of ITER. A brief review of design efforts leading up to the PFD is followed by a description of the hydrogen-like, air-like, and waterlike processes. Two new design values are described; the mostcommon and most-demanding design values. The proposed PFD is shown to meet specifications under the most-common and mostdemanding design values.
Bellan, Paul M.
to pinch down at the axial midpoint, decreasing the axial variation. The axial magnetic field are with the California Institute of Technology, Pasadena, CA 91125 USA (e-mail: eve@caltech.edu). Digital Object
Microgravity Flow Regime Transition Modeling
Shephard, Adam M.
2010-07-14
Flow regime transitions and the modeling thereof underlie the design of microgravity two-phase systems. Through the use of the zero-g laboratory, microgravity two-phase flows can be studied. Because microgravity two-phase flows exhibit essentially...
Flow regime mapping of vertical two-phase downflow in a ribbed annulus
Kielpinski, A.L.
1992-01-01
Two-phase flow regimes have been mapped for vertical, cocurrent downflow in a narrow annulus which is partially segmented by the presence of longitudinal ribs. This geometry and flow condition has application to the analysis of a Large-Break Loss of Coolant Accident (LB-LOCA) in the production K-Reactor at the Savannah River Site (SRS). The ribbed annular geometry, particularly the presence of non-sealing ribs, gives rise to some unique phenomenological features. The flow behavior is influenced by the partial segmentation of the annulus into four quadrants or subchannels. A random element is induced by the natural bowing of the slender tubes; the width of the azimuthal flow path between two subchannels at a given axial location is indeterminate, and can take on any value between zero and the maximum clearance of 7.6 [times] l0[sup [minus]4] m. When the rib gap is zero at a given location, it is at a maximum 180P away at the same axial location. The range of rib gaps is spanned in a single test section, as it would be also in a reactor assembly. As a result of these effects, flow regime maps obtained by other researchers for downflow in annuli are not accurate for defining flow regimes in a ribbed annulus. Flow regime transitions similar to those noted by, e.g., Bamea, were observed; the locations of these transitions were displaced with respect to the transition equations derived by Bamea. Experimental bubble rise velocity measurements were also obtained in the same test section. The bubble rise velocities were much higher than expected from the theory developed for slug bubbles in tubes, unribbed annuli, and rectangular channels. An elliptical-cap bubble rises faster than a slug bubble of the same area. Large, slug-shaped bubbles injected into the test section were observed to reduce in size as they rose, due to interaction with a longitudinal rib. They thereby adopted a shape more like an elliptical-cap bubble, hence rising faster than the original slug bubble.
Flow regime mapping of vertical two-phase downflow in a ribbed annulus
Kielpinski, A.L.
1992-12-01
Two-phase flow regimes have been mapped for vertical, cocurrent downflow in a narrow annulus which is partially segmented by the presence of longitudinal ribs. This geometry and flow condition has application to the analysis of a Large-Break Loss of Coolant Accident (LB-LOCA) in the production K-Reactor at the Savannah River Site (SRS). The ribbed annular geometry, particularly the presence of non-sealing ribs, gives rise to some unique phenomenological features. The flow behavior is influenced by the partial segmentation of the annulus into four quadrants or subchannels. A random element is induced by the natural bowing of the slender tubes; the width of the azimuthal flow path between two subchannels at a given axial location is indeterminate, and can take on any value between zero and the maximum clearance of 7.6 {times} l0{sup {minus}4} m. When the rib gap is zero at a given location, it is at a maximum 180P away at the same axial location. The range of rib gaps is spanned in a single test section, as it would be also in a reactor assembly. As a result of these effects, flow regime maps obtained by other researchers for downflow in annuli are not accurate for defining flow regimes in a ribbed annulus. Flow regime transitions similar to those noted by, e.g., Bamea, were observed; the locations of these transitions were displaced with respect to the transition equations derived by Bamea. Experimental bubble rise velocity measurements were also obtained in the same test section. The bubble rise velocities were much higher than expected from the theory developed for slug bubbles in tubes, unribbed annuli, and rectangular channels. An elliptical-cap bubble rises faster than a slug bubble of the same area. Large, slug-shaped bubbles injected into the test section were observed to reduce in size as they rose, due to interaction with a longitudinal rib. They thereby adopted a shape more like an elliptical-cap bubble, hence rising faster than the original slug bubble.
Flanagan, C
2006-01-01
O’Callahan and J. -D. Choi. Hybrid dynamic data race detec-subtyping is sound, the hybrid compilation algorithmHybrid Type Checking Cormac Flanagan Department of Computer
Mitroi, F C
2011-01-01
The aim of this paper is to present some new Fejer-type results for convex functions. Improvements of Young's inequality (the arithmetic-geometric mean inequality) and other applications to special means are pointed as well.
