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Title: Discrete velocity computations with stochastic variance reduction of the Boltzmann equation for gas mixtures

We extend a variance reduced discrete velocity method developed at UT Austin [1, 2] to gas mixtures with large mass ratios and flows with trace species. The mixture is stored as a collection of independent velocity distribution functions, each with a unique grid in velocity space. Different collision types (A-A, A-B, B-B, etc.) are treated independently, and the variance reduction scheme is formulated with different equilibrium functions for each separate collision type. The individual treatment of species enables increased focus on species important to the physics of the flow, even if the important species are present in trace amounts. The method is verified through comparisons to Direct Simulation Monte Carlo computations and the computational workload per time step is investigated for the variance reduced method.
Authors:
; ;  [1]
  1. ASE-EM Department, UT Austin, 210 East 24th St, C0600, Austin, TX 78712 (United States)
Publication Date:
OSTI Identifier:
22390541
Resource Type:
Journal Article
Resource Relation:
Journal Name: AIP Conference Proceedings; Journal Volume: 1628; Journal Issue: 1; Conference: 29. International Symposium on Rarefied Gas Dynamics, Xi'an (China), 13-18 Jul 2014; Other Information: (c) 2014 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; BOLTZMANN EQUATION; COLLISIONS; COMPARATIVE EVALUATIONS; COMPUTERIZED SIMULATION; DISTRIBUTION FUNCTIONS; EQUILIBRIUM; MASS; MIXTURES; MONTE CARLO METHOD; SPACE; STOCHASTIC PROCESSES; VELOCITY