Project/Area Number  10044151 
Research Category 
GrantinAid for Scientific Research (B).

Section  Joint Research . 
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) 
VINICIO Boff ローマ大学, 工学部, 教授
CALRO Cercig ミラノ工科大学, 工学部, 教授
杉元 宏 京都大学, 工学研究科, 講師 (50222055)
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, Professor, 工学研究科, 教授 (10115777)
TAKATA Shigeru Kyoto University, Graduate School of Engineering, Associate Professor, 工学研究科, 助教授 (60271011)

Project Fiscal Year 
1998 – 1999

Project Status 
Completed(Fiscal Year 1999)

Budget Amount *help 
¥3,400,000 (Direct Cost : ¥3,400,000)
Fiscal Year 1999 : ¥1,600,000 (Direct Cost : ¥1,600,000)
Fiscal Year 1998 : ¥1,800,000 (Direct Cost : ¥1,800,000)

Keywords  Benard problem / bifurcation / stability / evaporation and condensation / shock wave / vacuum pump / thermal creep flow / cylindrical Couette flow / ベナール問題 / 分岐 / 安定性 / 蒸発・凝縮 / 衝撃波 / 真空ポンプ / 熱ほふく流 / 円管クエット流 / 蒸気・凝縮 / 熱遷移流 / ボルツマン方程式 / テイラー・クエット流 / 希薄気体 
Research Abstract 
1. The twodimensional Benard problem for a rarefied gas was studied by both Japanese group (JG) and Italian group (IG). JG found a new bound of the parameter region for a stable solution without a flow, which has not been known in classical fluid dynamics. JG also investigated the stability of multiroll solutions and clarified the process of transition from unstable multiroll solutions to stable ones. IG showed an example of the flow with chaotic behavior using the direct simulation Monte Carlo (DSMC) method. 2. JG studied bifurcation of the Couette flow between two coaxial circular cylinders made of the condensed phase of a gas. First, in the case where only the inner cylinder is rotating, the structure of the bifurcation was investigated by analyzing the initialvalue problems by the DSMC method, and the relation between the initial conditions and the stable steady solutions was clarified. Next, in the general case, where the outer cylinder is also rotating, a systematic asymptotic
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analysis was carried out under the condition that the rotation of the cylinders is slow and the gas is slightly rarefied. As a result, the structure of the bifurcation was clarified comprehensively, and various new types of bifurcated solution were discovered. 3. JG performed an experimental study of the possibility of a vacuum pump using a rarefied gas flow induced by temperature fields. As a result, a flow consistent with the flow predicted numerically was observed, and the practicality of the pump was demonstrated. JG also summarized the previous results for the rarefied gas flows induced by temperature fields, including this experiment. 4. JG provided a comprehensive and systematic summary of the existing results for flows of a gas condensing onto its condensed phase and gave the information to IG. 5. JG and IG cooperated to study the structure of an infinitely strong shock wave and clarified the singularity in the velocity distribution function by means of a finitedifference method developed by JG. JG also developed a numerical scheme of higher accuracy for timedependent problems of the Boltzmann equation. Less