Flexure and Axial Compression Loadings. (Under the direction of Dr. Sami Rizkalla.) The use of high in 1999 in Middle East Technical University, Ankara, Turkey. He also received his Master of Science degree of the National Research Council who administered National C
Zhou, Chongwu
interconnecting scheme. Figure S1. Multi-junction solar cells. (a) Multi-junction solar cells consist of materials1 GaAs nanowire array solar cells with axial p-i-n junctions Maoqing Yao, Ningfeng Huang, Sen CongH3 are 7.56×10-7 atm and 2.14×10-4 atm. Solar cells fabrication. Transparent insulating polymer BCB
Shultis, J. Kenneth
2005-01-01
is proposed for determining power-density profiles in nuclear reactor fuel rods from neutron flux measurementsNuclear Instruments and Methods in Physics Research A 547 (2005) 663678 Determining axial fuel-rod power-density profiles from in-core neutron flux measurements J. Kenneth ShultisÃ Department
Berns, Hans-Gerd
MULTILAYER CERAMIC CAPACITORS/AXIAL & RADIAL LEADED KEMET Electronics Corporation, P.O. Box 5928, Greenville, S.C. 29606, (864) 963-6300 KEMET Â® Multilayer ceramic capacitors are available in a variety materials and methods vary depending on the intended use. TEMPERATURE CHARACTERISTICS Ceramic dielectric
Awe, T. J., E-mail: tjawe@sandia.gov; Jennings, C. A.; McBride, R. D.; Cuneo, M. E.; Lamppa, D. C.; Martin, M. R.; Rovang, D. C.; Sinars, D. B.; Slutz, S. A.; Owen, A. C.; Gomez, M. R.; Hansen, S. B.; Herrmann, M. C.; Jones, M. C.; McKenney, J. L.; Robertson, G. K.; Rochau, G. A.; Savage, M. E.; Stygar, W. A. [Sandia National Laboratories, P.O. Box 5800, Albuquerque, New Mexico 87185 (United States)] [Sandia National Laboratories, P.O. Box 5800, Albuquerque, New Mexico 87185 (United States); Tomlinson, K. [General Atomics, San Diego, California 92121 (United States)] [General Atomics, San Diego, California 92121 (United States); and others
2014-05-15
Recent experiments at the Sandia National Laboratories Z Facility have, for the first time, studied the implosion dynamics of magnetized liner inertial fusion (MagLIF) style liners that were pre-imposed with a uniform axial magnetic field. As reported [T. J. Awe et al., Phys. Rev. Lett. 111, 235005 (2013)] when premagnetized with a 7 or 10?T axial field, these liners developed 3D-helix-like hydrodynamic instabilities; such instabilities starkly contrast with the azimuthally correlated magneto-Rayleigh-Taylor (MRT) instabilities that have been consistently observed in many earlier non-premagnetized experiments. The helical structure persisted throughout the implosion, even though the azimuthal drive field greatly exceeded the expected axial field at the liner's outer wall for all but the earliest stages of the experiment. Whether this modified instability structure has practical importance for magneto-inertial fusion concepts depends primarily on whether the modified instability structure is more stable than standard azimuthally correlated MRT instabilities. In this manuscript, we discuss the evolution of the helix-like instability observed on premagnetized liners. While a first principles explanation of this observation remains elusive, recent 3D simulations suggest that if a small amplitude helical perturbation can be seeded on the liner's outer surface, no further influence from the axial field is required for the instability to grow.
Flow Forcing Techniques for Numerical Simulation of Combustion Instabilities
Nicoud, Franck
Flow Forcing Techniques for Numerical Simulation of Combustion Instabilities A. KAUFMANN* and F of combustion instabilities in gas turbine combustors require the knowledge of flame transfer functions. Those flame) and for one case where a CFD code is necessary (a laminar Bunsen-type flame). © 2002
AIAA 2004-4082 Simulation of 3D Flows of
Zha, Gecheng
Flows of Propulsion Systems Using an Efficient Low Diffusion E-CUSP Upwind Scheme Zongjun Hu and Gecheng dissipation. For the scalar dissipation Riemann solver schemes, there are generally two types: H- CUSP schemes is consistent with the characteristic directions.8 The scheme has low diffusion and is able to capture crisp
AN EXPLORATION INTO BATTERY CHEMISTRY IONIC FLOW, INTERCALATION AND
Petta, Jason
AN EXPLORATION INTO BATTERY CHEMISTRY IONIC FLOW, INTERCALATION AND CRYSTAL LATTICES JAKE GARCIA ALLA ZAMARAYEVA ADVISOR: DAN STEINGART #12;A PROBLEM IN SOCIETY! · The energy problem · Batteries-cost and environmentally friendly battery? #12;BACKGROUND · Different Common Battery types: Galvanic "Wet" Cell Dry Cell
Vortices in rotating systems: Centrifugal, elliptic and hyperbolic type instabilities
Lauga, Eric
Vortices in rotating systems: Centrifugal, elliptic and hyperbolic type instabilities D. Sipp, E and centrifugal instabilities. A complete picture of the short-wave stability properties of the flow is given that anticyclones undergo centrifugal instability if the Rossby number verifies Ro 1, elliptic instability for all
Loftus, M.J.; Hochreiter, L.E.; Lee, N.; McGuire, M.F.; Wenzel, A.H.; Valkovic, M.M.
1982-09-01
This report presents data and limited analysis from the 21-Rod Bundle Flow Blockage Task of the Full-Length Emergency Cooling Heat Transfer Separate Effects and Systems Effects Test Program (FLECHT SEASET). The tests consisted of forced and gravity reflooding tests utilizing electrical heater rods with a cosine axial power profile to simulate PWR nuclear core fuel rod arrays. Steam cooling and hydraulic characteristics tests were also conducted. These tests were utilized to determine effects of various flow blockage configurations (shapes and distributions) on reflooding behavior, to aid in development/assessment of computational models in predicting reflooding behavior of flow blockage configurations, and to screen flow blockage configurations for future 163-rod flow blockage bundle tests.
Danko, G.; Birkholzer, J.T.; Bahrami, D.; Halecky, N.
2009-10-01
A coupled thermal-hydrologic-airflow model is developed, solving for the transport processes within a waste emplacement drift and the surrounding rockmass together at the proposed nuclear waste repository at Yucca Mountain. Natural, convective air flow as well as heat and mass transport in a representative emplacement drift during post-closure are explicitly simulated, using the MULTIFLUX model. The conjugate, thermal-hydrologic transport processes in the rockmass are solved with the TOUGH2 porous-media simulator in a coupled way to the in-drift processes. The new simulation results show that large-eddy turbulent flow, as opposed to small-eddy flow, dominate the drift air space for at least 5000 years following waste emplacement. The size of the largest, longitudinal eddy is equal to half of the drift length, providing a strong axial heat and moisture transport mechanism from the hot to the cold drift sections. The in-drift results are compared to those from simplified models using a surrogate, dispersive model with an equivalent dispersion coefficient for heat and moisture transport. Results from the explicit, convective velocity simulation model provide higher axial heat and moisture fluxes than those estimated from the previously published, simpler, equivalent-dispersion models, in addition to showing differences in temperature, humidity and condensation rate distributions along the drift length. A new dispersive model is also formulated, giving a time- and location-variable function that runs generally about ten times higher in value than the highest dispersion coefficient currently used in the Yucca Mountain Project as an estimate for the equivalent dispersion coefficient in the emplacement drift. The new dispersion coefficient variation, back-calculated from the convective model, can adequately describe the heat and mass transport processes in the emplacement drift example.
