论文标题
稀疏气体中的马格努斯效应
Inverse Magnus effect in a rarefied gas
论文作者
论文摘要
根据玻尔兹曼方程的Bhatnagar-gross-krook（BGK）模型，研究了在稀有气体中浸入稀有气体的旋转球上施加的横向力，假设球体上的麦克斯韦边界条件。在几项现有研究中，已经表明，作用在球体上的横向力，也称为马格努斯力，在自由分子和连续性流中具有相反的迹象。本研究旨在阐明力在knudsen数字（即球形半径与分子平均自由路径的相互比率）方面澄清，对球体表面容纳的影响特别感兴趣。发现横向力改变符号的knudsen数字的阈值仅取决于适应系数，这表明阈值中某些鲁棒性。本研究是先前工作的扩展[S. Taguchi和T. Tsuji，J。Fluid。机械。 933，A37（2022）]，其中完全考虑了完整的住宿情况（弥漫反射）。
The transverse force exerted on a rotating sphere immersed in an otherwise uniform flow of a rarefied gas is investigated based on the Bhatnagar-Gross-Krook (BGK) model of the Boltzmann equation assuming the Maxwell boundary condition on the sphere. In several existing studies, it has been shown that the transverse force acting on the sphere, also known as the Magnus force, has opposite signs in the free molecular and continuum flows. The present study intends to clarify the force's transition in terms of the Knudsen number (i.e., the reciprocal ratio of the sphere radius to the molecular mean free path) with a particular interest in the impact of the sphere's surface accommodation. It is found that the threshold of the Knudsen number, at which the transverse force changes the sign, depends only weakly on the accommodation coefficient, suggesting certain robustness in the threshold. The present study is an extension of the previous work [S. Taguchi and T. Tsuji, J. Fluid. Mech. 933, A37 (2022)], in which the case of complete accommodation (diffuse reflection) is exclusively considered.
