Dynamics of Gas Molecule near the Surface in Rarefied Flow

稀薄流中近表面气体分子动力学

• 批准号: 09450074
• 负责人: MATSUI Jun
• 金额: $ 5.25万
• 依托单位: Yokohama National University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (B)
• 财政年份: 1997
• 资助国家: 日本
• 起止时间: 1997 至 1998
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-09450074/
• 关键词: rarefied flow; gas surface interaction; diffuse scattering; boundary condition; molecular dynamics; 表面散乱; 付着分子; DSMC法; Maxwellモデル

1) Using the molecular-dynamics simulation method, the scattering process of gas molecule on the surface with adsorbale gas molecules. There are 4 patterns of scattering process, that associated with the distribution of energy-transfer from gas molecule to other molecules. The parameters such as mass ratio of gas molecule, potential coefficients, number of adsorbate on surface are changed in the simulation, and their dependency on the scattering process is studied.2) To study the sticking and escaping dynamics of gas molecule in thermal equilibrium stale, the behavior of Xenon molecules between two plate of Platinum are simulated for a long period. The escaping process has three types. Two of them are caused by interaction from adsorbated gas molecule. Also the dependency of escaping molecules on the coverage coefficients are studied.3) The effrect of roughness of the surface to rarefied gas flow is estimated by "Direct Simulation Monte Carlo" method. The test case is Couette flow between two plates. One plate has some roughness that simulate the shape made by cutting bite of the lathe. With high Knudsen number, the effect of roughness reaches to all the flow field by some vortex structure at the sharp edge of roughness. The parameter study is done on the height of roughness, angle of bite, and Knudsen number.

1）采用分子动力学模拟方法，研究气体分子在可吸附气体分子表面的散射过程。散射过程有 4 种模式，与从气体分子到其他分子的能量转移分布相关。模拟中改变了气体分子的质量比、势能系数、表面吸附质数量等参数，并研究了它们对散射过程的依赖性。2)为了研究热平衡状态下气体分子的粘附和逃逸动力学，对两块铂板之间的氙分子行为进行了长时间的模拟。转义过程分为三种类型。其中两种是由吸附气体分子相互作用引起的。并研究了逃逸分子对覆盖系数的依赖性。3)采用“直接模拟蒙特卡罗”方法估计了表面粗糙度对稀薄气流的影响。测试案例是两个板之间的库埃特流。一块板具有一定的粗糙度，模拟车床切削咬合形成的形状。在努森数较高的情况下，粗糙度的影响通过粗糙度尖锐边缘处的某种涡结构到达整个流场。参数研究是针对粗糙度高度、咬合角和努森数进行的。

项目成果

J.MATSUI,M.NAKAKITA,and Y.MATSUMOTO: "Numerical Study of Molecular Scattering on the Surface with Adsorbate Molecules" Proc.of 21th International Symposium on Rarefied Gas Dynamics. (in printing).

J.MATSUI、M.NAKAKITA 和 Y.MATSUMOTO：“吸附分子表面分子散射的数值研究”第 21 届稀薄气体动力学国际研讨会论文集。

J.MATSUI, 他: "Numerical Study of Molecular Scattering on the Surface with Adsorbate Molecules" Proc.of 21th International Symposium on Rarefied Gas Dynamics. (in printing).

J.MATSUI 等人：“吸附分子表面分子散射的数值研究”，第 21 届国际稀薄气体动力学研讨会论文集（印刷中）。