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Nakayama, Hiromasa; Leitl, B.*; Harms, F.*; Nagai, Haruyasu
Journal of Nuclear Science and Technology, 51(5), p.626 - 638, 2014/02
Times Cited Count：19 Percentile：81.41(Nuclear Science & Technology)We apply the LES model to turbulent flows and plume dispersion in an actual urban area. Although some of the turbulence and dispersion characteristics are quantitatively different from the wind tunnel experimental data, the distribution patterns are generally similar to those of the experiments. It is concluded that our LES model simulates reasonably the unsteady behavior of turbulent flows and plume dispersion even for complex heterogeneous urban areas.
Nakayama, Hiromasa; Leitl, B.*; Nagai, Haruyasu; Harms, F.*
Proceedings of International Workshop on Physical Modelling of Flow and Dispersion Phenomena (PHYSMOD 2011) (CD-ROM), 8 Pages, 2011/08
An accurate analysis of atmospheric dispersion is important for emergency responses against accidental and intentional releases of hazardous and radioactive materials within populated urban areas. In this study, we evaluate the Large-Eddy Simulation (LES) model performance in comparison with the experimental datasets from the wind tunnel simulations of turbulent flow and plume dispersion in Oklahoma City. First, comparing with the experiments of approach flow, the turbulence characteristics of LES approach flow are found to be good agreement with those of the experiment. From this result, LES approach flow corresponding to a neutral atmospheric boundary layer is considered to be obtained. Next, comparing with the experimental results of wind velocity and dispersion fields in the study site of Oklahoma City, it is found that the LES data are in good agreement with the experimental data.
Nakayama, Hiromasa; Leitl, B.*; Harms, F.*; Nagai, Haruyasu
no journal, ,
We have developed a LOcal-scale High-resolution atmospheric DIspersion Model using Large-Eddy Simulation (LOHDIM-LES) to respond to emergency situations resulting from accidental or deliberate releases of radioactive materials (e.g., a terrorist attack in an urban area). In this study, our objective is to examine the basic performance in comparison to wind tunnel experiments, and detect strength and weaknesses of the local scale emergency response tool LOHDIM-LES developed at Japan Atomic Energy Agency.