The effect of anchoring on nematic flow in channels
V. M. O. Batista; M. L. Blow; M. M. Telo da Gama
2015-06-24
Understanding the flow of liquid crystals in microfluidic environments plays an important role in many fields, including device design and microbiology. We perform hybrid lattice-Boltzmann simulations of a nematic liquid crystal flowing under an applied pressure gradient in two-dimensional channels with various anchoring boundary conditions at the substrate walls. We investigate the relation between flow rate and pressure gradient and the corresponding profile of the nematic director, and find significant departures from the linear Poiseuille relation. We also identify a morphological transition in the director profile and explain this in terms of an instability in the dynamical equations. We examine the qualitative and quantitative effects of changing the type and strength of the anchoring. Understanding such effects may provide a useful means of quantifying the anchoring of a substrate by measuring its flow properties.
Modelling complex flood flow evolution in the middle Yellow River basin, China
Yu, Qian
Modelling complex flood flow evolution in the middle Yellow River basin, China Hongming He a January 2008 KEYWORDS Flood routing; Backwater flow; The middle Yellow River; River morphology Summary Flood routing processes in the middle Yellow River basin are complex since they consist of three types
Journal of Power Sources 128 (2004) 5460 Microfluidic fuel cell based on laminar flow
Kenis, Paul J. A.
2004-01-01
Journal of Power Sources 128 (2004) 5460 Microfluidic fuel cell based on laminar flow Eric R compartments. While these PEM-type fuel cell designs have great promise to become the power source of choice a novel microfluidic fuel cell concept that utilizes the occurrence of multi-stream laminar flow
Effect of Flow Field Design and Voltage Change Range on the Dynamic Behavior of PEMFCs
Van Zee, John W.
Effect of Flow Field Design and Voltage Change Range on the Dynamic Behavior of PEMFCs Sunhoe Kim exchange membrane fuel cell PEMFC subjected to rapid changes in the voltage depends on the type of flow that these peak heights are limited primarily by oxygen mass transfer, even though the PEMFC is operating at close
Innovation flow through social networks: Productivity distribution
T. Di Matteo; T. Aste; M. Gallegati
2004-06-19
A detailed empirical analysis of the productivity of non financial firms across several countries and years shows that productivity follows a non-Gaussian distribution with power law tails. We demonstrate that these empirical findings can be interpreted as consequence of a mechanism of exchanges in a social network where firms improve their productivity by direct innovation or/and by imitation of other firm's technological and organizational solutions. The type of network-connectivity determines how fast and how efficiently information can diffuse and how quickly innovation will permeate or behaviors will be imitated. From a model for innovation flow through a complex network we obtain that the expectation values of the productivity level are proportional to the connectivity of the network of links between firms. The comparison with the empirical distributions reveals that such a network must be of a scale-free type with a power-law degree distribution in the large connectivity range.
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity ofkandz-cm11 Outreach Home Room NewsInformation Current HABFES OctoberEvanServices Â»First ObservationFast(ER1)Flow Battery
Fast wire-mesh sensors for gas-liquid flows - Visualisation with up to 10 000 frames per second
Prasser, H.M.; Zschau, J. [Forschungszentrum Rossendorf e.V., P.O.Box 510119, D-01314 Dresden (Germany); Peters, D.; Pietzsch, G.; Taubert, W.; Trepte, M. [Teletronic Ingenieurbuero GmbH, Bautzner Landstrasse 45, D-01454 Grosserkmannsdorf (Germany)
2002-07-01
A wire-mesh sensor developed by the Forschungszentrum Rossendorf produces sequences of instantaneous gas fraction distributions in a cross section at a rate of up to 10 000 frames per second and a spatial resolution of about 2-3 mm. This sensor was applied to an upwards air-liquid flow in a vertical pipe of 51.2 mm diameter. After a brief introduction of the functioning of the sensor, the paper presents results obtained in a at vertical pipe operated with an air-water mixture. Two wire-mesh sensors with a measuring matrix of 24 x 24 points (resolution 2 mm) were placed in a small axial distance behind each other. They were used to study the flow structure in the transition region from bubble to slug flow at an imaging frequency of 2 500 Hz. The two available measuring planes allowed to obtain velocity profiles of the gaseous phase. A sensor with 16 x 16 points (resolution 3 mm) was applied to visualize the transition from bubbly via churn turbulent to annular flow with 10 000 frames per second. In the churn flow region, periodic plug-like structures were found. In the annular flow the sensor is able to resolve wispy structures. (authors)
Pipeline failure: The roles played by corrosion, flow and metallurgy
Paisley, D.; Barrett, N.; Wilson, O.
1999-11-01
Carbon dioxide corrosion has been widely studied in the field and laboratory. It is recognized that flow regime and metallurgy are important factors that influence in-situ corrosion rates but there are relatively few documented case studies that are able to separate the individual contributions of corrosion, flow regime and metallurgy on the observed corrosion damage. This paper deals with failure of a pipeline where high quality inspection data together with comprehensive as-built records and stable production conditions allowed the separate influences of flow and metallurgy on corrosion to be studied. The flow regimes in the pipeline ranged from low velocity, stratified flow to high velocity, slug flow. The inspection data showed that the affect of turbulent flow was to increase the frequency of corrosion pits and, in the case of weld corrosion, the mean corrosion rate. The pipeline was constructed from two grades of steel and welded using two types of welding consumable. One grade of pipeline steel corroded at a significantly higher rate and with a higher frequency of corrosion pits than another, apparently similar steel. However, no significant relationship was found between weld metallurgy and corrosion rate or frequency.
Studies of vertical annular gas-liquid flows
Zabaras, G.J.
1985-01-01
Three types of vertical flowing films were studied. These are the free falling film, the falling film in the presence of countercurrent gas flow, and the upward moving film due to concurrent flow of gas. An experimental program was performed based on a new electrochemical method for the dynamic measurement of the magnitude and the direction of the wall shear stress, and on a conductance wire probe for the simultaneous measurement of the film thickness. Pressure drop was measured over a short distance with a differential pressure transducer. The data obtained for the free falling film reveal a strong length effect on the wavy-film structure. The measured variation of the wall shear stress along a wave suggests that a mixing vortex exists in the wave front followed by the development of a hydrodynamic boundary layer in the wave back. Analysis of the data taken with counter current flow of gas shows that even at the flooding condition, the film flow is controlled by downward wave motion. Measured wall shear stress was found to be upward directed and decreasing in magnitude with increasing gas rate. Analyses of the upward film flow data in a variety of ways suggest that, at low gas rates, the motion of the interface is controlled by a process of switching between possible steady states of the system. This condition is usually designated as churn flow but bridging of the liquid across the pipe as associated with churning does not occur.
