Uncertainty quantification in rarefied dynamics of molecular gas: Rate effect of thermal relaxation

Li，Qi1; Zeng，Jianan1; Su，Wei2; Wu，Lei1,3

2021

10.1017/jfm.2021.338

JOURNAL OF FLUID MECHANICS   影响因子和分区

0022-1120

1469-7645

The thermal conductivity of a molecular gas consists of the translational and internal parts. Although in continuum flows the total thermal conductivity itself is adequate to describe the heat transfer, in rarefied gas flows they need to be modelled separately, according to the relaxation rates of translational and internal heat fluxes in an homogeneous system. This paper is dedicated to quantifying how these relaxation rates affect rarefied gas dynamics. The kinetic model of Wu et al. (J. Fluid Mech., vol. 763, 2015, pp. 24-50) is adapted to recover the relaxation of heat fluxes, which is validated by the direct simulation Monte Carlo method. Then the model of Wu et al., which has the freedom to adjust the relaxation rates, is used to investigate the rate effects of thermal relaxation in problems such as the normal shock wave, creep flow driven by Maxwell's demon and thermal transpiration. It is found that the relaxation rates of heat flux affect rarefied gas flows significantly, even when the total thermal conductivity is fixed.

rarefied gas flow

SCI ; EI

英语

第一 ; 通讯

WOS:000646616300001

20212010347525

Flow of gases ; Gas dynamics ; Gases ; Heat flux ; Heat transfer ; Molecules ; Monte Carlo methods ; Shock waves

Gas Dynamics:631.1.2 ; Thermodynamics:641.1 ; Heat Transfer:641.2 ; Mathematical Statistics:922.2 ; Classical Physics; Quantum Theory; Relativity:931 ; Atomic and Molecular Physics:931.3

ENGINEERING

2-s2.0-85105553111

Scopus

1.Department of Mechanics and Aerospace Engineering,Southern University of Science and Technology,Shenzhen,518055,China
2.School of Engineering,University of Edinburgh,Edinburgh,EH9 3FB,United Kingdom
3.Guangdong-Hong Kong-Macao Joint Laboratory for Data-Driven Fluid Mechanics and Engineering Applications,Southern University of Science and Technology,Shenzhen,518055,China

Li，Qi,Zeng，Jianan,Su，Wei,et al. Uncertainty quantification in rarefied dynamics of molecular gas: Rate effect of thermal relaxation[J]. JOURNAL OF FLUID MECHANICS,2021,917.

Li，Qi,Zeng，Jianan,Su，Wei,&Wu，Lei.(2021).Uncertainty quantification in rarefied dynamics of molecular gas: Rate effect of thermal relaxation.JOURNAL OF FLUID MECHANICS,917.

Li，Qi,et al."Uncertainty quantification in rarefied dynamics of molecular gas: Rate effect of thermal relaxation".JOURNAL OF FLUID MECHANICS 917(2021).