Multiple-temperature kinetic model for continuum and near continuum flows

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	Multiple-temperature kinetic model for continuum and near continuum flows
	Xu K; Liu HW; Jiang JZ(蒋建政)
刊名	Physics of Fluids
	2007
卷号	19 期号:1 页码:16101-1-16101-12
ISSN号	1070-6631
中文摘要	A gas-kinetic model with multiple translational temperature for the continuum and near continuum flow simulations is proposed. The main purpose for this work is to derive the generalized Navier-Stokes equations with multiple temperature. It is well recognized that for increasingly rarefied flowfields, the predictions from continuum formulation, such as the Navier-Stokes equations lose accuracy. These inaccuracies may be partially due to the single temperature assumption in the standard Navier-Stokes equations. Here, based on an extended Bhatnagar-Gross-Krook (BGK) model with multiple translational temperature, the numerical scheme for its corresponding Navier-Stokes equations is also constructed. In the current approach, the energy exchange between x, y, and z directions is modeled through the particle collision, and individual energy equation in different direction is obtained. The kinetic model, newly constructed is an enlarged system in comparison with Holway's ellipsoid statistical BGK model (ES-BGK). The detailed difference is presented in this paper. In the newly derived "Navier-Stokes" equations from the current model, all viscous terms are replaced by the temperature relaxation terms. The relation between the stress and strain in the standard Navier-Stokes equations is recovered only in the limiting case when the flow is close to the equilibrium, such as small temperature differences in different directions. In order to validate the generalized Navier-Stokes equations, we apply them to the study of Couette and Poiseuille flows with a wide range of Knudsen numbers. In the continuum flow regime, the standard Navier-Stokes solutions are precisely recovered. In the near continuum flow regime, the simulation results are compared with the direct simulation Monte Carlo solutions. The anomalous phenomena in the pressure and temperature distributions from the standard Navier-Stokes equations in the Poiseuille flow case at Kn=0.1 are well resolved by the generalized Navier-Stokes equations. This paper clearly shows that many thermal nonequilibrium phenomena in the near continuum flow regime can be well captured by modifying some assumptions in the standard Navier-Stokes equations.
学科主题	力学
类目[WOS]	Mechanics ; Physics, Fluids & Plasmas
研究领域[WOS]	Mechanics ; Physics
收录类别	SCI ; EI
语种	英语
WOS记录号	WOS:000243927500026
公开日期	2007-06-15
内容类型	期刊论文
源URL	[http://dspace.imech.ac.cn/handle/311007/15485]
专题	力学研究所_力学所知识产出(1956-2008)
推荐引用方式 GB/T 7714	Xu K,Liu HW,Jiang JZ. Multiple-temperature kinetic model for continuum and near continuum flows[J]. Physics of Fluids,2007,19(1):16101-1-16101-12.
APA	Xu K,Liu HW,&蒋建政.(2007).Multiple-temperature kinetic model for continuum and near continuum flows.Physics of Fluids,19(1),16101-1-16101-12.
MLA	Xu K,et al."Multiple-temperature kinetic model for continuum and near continuum flows".Physics of Fluids 19.1(2007):16101-1-16101-12.