Spiral Laminar Flow: A revolution in understanding?
Greenaway, Alan
Blood Flow Spiral laminar flow #12;Spiral flow in the Aorta (MRI) Computational Fluid Dynamics 0 10 20Spiral Laminar Flow: A revolution in understanding? Reintroduction of natural blood flow Laminar Flow through Runoff (3months) Proximal Anastomosis SLF TM Graft Distal Anastomosis Post-op Angios
Valenzuela, Javier (Hanover, NH)
2001-01-01
A radial flow heat exchanger (20) having a plurality of first passages (24) for transporting a first fluid (25) and a plurality of second passages (26) for transporting a second fluid (27). The first and second passages are arranged in stacked, alternating relationship, are separated from one another by relatively thin plates (30) and (32), and surround a central axis (22). The thickness of the first and second passages are selected so that the first and second fluids, respectively, are transported with laminar flow through the passages. To enhance thermal energy transfer between first and second passages, the latter are arranged so each first passage is in thermal communication with an associated second passage along substantially its entire length, and vice versa with respect to the second passages. The heat exchangers may be stacked to achieve a modular heat exchange assembly (300). Certain heat exchangers in the assembly may be designed slightly differently than other heat exchangers to address changes in fluid properties during transport through the heat exchanger, so as to enhance overall thermal effectiveness of the assembly.
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity ofkandz-cm11 Outreach Home RoomPreservationBio-Inspired SolarAbout /Two Electron Holes in HematiteType Ia Supernovae Type Ia
National Nuclear Security Administration (NNSA)
AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity of NaturalDukeWakefield Municipal Gas &SCE-SessionsSouthReporteeo | National Nucleara min [Type the abstract of theType
Crenshaw, Michael
to nuclear fusion. · Novae radiate primarily in the UV to X-ray region. · Types: Classical Novae: only one is hot enough for explosive fusion. For classical novae, this happens on a time scale of 103 105 years. · Thermonuclear runaway (TNR): capture of protons by heavy elements (CNO cycle), happens in seconds #12;5 Novae
Active combustion flow modulation valve
Hensel, John Peter; Black, Nathaniel; Thorton, Jimmy Dean; Vipperman, Jeffrey Stuart; Lambeth, David N; Clark, William W
2013-09-24
A flow modulation valve has a slidably translating hollow armature with at least one energizable coil wound around and fixably attached to the hollow armature. The energizable coil or coils are influenced by at least one permanent magnet surrounding the hollow armature and supported by an outer casing. Lorentz forces on the energizable coils which are translated to the hollow armature, increase or decrease the flow area to provide flow throttling action. The extent of hollow armature translation depends on the value of current supplied and the direction of translation depends on the direction of current flow. The compact nature of the flow modulation valve combined with the high forces afforded by the actuator design provide a flow modulation valve which is highly responsive to high-rate input control signals.
Drains Debubbler Transport Liq. Flow
Weber, Rodney
Drains Debubbler Transport Liq. Flow (LiF) aq. Anion Cation Waste Vacuum Pump LiF H2 O Pure H2 O 1 Denuders Cyclon 16 L/min 2.5 µm cut Sample Tubing ColourFlow, mL/minTubing green/green-1 green/green-2, and Liquid Flow Rates Are Possible Cation: metrosep 2100B-100x4.0mm Eluent: 0.250g/L Dipicolinic acid 1000 u
Magneto-Centrifugal Launching of Jets from Accretion Disks; 1, Cold Axisymmetric Flows
Krasnopolsky, R; Blandford, R D
1999-01-01
The magneto-centrifugal model for jet formation is studied by time-dependent simulations reaching steady state in a cold gas with negligible fluid pressure, in an axisymmetric geometry, using a modification of the Zeus3D code adapted to parallel computers. The number of boundary conditions imposed at the coronal base takes into account the existence of the fast and Alfvenic critical surfaces, avoiding over-determination of the flow. The size and shape of the computational box is chosen to include these critical surfaces, reducing the influence of the outer boundary conditions. As there is a region, near the origin, where the inclination of field lines to the axis is too small to drive a centrifugal wind, we inject a thin, axial jet, expected to form electromagnetically near black holes. Acceleration and collimation appear for wide generic conditions. A reference run is shown in detail, with a wind leaving the computational volume in the axial direction with a poloidal velocity equal to 4 times the poloidal Al...
Magneto-Centrifugal Launching of Jets from Accretion Disks. I: Cold Axisymmetric Flows
R. Krasnopolsky; Z. -Y. Li; R. D. Blandford
1999-07-29
The magneto-centrifugal model for jet formation is studied by time-dependent simulations reaching steady state in a cold gas with negligible fluid pressure, in an axisymmetric geometry, using a modification of the Zeus3D code adapted to parallel computers. The number of boundary conditions imposed at the coronal base takes into account the existence of the fast and Alfvenic critical surfaces, avoiding over-determination of the flow. The size and shape of the computational box is chosen to include these critical surfaces, reducing the influence of the outer boundary conditions. As there is a region, near the origin, where the inclination of field lines to the axis is too small to drive a centrifugal wind, we inject a thin, axial jet, expected to form electromagnetically near black holes. Acceleration and collimation appear for wide generic conditions. A reference run is shown in detail, with a wind leaving the computational volume in the axial direction with a poloidal velocity equal to 4 times the poloidal Alfven speed, collimated inside 11 degrees. Finally, the critical surfaces, fieldlines, thrust, energy, torque and mass discharge of the outgoing wind are shown for simulations with various profiles of mass and magnetic flux at the base of the corona.
