Project/Area Number  03452098 
Research Category 
GrantinAid for Scientific Research (B).

Research Field 
Aerospace engineering

Research Institution  KYOTO UNIVERSITY 
Principal Investigator 
SONE Yoshio Kyoto University, Faculty of Engineering, Professor, 工学部, 教授 (80025923)

CoInvestigator(Kenkyūbuntansha) 
田中 貞映 神戸商船大学, 商船学部, 教授 (00031469)
OHWADA Taku Kyoto University, Faculty of Engineering, Associate Professor, 工学部, 助教授 (40223987)
AOKI Kazuo Kyoto University, Faculty of Engineering, Professor, 工学部, 教授 (10115777)
SUGIMOTO Hiroshi Kyoto University, Faculty of Engineering, Instructor, 工学部, 助手 (50222055)

Project Fiscal Year 
1991 – 1993

Project Status 
Completed(Fiscal Year 1993)

Budget Amount *help 
¥7,000,000 (Direct Cost : ¥7,000,000)
Fiscal Year 1993 : ¥900,000 (Direct Cost : ¥900,000)
Fiscal Year 1992 : ¥1,200,000 (Direct Cost : ¥1,200,000)
Fiscal Year 1991 : ¥4,900,000 (Direct Cost : ¥4,900,000)

Keywords  Rarefied Gas Dynamics / Boltzmann equation / Evaporation and condensation / Shock waves / Kinetic theory of gases / Thermophoresis / Numerical analysis / Low density flows / 希薄気体力学 / ボルツマン方程式 / 蒸発・凝縮 / 熱泳動 / 低圧気流 / 気体論 / 膨張流 / 数値解析 / 気体分子運動論 / 低密度(希薄)気体 / 蒸発 / 自由膨張流 / 抗力 / クヌーセン層 / 衝撃波 / 凝縮 / クヌセン層 
Research Abstract 
The result of this project is summarized as follows. A.Flows accompanying evaporation and condesation Longstanding problems, evaporating flows from a cylindrical or spherical condensed phase into a vacuum or into a space occupied with its vapor, are analyzed on the basis of the kinetic theory, and the comprehensive feature of the flows, especially the decisive difference between the flow from a cylinder and that from the sphere, are clarified. The drag problem of a volatile particle is also studied. B.Flows around a body Various difficulties in carrying out numerical analysis of flows around a body, i.e., discontinuity of the velocity distribution function in a gas, the complicated collision integral, and infinite domain problems, are resolved. With aid of the result, various important flows around bodies are analyzed accurately for the whole range of the Knudsen number. C.Flows induced by temperature fields The thermophoresis problem for a spherical particle is analyzed accurately on the basis of the standard Boltzmann equation for the whole range of the Knudsen number, and its comprehensive feature are clarified. The thermal creep flow, which plays an important role in the thermophoresis, is examined experimentally, and fundamental theoretical results are confirmed. D.Shock waves The structure of plane shock waves is analyzed accurately on the basis of the standard Boltzmann equation for hardsphere molecules. Shock waves that appears in expanding flows are also analyzed. E.Fundamental properties of solutions of Boltzmann equation Various important properties in analyzing and understanding rarefied gas flows, i.e., existence of discontinuity of the velocity distribution function in a gas around a convex body and its relation with the S layr at the bottom of Knudsen layr, mathematical properties of steady solutions of a highly rarefied gas, nonlinear effects in a nearly uniform equilibrium flow and thier examples, are clarified.
