Development of a perturbative approach for a slow flow past a small spherical particle and clarification of the inverse Magnus effect

2015 Fiscal Year Final Research Report

• Project/Area Number: 25820041
• Research Category: Grant-in-Aid for Young Scientists (B)
• Allocation Type: Multi-year Fund
• Research Field: Fluid engineering
• Research Institution: The University of Electro-Communications
• Principal Investigator: Taguchi Satoshi 電気通信大学, 情報理工学(系)研究科, 准教授 (90448168)
• Project Period (FY): 2013-04-01 – 2016-03-31
• Keywords: 逆マグナス効果 / ボルツマン方程式 / 球 / 抵抗 / 揚力 / 希薄気体力学 / 漸近接続展開

Outline of Final Research Achievements

The lift and drag acting on a spinning sphere placed in a slow uniform flow were investigated on the basis of molecular gas dynamics. It was shown that there is a threshold of the sphere size, below which the direction of the lift is inverted (the inverse Magnus effect). To analyze the flow, a perturbation method of the Boltzmann equation for a flow around a sphere was newly developed. A formula that dramatically simplifies the computation of the lift was found and used. A higher-order correction to the existing drag formula was also obtained.

Free Research Field

流体力学，希薄気体力学，非平衡気体力学