Elliptic Flow at Large Viscosity
Volker Koch
2009-09-18
In this contribution we present an alternative scenario for the large elliptic flow observed in relativistic heavy ion collisions. Motivated by recent results from Lattice QCD on flavor off-diagonal susceptibilities we argue that the matter right above $T_{c}$ can be described by single-particle dynamics in a repulsive single-particle potential, which in turn gives rise to elliptic flow. These ideas can be tested experimentally by measuring elliptic flow of heavy quarks, preferably via the measurement of $J/\\Psi$ elliptic flow.
Torczynski, John R. (Albuquerque, NM)
2001-02-27
A module bay requires less cleanroom airflow. A shaped gas inlet passage can allow cleanroom air into the module bay with flow velocity preferentially directed toward contaminant rich portions of a processing module in the module bay. Preferential gas flow direction can more efficiently purge contaminants from appropriate portions of the module bay, allowing a reduced cleanroom air flow rate for contaminant removal. A shelf extending from an air inlet slit in one wall of a module bay can direct air flowing therethrough toward contaminant-rich portions of the module bay, such as a junction between a lid and base of a processing module.
DOE Data Explorer [Office of Scientific and Technical Information (OSTI)]
Nicole Lautze
2015-01-01
Groundwater flow model for Kauai. Data is from the following sources: Whittier, R. and A.I. El-Kadi. 2014. Human and Environmental Risk Ranking of Onsite Sewage Disposal Systems For the Hawaiian Islands of Kauai, Molokai, Maui, and Hawaii – Final. Prepared by the University of Hawaii, Dept. of Geology and Geophysics for the State of Hawaii Dept. of Health, Safe Drinking Water Branch. September 2014.; and Whittier, R.B., K. Rotzoll, S. Dhal, A.I. El-Kadi, C. Ray, G. Chen, and D. Chang. 2004. Hawaii Source Water Assessment Program Report – Volume IV – Island of Kauai Source Water Assessment Program Report. Prepared for the Hawaii Department of Health, Safe Drinking Water Branch. University of Hawaii, Water Resources Research Center. Updated 2015.
Broader source: Energy.gov [DOE]
Learn about the standard page types available in the Energy.gov Drupal content management system. For information about other available page types, or to request a new kind of page type, contact...
Practical pluggable types for Java
Papi, Matthew M
2008-01-01
This paper introduces the Checker Framework, which supports adding pluggable type systems to the Java language in a backward-compatible way. A type system designer defines type qualifiers and their semantics, and a compiler ...
Window Types | Department of Energy
Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site
aluminum or vinyl cladding reduces maintenance requirements. Types of Window Glazing or Glass In addition to choosing a frame type, you will need to consider what type of glazing...
Non--Atomic Components of Data Flow Diagrams: Stores, Persistent Flows,
Symanzik, Jürgen
Non--Atomic Components of Data Flow Diagrams: Stores, Persistent Flows, and Tests for Empty Flows J NON--ATOMIC COMPONENTS OF DATA FLOW DIAGRAMS: STORES, PERSISTENT FLOWS, AND TESTS FOR EMPTY FLOWS of these common features of traditional Data Flow Diagrams elevates the expressive power of FDFD's, or whether
Event-shape fluctuations and flow correlations in ultra-relativistic heavy-ion collisions
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
Jia, Jiangyong
2014-12-01
I review recent measurements of a large set of flow observables associated with event-shape fluctuations and collective expansion in heavy ion collisions. First, these flow observables are classified and experiment methods are introduced. The experimental results for each type of observables are then presented and compared to theoretical calculations. A coherent picture of initial condition and collective flow based on linear and non-linear hydrodynamic responses is derived, which qualitatively describe most experimental results. I discuss new types of fluctuation measurements that can further our understanding of the event-shape fluctuations and collective expansion dynamics.
Dust around Type Ia supernovae
Wang, Lifan
2005-01-01
Dust around Type Ia supernovae Lifan Wang 1,2 LawrenceIa. Subject headings: Supernovae: General, Dust, Extinctionline) bands for Type Ia supernovae. (a), upper panel, shows
Mohsenpour, Taghi; Mehrabi, Narges [Department of Physics, Faculty of Basic Sciences, University of Mazandaran, Babolsar (Iran, Islamic Republic of)] [Department of Physics, Faculty of Basic Sciences, University of Mazandaran, Babolsar (Iran, Islamic Republic of)
2013-08-15
The dispersion relation of a two-stream free-electron laser (TSFEL) with a one-dimensional helical wiggler and an axial magnetic field is studied. Also, all relativistic effects on the space-charge wave and radiation are considered. This dispersion relation is solved numerically to find the unstable interaction among the all wave modes. Numerical calculations show that the growth rate is considerably enhanced in comparison with single-stream FEL. The effect of the velocity difference of the two electron beams on the two-stream instability and the FEL resonance is investigated. The maximum growth rate of FEL resonance is investigated numerically as a function of the axial magnetic field.
Pidcoe, Stephen V. (Bonita, CA); Zink, Roger A. (Desoto, TX); Boroski, William N. (Aurora, IL); McCaw, William R. (Burr Ridge, IL)
1993-01-01
An arrangement for measuring the field angle of a magnetic field as a function of axial position within a magnet bore tube of a magnet such as is used with the Superconducting Super Collider (SSC). The arrangement includes a magnetic field alignment gauge that is carried through the magnet bore tube by a positioning shuttle in predetermined increments. The positioning shuttle includes an extensible body assembly which is actuated by an internal piston arrangement. A pair of spaced inflatable cuffs are carried by the body assembly and are selectively actuated in cooperation with pressurizing of the piston to selectively drive the positioning shuttle in an axial direction. Control of the shuttle is provided by programmed electronic computer means located exteriorly of the bore tube and which controls valves provided pressurized fluid to the inflatable cuss and the piston arrangement.
Abdelfattah, Sherif Alykadry
2013-08-07
(RANS) and Unsteady (URANS) Analyses . . . . . . . . . . 66 7.2 Analysis of Numerical Results . . . . . . . . . . . . . . . . . . . . . . . . . . 70 7.2.1 Seal Leakage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 71 7.2.2 Flow... constants. . . . . . . 162 10.3 Intermittency correlation constants, as listed in Chakka and Schobeiri [53]. 169 10.4 Unsteady plate boundary conditions. . . . . . . . . . . . . . . . . . . . . . 179 10.5 Blade cascade boundary condition for RANS...
