A GENERALIZED NAVIER-STOKES CONSTITUTION RELATION FOR MULTISCALE GAS FLOWS
As a gas flowing over a solid surface, there exists a kinetic boundary layer, also known as Knudsen layer (KL) near the surface in which the velocity changes rapidly. The KL is different from the viscous boundary layer usually encountered in hydrodynamic problems. The thickness of the KL is usually in the order of the mean-free path (MFP) of the gas system. Within the KL, the inter-molecular collisions in the KL are much inefficient than that far from the wall so that the quasi-thermodynamic-equilibrium assumption, upon which the Navier-Stokes constitution depends, does not hold any more. Therefore, it is generally thought that this linear Navier-Stokes constitutive relation is invalid. For many engineering problems, the KL is negligible and the flow within the KL can be well described by the Navier-Stokes equation. However, for non-continuum flows where the KL takes a large portion, it becomes critical to capture the gas motion in the KL. This work aims to develop an extended Navier-Stokes constitution with an effective viscosity which considers the KL effect.
Zhaoli Guo Chuguang Zheng
National Laboratory of Coal Combustion,Huazhong University of Science and Technology,Wuhan,430074, C National Laboratory of Coal Combustion, Huazhong University of Science and Technology,Wuhan,430074,
国际会议
2nd International Conference on Computational Methods for Thermal Problems(第二届热问题计算方法国际会议)
大连
英文
232-235
2011-09-05（万方平台首次上网日期，不代表论文的发表时间）