Multiscale simulation of coexisting turbulent and rarefied gas flows

Fuente: arXiv
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Main Authors: Tian, Songyan, Wu, Lei
Format: Preprint
Published: 2024
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author Tian, Songyan
Wu, Lei
author_facet Tian, Songyan
Wu, Lei
contents Simulating complex gas flows from turbulent to rarefied regimes is a long-standing challenge, since turbulence and rarefied flow represent contrasting extremes of computational aerodynamics. We propose a multiscale method to bridge this gap. Our method builds upon the general synthetic iterative scheme for the mesoscopic Boltzmann equation, and integrates the $k$-$ω$ model in the macroscopic synthetic equation to address turbulent effects. We have not only validated this approach using the experimental data of turbulent flows, but also confirmed that the turbulence model exerts no undue influence on highly rarefied flows. Our method is then applied to opposing jet problems in hypersonic flight surrounding by rarefied gas flows, showing that the turbulence could cause significant impacts on the surface heat flux, which cannot be captured by the turbulent model nor the laminar Boltzmann solution alone. This study provides a viable framework for advancing our understanding of the interaction between turbulent and rarefied gas flows.
format Preprint
id arxiv_https___arxiv_org_abs_2408_08219
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle Multiscale simulation of coexisting turbulent and rarefied gas flows
Tian, Songyan
Wu, Lei
Fluid Dynamics
Simulating complex gas flows from turbulent to rarefied regimes is a long-standing challenge, since turbulence and rarefied flow represent contrasting extremes of computational aerodynamics. We propose a multiscale method to bridge this gap. Our method builds upon the general synthetic iterative scheme for the mesoscopic Boltzmann equation, and integrates the $k$-$ω$ model in the macroscopic synthetic equation to address turbulent effects. We have not only validated this approach using the experimental data of turbulent flows, but also confirmed that the turbulence model exerts no undue influence on highly rarefied flows. Our method is then applied to opposing jet problems in hypersonic flight surrounding by rarefied gas flows, showing that the turbulence could cause significant impacts on the surface heat flux, which cannot be captured by the turbulent model nor the laminar Boltzmann solution alone. This study provides a viable framework for advancing our understanding of the interaction between turbulent and rarefied gas flows.
title Multiscale simulation of coexisting turbulent and rarefied gas flows
topic Fluid Dynamics
url https://arxiv.org/abs/2408.08219