Redox Flow Batteries, a Review
U. Tennessee Knoxville; U. Texas Austin; McGill U; Weber, Adam Z.; Mench, Matthew M.; Meyers, Jeremy P.; Ross, Philip N.; Gostick, Jeffrey T.; Liu, Qinghua
2011-07-15
Redox flow batteries are enjoying a renaissance due to their ability to store large amounts of electrical energy relatively cheaply and efficiently. In this review, we examine the components of redox flow batteries with a focus on understanding the underlying physical processes. The various transport and kinetic phenomena are discussed along with the most common redox couples.
Mean Curvature Driven Ricci Flow
Victor Tapia
2009-03-11
We obtain the evolution equations for the Riemann tensor, the Ricci tensor and the scalar curvature induced by the mean curvature flow. The evolution for the scalar curvature is similar to the Ricci flow, however, negative, rather than positive, curvature is preserved. Our results are valid in any dimension.
FLOW CONDITIONING DESIGN IN TURBULENT
California at San Diego, University of
, or liquid sheets, create protective pocket to shield chamber side walls · Lattice of stationary sheets shield front/back walls while allowing beam propagation and target injection (High-Yield Lithium conditioner configurations #12;5 Flow Loop A Pump H 400 gal tank B Bypass line I Butterfly valve C Flow meter
Network Flow Optimization under Uncertainty
Tesfatsion, Leigh
, production, generation, transportation, trade, storage injections and withdrawals of coal, gas?) xij is flow along arc (i, j), from node i to node j cij is cost per unit of flow along (i, j Network model in words Minimize the cost of satisfying demands for electric energy By: imports, exports
Optimized boundary driven flows for dynamos in a sphere
Khalzov, I. V.; Brown, B. P.; Cooper, C. M.; Weisberg, D. B.; Forest, C. B. [Center for Magnetic Self Organization in Laboratory and Astrophysical Plasmas, University of Wisconsin-Madison, 1150 University Avenue, Madison, Wisconsin 53706 (United States)
2012-11-15
We perform numerical optimization of the axisymmetric flows in a sphere to minimize the critical magnetic Reynolds number Rm{sub cr} required for dynamo onset. The optimization is done for the class of laminar incompressible flows of von Karman type satisfying the steady-state Navier-Stokes equation. Such flows are determined by equatorially antisymmetric profiles of driving azimuthal (toroidal) velocity specified at the spherical boundary. The model is relevant to the Madison plasma dynamo experiment, whose spherical boundary is capable of differential driving of plasma in the azimuthal direction. We show that the dynamo onset in this system depends strongly on details of the driving velocity profile and the fluid Reynolds number Re. It is found that the overall lowest Rm{sub cr} Almost-Equal-To 200 is achieved at Re Almost-Equal-To 240 for the flow, which is hydrodynamically marginally stable. We also show that the optimized flows can sustain dynamos only in the range Rm{sub cr}
Opposed-flow virtual cyclone for particle concentration
Rader, Daniel J. (Lafayette, CA); Torczynski, John R. (Albuquerque, NM)
2000-12-05
An opposed-flow virtual cyclone for aerosol collation which can accurately collect, classify, and concentrate (enrich) particles in a specific size range. The opposed-flow virtual cyclone is a variation on the virtual cyclone and has its inherent advantages (no-impact particle separation in a simple geometry), while providing a more robust design for concentrating particles in a flow-through type system. The opposed-flow virtual cyclone consists of two geometrically similar virtual cyclones arranged such that their inlet jets are inwardly directed and symmetrically opposed relative to a plane of symmetry located between the two inlet slits. A top plate bounds both jets on the "top" side of the inlets, while the other or lower wall curves "down" and away from each inlet jet. Each inlet jet will follow the adjacent lower wall as it turns away, and that particles will be transferred away from the wall and towards the symmetry plane by centrifugal action. After turning, the two jets merge smoothly along the symmetry line and flow parallel to it through the throat. Particles are transferred from the main flows, across a dividing streamline, and into a central recirculating region, where particle concentrations become greatly increased relative to the main stream.
Huang, J Q; Wu, C F; Zhang, J W; Feng, Y Y; Wang, L J
2015-01-01
We report our studies on an intense source of cold cesium atoms based on a two-dimensional magneto-optical trap with independent axial cooling and pushing. The new-designed source, proposed as 2D-HP MOT, uses hollow laser beams for axial cooling and a thin pushing laser beam for cold atomic beam extraction. Regulated independently by the pushing beam, the atomic flux can be substantially optimized. The atomic flux maximum obtained in the 2D-HP MOT is $4.02\\times 10^{10}$ atoms/s, increased by 60 percent compared to the traditional 2D$^+$ MOT in our experiment. Moreover, with the pushing power 10 $\\mu$W and detuning $0\\Gamma$, the 2D-HP MOT can generate a rather intense cold cesium atomic beam with the concomitant light shift suppressed by 20 times in magnitude. The axial velocity distribution of the cold cesium beams centers at 6.8 m/s with a FMHW of about 2.8 m/s. The dependences of the atomic flux on the pushing power and detuning are studied. The experimental results are in good agreement with the theoreti...
Electromigration dispersion in a capillary in the presence of electro-osmotic flow
Ghosal, S
2012-01-01
The differential migration of ions in an applied electric field is the basis for separation of chemical species by capillary electrophoresis. Axial diffusion of the concentration peak limits the separation efficiency. Electromigration dispersion is observed when the concentration of sample ions is comparable to that of the background ions. Under such conditions, the local electrical conductivity is significantly altered in the sample zone making the electric field, and therefore, the ion migration velocity concentration dependent. The resulting nonlinear wave exhibits shock like features, and, under certain simplifying assumptions, is described by Burgers' equation (S. Ghosal and Z. Chen Bull. Math. Biol. 2010, vol.72, pg. 2047).In this paper, we consider the more general situation where the walls of the separation channel may have a non-zero zeta potential and are therefore able to sustain an electro-osmotic bulk flow. The main result is a one dimensional nonlinear advection diffusion equation for the area a...
Dynamic and spectroscopic characteristics of atmospheric gliding arc in gas-liquid two-phase flow
Tu, X.; Yu, L.; Yan, J. H.; Cen, K. F.; Cheron, B. G.
