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Title: Airborne plume dispersion from two-dimensional computational hydrodynamic simulations

Publication Date:
Research Org.:
Massachusetts Inst. of Tech., Cambridge
OSTI Identifier:
Report Number(s):
Journal ID: CODEN: TANSA; TRN: 80-012245
Resource Type:
Resource Relation:
Journal Name: Trans. Am. Nucl. Soc.; (United States); Journal Volume: 33; Conference: American Nuclear Society meeting, San Francisco, CA, USA, 12 Nov 1979
Country of Publication:
United States
20 FOSSIL-FUELED POWER PLANTS; 54 ENVIRONMENTAL SCIENCES; PLUMES; ATMOSPHERIC CHEMISTRY; MATHEMATICAL MODELS; HYDRODYNAMICS; RADIOACTIVE EFFLUENTS; THERMAL EFFLUENTS; CHEMISTRY; FLUID MECHANICS; MECHANICS; RADIOACTIVE MATERIALS; RADIOACTIVE WASTES; WASTES; 200202* - Fossil-Fueled Power Plants- Waste Management- Noxious Gas & Particulate Emissions; 500300 - Environment, Atmospheric- Radioactive Materials Monitoring & Transport- (-1989); 500400 - Environment, Atmospheric- Thermal Effluents Monitoring & Transport- (-1989)

Citation Formats

Bennett, R.G., and Golay, M.W. Airborne plume dispersion from two-dimensional computational hydrodynamic simulations. United States: N. p., 1979. Web.
Bennett, R.G., & Golay, M.W. Airborne plume dispersion from two-dimensional computational hydrodynamic simulations. United States.
Bennett, R.G., and Golay, M.W. 1979. "Airborne plume dispersion from two-dimensional computational hydrodynamic simulations". United States. doi:.
title = {Airborne plume dispersion from two-dimensional computational hydrodynamic simulations},
author = {Bennett, R.G. and Golay, M.W.},
abstractNote = {},
doi = {},
journal = {Trans. Am. Nucl. Soc.; (United States)},
number = ,
volume = 33,
place = {United States},
year = 1979,
month = 1

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  • Computational fluid dynamics (CFD) can be used to solve environmental problems caused by heat and contaminant dispersion from process plants. CFD is a CAD-based software tool, which provides profiles of local fluid velocity, fluid temperature and species concentrations. CFD has enabled engineers to identify solutions to problems quickly without resorting to traditional experimental approaches. In this paper, three actual projects are described which demonstrate the utility of CFD to dispersion modeling and the increasing level of sophistication with which it has been applied. In some cases experimental tests or actual field operation provide sources of model validation and verification. Inmore » the first case, CFD models of tankhouse ventilation systems, based on three South American projects, were developed to guide the selection of equipment for crossflow ventilation systems to meet workplace air quality requirements. In the course of this study, it was found that significant quantities of recirculation could occur for moderate wind conditions opposite to the fan exhaust. In the second case, CFD models were developed to simulate the fluid dynamics of the buoyant plume released during a copper smelter charging operation and to investigate plume collection system designs. Side skirt and canopy configurations were demonstrated to be key design parameters for plume capture. Although not initially expected, a simplified design configuration was found to achieve maximum plume capture, which was later confirmed in actual operation. In the third case, heat recirculation from LNG Plants was investigated. In a liquefied natural gas (LNG) plant in the Caribbean, it was recognized that wind-induced recirculation of the turbine and condenser exhaust could negatively impact operating margins. Dispersion characteristics for the entire plant were simulated using detailed CFD models to predict the temperature profiles entering the coolers under various wind directions and speeds.« less
  • A 3D computational fluid dynamics study using Reynolds averaged Navier-Stokes modeling was conducted and validated with field data from the Joint Urban 2003 dispersion study in Oklahoma City. The modeled flow field indicated that the many short buildings in this domain had a relatively small effect on the flow field, while the few tall buildings drove the transport and dispersion of tracer gas through the domain. Modeled concentrations and wind speeds were compared to observations along a vertical profile located about 500 meters downwind of the source. The isothermal base case using the k-epsilon closure model was within 50% ofmore » the field measurements, while a convective case with ground and building surfaces 10 degrees C hotter than ambient temperatures improved the modeled profile to within 30% of observations. Varying wind direction and source location had a significant effect on the plume dispersion due to the irregularity of the urban landscape. The location of the tallest obstacle in this domain with respect to the source position defined the size and shape of tracer plumes in this study. Model results based upon a Reynolds stress closure scheme were also compared to the vertical concentration profiles. For this location, the isothermal case underestimated concentrations; however, the case with thermal buoyancy resulted in concentrations within 25% of the observations.« less
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  • This paper describes new research being performed to improve understanding of seismic waves generated by underground nuclear explosions (UNE) by using full waveform simulation, high-performance computing and three-dimensional (3D) earth models. The goal of this effort is to develop an end-to-end modeling capability to cover the range of wave propagation required for nuclear explosion monitoring (NEM) from the buried nuclear device to the seismic sensor. The goal of this work is to improve understanding of the physical basis and prediction capabilities of seismic observables for NEM including source and path-propagation effects. We are pursuing research along three main thrusts. Firstly,more » we are modeling the non-linear hydrodynamic response of geologic materials to underground explosions in order to better understand how source emplacement conditions impact the seismic waves that emerge from the source region and are ultimately observed hundreds or thousands of kilometers away. Empirical evidence shows that the amplitudes and frequency content of seismic waves at all distances are strongly impacted by the physical properties of the source region (e.g. density, strength, porosity). To model the near-source shock-wave motions of an UNE, we use GEODYN, an Eulerian Godunov (finite volume) code incorporating thermodynamically consistent non-linear constitutive relations, including cavity formation, yielding, porous compaction, tensile failure, bulking and damage. In order to propagate motions to seismic distances we are developing a one-way coupling method to pass motions to WPP (a Cartesian anelastic finite difference code). Preliminary investigations of UNE's in canonical materials (granite, tuff and alluvium) confirm that emplacement conditions have a strong effect on seismic amplitudes and the generation of shear waves. Specifically, we find that motions from an explosion in high-strength, low-porosity granite have high compressional wave amplitudes and weak shear waves, while an explosion in low strength, high-porosity alluvium results in much weaker compressional waves and low-frequency compressional and shear waves of nearly equal amplitude. Further work will attempt to model available near-field seismic data from explosions conducted at NTS, where we have accurate characterization of the sub-surface from the wealth of geological and geophysical data from the former nuclear test program. Secondly, we are modeling seismic wave propagation with free-surface topography in WPP. We have model the October 9, 2006 and May 25, 2009 North Korean nuclear tests to investigate the impact of rugged topography on seismic waves. Preliminary results indicate that the topographic relief causes complexity in the direct P-waves that leads to azimuthally dependent behavior and the topographic gradient to the northeast, east and southeast of the presumed test locations generate stronger shear-waves, although each test gives a different pattern. Thirdly, we are modeling intermediate period motions (10-50 seconds) from earthquakes and explosions at regional distances. For these simulations we run SPECFEM3D{_}GLOBE (a spherical geometry spectral element code). We modeled broadband waveforms from well-characterized and well-observed events in the Middle East and central Asia, as well as the North Korean nuclear tests. For the recent North Korean test we found that the one-dimensional iasp91 model predicts the observed waveforms quite well in the band 20-50 seconds, while waveform fits for available 3D earth models are generally poor, with some exceptions. Interestingly 3D models can predict energy on the transverse component for an isotropic source presumably due to surface wave mode conversion and/or multipathing.« less
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