论文标题
不连续的壁温度引起的略有稀疏气流的通用滑动理论
A generalized slip-flow theory for a slightly rarefied gas flow induced by discontinuous wall temperature
论文作者
论文摘要
当我们关注稍微稀疏的气体运动时，在动力学系统中得出的流体动力型方程及其边界条件在动力学理论中非常重要。它提供了直接求解Boltzmann方程的有效替代方案，更重要的是，它清楚地描绘了近乎智能方案中的流程结构。但是，现有滑动理论的适用性仅限于边界形状和动力学边界条件都是边界坐标的平滑函数的情况，例如，动力学边界条件具有跳跃不连续性的情况。在本文中，我们讨论了由不连续的墙温度在简单的两面问题中引起的略有稀有气体的运动，并说明了如何扩展现有理论。讨论基于我们最近的论文[Taguchi和Tsuji，J。Fluid Mech。 897，A16（2020）]得到了新引入的动力学边界层（Knudsen区）的一些初步数值结果的支持，从中得出了流速的源源条件。
A system of fluid-dynamic-type equations and their boundary conditions derived from a system of the Boltzmann equation is of great importance in kinetic theory when we are concerned with the motion of a slightly rarefied gas. It offers an efficient alternative to solving the Boltzmann equation directly and, more importantly, provides a clear picture of the flow structure in the near-continuum regime. However, the applicability of the existing slip-flow theory is limited to the case where both the boundary shape and the kinetic boundary condition are smooth functions of the boundary coordinates, which precludes, for example, the case where the kinetic boundary condition has a jump discontinuity. In this paper, we discuss the motion of a slightly rarefied gas caused by a discontinuous wall temperature in a simple two-surface problem and illustrate how the existing theory can be extended. The discussion is based on our recent paper [Taguchi and Tsuji, J. Fluid Mech. 897, A16 (2020)] supported by some preliminary numerical results for the newly introduced kinetic boundary layer (the Knudsen zone), from which a source-sink condition for the flow velocity is derived.