2009-11-15
In this study, an atmospheric alternating-current gliding arc device in gas-liquid two-phase flow has been developed for the purpose of waste water degradation. The dynamic behavior of the gas-liquid gliding arc is investigated through the oscillations of electrical signals, while the spatial evolution of the arc column is analyzed by high speed photography. Different arc breakdown regimes are reported, and the restrike mode is identified as the typical fluctuation characteristic of the hybrid gliding arc in air-water mixture. Optical emission spectroscopy is employed to investigate the active species generated in the gas-liquid plasma. The axial evolution of the OH (309 nm) intensity is determined, while the rotational and vibrational temperatures of the OH are obtained by a comparison between the experimental and simulated spectra. The significant discrepancy between the rotational and translational temperatures has also been discussed.
Vertical flow chemical detection portal
Linker, Kevin L. (Albuquerque, NM); Hannum, David W. (Albuquerque, NM); Conrad, Frank James (Russellville, SC)
1999-01-01
A portal apparatus for screening objects or persons for the presence of trace amounts of chemical substances such as illicit drugs or explosives. The apparatus has a test space, in which a person may stand, defined by two generally upright sides spanned by a horizontal transom. One or more fans in the transom generate a downward air flow (uni-directional) within the test space. The air flows downwardly from a high pressure upper zone, past the object or person to be screened. Air moving past the object dislodges from the surface thereof both volatile and nonvolatile particles of the target substance. The particles are entrained into the air flow which continues flowing downward to a lower zone of reduced pressure, where the particle-bearing air stream is directed out of the test space and toward preconcentrator and detection components. The sides of the portal are specially configured to partially contain and maintain the air flow.
Vertical flow chemical detection portal
Linker, K.L.; Hannum, D.W.; Conrad, F.J.
1999-06-22
A portal apparatus is described for screening objects or persons for the presence of trace amounts of chemical substances such as illicit drugs or explosives. The apparatus has a test space, in which a person may stand, defined by two generally upright sides spanned by a horizontal transom. One or more fans in the transom generate a downward air flow (uni-directional) within the test space. The air flows downwardly from a high pressure upper zone, past the object or person to be screened. Air moving past the object dislodges from the surface thereof both volatile and nonvolatile particles of the target substance. The particles are entrained into the air flow which continues flowing downward to a lower zone of reduced pressure, where the particle-bearing air stream is directed out of the test space and toward preconcentrator and detection components. The sides of the portal are specially configured to partially contain and maintain the air flow. 3 figs.
Recurrent flow analysis in spatiotemporally chaotic 2-dimensional Kolmogorov flow
Dan Lucas; Rich Kerswell
2015-04-01
Motivated by recent success in the dynamical systems approach to transitional flow, we study the efficiency and effectiveness of extracting simple invariant sets (recurrent flows) directly from chaotic/turbulent flows and the potential of these sets for providing predictions of certain statistics of the flow. Two-dimensional Kolmogorov flow (the 2D Navier-Stokes equations with a sinusoidal body force) is studied both over a square [0, 2{\\pi}]2 torus and a rectangular torus extended in the forcing direction. In the former case, an order of magnitude more recurrent flows are found than previously (Chandler & Kerswell 2013) and shown to give improved predictions for the dissipation and energy pdfs of the chaos via periodic orbit theory. Over the extended torus at low forcing amplitudes, some extracted states mimick the statistics of the spatially-localised chaos present surprisingly well recalling the striking finding of Kawahara & Kida (2001) in low-Reynolds-number plane Couette flow. At higher forcing amplitudes, however, success is limited highlighting the increased dimensionality of the chaos and the need for larger data sets. Algorithmic developments to improve the extraction procedure are discussed.
Wavy flow cooling concept for turbine airfoils
Liang, George (Palm City, FL)
2010-08-31
An airfoil including an outer wall and a cooling cavity formed therein. The cooling cavity includes a leading edge flow channel located adjacent a leading edge of the airfoil and a trailing edge flow channel located adjacent a trailing edge of the airfoil. Each of the leading edge and trailing edge flow channels define respective first and second flow axes located between pressure and suction sides of the airfoil. A plurality of rib members are located within each of the flow channels, spaced along the flow axes, and alternately extending from opposing sides of the flow channels to define undulating flow paths through the flow channels.
HYPERBOLIC SYSTEMS OF THREE-PHASE FLOW
Patzek, Tadeusz W.
HYPERBOLIC SYSTEMS OF THREE-PHASE FLOW IN POROUS MEDIA Gordon Conference on Flow and Transport SINTEF IKT, Dept. Applied Mathematics, Norway #12;2 WHY THREE-PHASE FLOW + Three-phase flow is the rule: ! Exceptionally accurate, fast numerical solutions to realistic three-phase flows in porous media + Approach
Mathematical Model Analysis for Hg Flow
McDonald, Kirk
Mathematical Model Analysis for Hg Flow Yan Zhan SUNYSB April 20th, 2010 #12;Outline · Introduction Mechanism of Jet Breakup & Atomization Dynamic Problems in Hg Target Flow · Mathematical Model for Hg Flow Parameters Incompressible Flow (No MHD) Incompressible Flow (MHD) Proton Beam Energy Conversion
Electromigration dispersion in a capillary in the presence of electro-osmotic flow
S. Ghosal; Z. Chen
2012-03-08
The differential migration of ions in an applied electric field is the basis for separation of chemical species by capillary electrophoresis. Axial diffusion of the concentration peak limits the separation efficiency. Electromigration dispersion is observed when the concentration of sample ions is comparable to that of the background ions. Under such conditions, the local electrical conductivity is significantly altered in the sample zone making the electric field, and therefore, the ion migration velocity concentration dependent. The resulting nonlinear wave exhibits shock like features, and, under certain simplifying assumptions, is described by Burgers' equation (S. Ghosal and Z. Chen Bull. Math. Biol. 2010, vol.72, pg. 2047).In this paper, we consider the more general situation where the walls of the separation channel may have a non-zero zeta potential and are therefore able to sustain an electro-osmotic bulk flow. The main result is a one dimensional nonlinear advection diffusion equation for the area averaged concentration. This homogenized equation accounts for the Taylor-Aris dispersion resulting from the variation in the electro-osmotic slip velocity along the wall. It is shown that in a certain range of parameters, the electro-osmotic flow can actually reduce the total dispersion by delaying the formation of a concentration shock. However, if the electro-osmotic flow is sufficiently high, the total dispersion is increased because of the Taylor-Aris contribution.
