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From: Jacob S. <jsc...@pp...> - 2019-02-28 21:10:19
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Dear SPARTA users, I'm trying to understand better the relationships between the various discretizations (N_c, delta-x, delta-x) and their effects on properties such as viscosity and thermal conductivity. I have a few questions about the applicability of the result by Rader et al [1] in their Equation (23). I hope these questions are not inappropriate for this mailing list. 1) Just making sure: is sampling in SPARTA equivalent to 'standard' DSMC, MCS, as explained in [1] ? 2) Just making sure: is SPARTA's algorithm DSMC94 as in [2]? 3) If I understand correctly, Rader et al's Equation (23) expresses discretization errors for thermal conductivity when sampled using the MSCS scheme, using a hard-sphere gas. Though Figure 6 in the paper seems to imply it could be extended to use with MCS schemes as well? 4) Has anyone undertaken a study similar to [1] for viscosity coefficients, such as with Couette flow? 5) ... for a VHS or VSS gas, rather than a hard sphere gas? I admit my ignorance of the methods of the Chapman-Enskog procedure; would it be reasonable to expect similar discretization errors? I understand of course the exact coefficients of the terms in Equation (23) only strictly apply to the specific scenario of Fourier heat flow with certain temperature differences, wall separations, etc. Also, as a PhD student especially, the answer to most of these might be 'go do some convergence studies yourself'. I would appreciate any insight to make sure I'm not spending *too* much time reproducing existing literature. Best, Jacob Schwartz [1] Rader, D. J., M. A. Gallis, J. R. Torczynski, and W. Wagner. “Direct Simulation Monte Carlo Convergence Behavior of the Hard-Sphere-Gas Thermal Conductivity for Fourier Heat Flow.” *Physics of Fluids* 18, no. 7 (July 2006): 077102. https://doi.org/10.1063/1.2213640. [2] Direct Simulation Monte Carlo: The Quest for Speed, M. A. Gallis, J. R. Torczynski, S. J. Plimpton, D. J. Rader, T. Koehler, 29th Intl Symposium on Rarefied Gas Dynamics in Xi'an, China, AIP Conf Proc, 1628, 27 (2014) -- Jacob Schwartz PhD Candidate, Princeton Program in Plasma Physics S206, Princeton Plasma Physics Laboratory 609-243-2659 <%28609%29%20243-2659> |