Project/Area Number  08455463 
Research Category 
GrantinAid for Scientific Research (B)

Section  一般 
Research Field 
Aerospace engineering

Research Institution  KYOTO UNIVERSITY 
Principal Investigator 
SONE Yoshio Kyoto University, Graduate School of Engineering, Professor, 工学研究科, 教授 (80025923)

CoInvestigator(Kenkyūbuntansha) 
SUGIMOTO Hiroshi Kyoto University, Graduate School of Engineering, Lecturer, 工学研究科, 講師 (50222055)
TAKATA Sigeru Kyoto University, Graduate School of Engineering, Associate Professor, 工学研究科, 助教授 (60271011)
OHWADA Taku Kyoto University, Graduate School of Engineering, Associate Professor, 工学研究科, 助教授 (40223987)
AOKI Kazuo Kyoto University, Graduate School of Engineering, Proefssor, 工学研究科, 教授 (10115777)

Project Fiscal Year 
1996 – 1997

Project Status 
Completed(Fiscal Year 1997)

Budget Amount *help 
¥7,800,000 (Direct Cost : ¥7,800,000)
Fiscal Year 1997 : ¥1,200,000 (Direct Cost : ¥1,200,000)
Fiscal Year 1996 : ¥6,600,000 (Direct Cost : ¥6,600,000)

Keywords  rarefied gas / stability / bifurcation / TaylorCouette flow / Boltzmean equation / Benard problem / evaporation and condensation / thermal creep flow / 希薄気体 / 安定性 / 分岐 / ボルツマン方程式 / テーラー・クェット流 / ベナル問題 / 蒸発・凝縮 / 熱ほふく流 / テーラー・クェット問題 
Research Abstract 
1.the Benard problem for a rarefied gas is studied numerically on the basis of kinetic theory. The main results are as follows : (1)The range of the parameters for which a steady convection flow exists and steady flow patterns ; 2)transition processes to various steady patterns from various initial conditions ; and 3)stability of multiroll solutions, which are arrays of several stable singleroll solutions. In (1) there exists a different branch of the stability boundary, not found in the classical gas dynamies. 2)The stability of the cylindrical Couette flow for a rarefied flow is studied by the direct simulation Monte Carlo method, and the parameter range where the steady Taylor vortex flow exists and the structure of the flow are clarified. The analysis is extended to the case where there is a temperature difference between the two cylinders. It is found that the temperature difference acts so as to stabikize flow, against the result inferred from the Benard problem. 3.The study of the subject 2 is extended to the case where the cylinders are made of the condensed phase of the gas, and a new type of bifurcation of flow is found in a circumferentially and axially uniform flow. 4.Asymptotic analysis in the continuum limit of the problem 3 shows that the rerefaction effect which is supposed to vanish in the continuum limit remains in this limit (a ghost effect). This is a striking result showing the incompleteness of the classical (conventional) gas dynamics and necessity of kinetic theory even in the analysis of the continuum limit (a new role of kinetic theory). 5.Flows induced around a heated plate in a rarefied gas in a gravitational field is stucied. 6.High speed flows of a rarefied gas past a flat plate are studied.