Wall pressure measurements of flooding in vertical countercurrent annular air–water flow
Choutapalli, I., Vierow, K.
2010-01-01
An experimental study of flooding in countercurrent air-water annular flow in a large diameter vertical tube using wall pressure measurements is described in this paper. Axial pressure profiles along the length of the test section were measured up to and after flooding using fast response pressure transducers for three representative liquid flow rates representing a wide range of liquid Reynolds numbers (ReL = 4?/?; ? is the liquid mass flow rate per unit perimeter; ? is the dynamic viscosity) from 3341 to 19,048. The results show that flooding in large diameter tubes cannot be initiated near the air outlet and is only initiated near the air inlet. Fourier analysis of the wall pressure measurements shows that up to the point of flooding, there is no dominant wave frequency but rather a band of frequencies encompassing both the low frequency and the broad band that are responsible for flooding. The data indicates that flooding in large diameter vertical tubes may be caused by the constructive superposition of a plurality of waves rather than the action of a single large-amplitude wave.
Turbine blade tip flow discouragers
Bunker, Ronald Scott (Niskayuna, NY)
2000-01-01
A turbine assembly comprises a plurality of rotating blade portions in a spaced relation with a stationery shroud. The rotating blade portions comprise a root section, a tip portion and an airfoil. The tip portion has a pressure side wall and a suction side wall. A number of flow discouragers are disposed on the blade tip portion. In one embodiment, the flow discouragers extend circumferentially from the pressure side wall to the suction side wall so as to be aligned generally parallel to the direction of rotation. In an alternative embodiment, the flow discouragers extend circumferentially from the pressure side wall to the suction side wall so as to be aligned at an angle in the range between about 0.degree. to about 60.degree. with respect to a reference axis aligned generally parallel to the direction of rotation. The flow discouragers increase the flow resistance and thus reduce the flow of hot gas flow leakage for a given pressure differential across the blade tip portion so as to improve overall turbine efficiency.
The transition from two phase bubble flow to slug flow
Radovcich, Nick A.
1962-01-01
The process of transition from bubble to slug flow in a vertical pipe has been studied analytically and experimentally. An equation is presented which gives the agglomeration time as a function of void fraction, channel ...
Hassanein, Ahmed (Bolingbrook, IL); Konkashbaev, Isak (Bolingbrook, IL)
2006-10-03
A device and method for generating extremely short-wave ultraviolet electromagnetic wave uses two intersecting plasma beams generated by two plasma accelerators. The intersection of the two plasma beams emits electromagnetic radiation and in particular radiation in the extreme ultraviolet wavelength. In the preferred orientation two axially aligned counter streaming plasmas collide to produce an intense source of electromagnetic radiation at the 13.5 nm wavelength. The Mather type plasma accelerators can utilize tin, or lithium covered electrodes. Tin, lithium or xenon can be used as the photon emitting gas source.
Oak Ridge National Laboratory
(r, x = 0) = To(t) (9) At r = r0, To(t) is a known function of time t that represents the heat pump operation. For a given heat pump, if we know the fluid h(T, - Tf) = K TP (4) inlet temperature and flow rate the manufacturer's published heat pump performance At r = r, in winter: data. The heat pump exit fluid represents
Surfactant-driven flow transitions in evaporating droplets
Marin, Alvaro; Rossi, Massimiliano; Kähler, Christian J
2015-01-01
An evaporating droplet is a dynamic system in which flow is spontaneously generated to minimize the surface energy, dragging particles to the borders and ultimately resulting in the so-called "coffee-stain effect". The situation becomes more complex at the droplet's surface, where surface tension gradients of different nature can compete with each other yielding different scenarios. With careful experiments and with the aid of 3D particle tracking techniques, we are able to show that different types of surfactants turn the droplet's surface either rigid or elastic, which alters the evaporating fluid flow, either enhancing the classical coffee-stain effect or leading to a total flow inversion. Our measurements lead to unprecedented and detailed measurements of the surface tension difference along an evaporating droplet's surface with good temporal and spatial resolution.
Speed-up of combustion fronts in shear flows
Hamel, Francois
2011-01-01
This paper is concerned with the analysis of speed-up of reaction-diffusion-advection traveling fronts in infinite cylinders with periodic boundary conditions. The advection is a shear flow with a large amplitude and the reaction is nonnegative, with either positive or zero ignition temperature. The unique or minimal speeds of the traveling fronts are proved to be asymptotically linear in the flow amplitude as the latter goes to infinity, solving an open problem from \\cite{b}. The asymptotic growth rate is characterized explicitly as the unique or minimal speed of traveling fronts for a limiting degenerate problem, and the convergence of the regular traveling fronts to the degenerate ones is proved for positive ignition temperatures under an additional H{\\"{o}}rmander-type condition on the flow.
Park, Sang
2010-01-16
Conventionally the size of the back clearance played a great importance on reducing the axial clearance by utilizing the concept that the decreased axial clearance results in lower axial force acting on the impeller. ...
Dieter Van den Bleeken
2012-02-03
We revisit BPS solutions to classical N=2 low energy effective gauge theories. It is shown that the BPS equations can be solved in full generality by the introduction of a Hesse potential, a symplectic analog of the holomorphic prepotential. We explain how for non-spherically symmetric, non-mutually local solutions, the notion of attractor flow generalizes to gradient flow with respect to the Hesse potential. Furthermore we show that in general there is a non-trivial magnetic complement to this flow equation that is sourced by the momentum current in the solution.
Transient eddy current flow metering
Forbriger, Jan
2015-01-01
Measuring local velocities or entire flow rates in liquid metals or semiconductor melts is a notorious problem in many industrial applications, including metal casting and silicon crystal growth. We present a new variant of an old technique which relies on the continuous tracking of a flow-advected transient eddy current that is induced by a pulsed external magnetic field. This calibration-free method is validated by applying it to the velocity of a spinning disk made of aluminum. First tests at a rig with a flow of liquid GaInSn are also presented.