| Project/Area Number |
02452119
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| Research Category |
Grant-in-Aid for General Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Research Field |
Fluid engineering
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| Research Institution | KYUSHU UNIVERSITY |
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Principal Investigator |
MATSUO Kazuyasu Kyushu University, Graduate School of Engineering Sciences, Professor, 総合理工学研究科, 教授 (30037759)
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| Co-Investigator(Kenkyū-buntansha) |
AOKI Toshiyuki Kyushu University, Graduate School of Eng.Sciences, Associate Professor, 総合理工学研究科, 助教授 (20150922)
川越 茂敏 九州大学, 総合理工学研究科, 助手 (10044546)
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| Project Period (FY) |
1990 – 1992
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| Project Status |
Completed (Fiscal Year 1992)
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| Budget Amount *help |
¥6,500,000 (Direct Cost: ¥6,500,000)
Fiscal Year 1992: ¥1,200,000 (Direct Cost: ¥1,200,000)
Fiscal Year 1991: ¥1,900,000 (Direct Cost: ¥1,900,000)
Fiscal Year 1990: ¥3,400,000 (Direct Cost: ¥3,400,000)
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| Keywords | Supersonic flow / Shock wave / Interaction with boundary layer / Post-shock expansion / Internal flow |
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| Research Abstract |
1. The post-shock expansion phenomenon caused by the interaction of a normal shock wave with a turbulent boundary layer in supersonic internal flows is responsible for the curviness of interacting shock, the flow blockage, and the expansion waves behind the bifurcation shock system. The post-shock expansion appears as the shock-induced separation occurs.
2. The post-shock expansion becomes stronger as the flow Mach number as well as the divergence angles of the nozzle or diffuser increases. As the Mach number increases over a critical value, the post-shock expansion transforms into the pseudo-shock pattern.
3. The incipient post-shock expansion occurs at nearly constant wall Mach number even the divergence angle of diffuser is varied. It implies that the concept of free interaction observed in a variety of external flows should be also applied to internal supersonic flows.
4. The unsteadiness caused by the shock wave/turbulent boundary layer interaction was investigated experimentally. The frequencies of oscillating shock wave in internal flows are much lower than those in external flows. The maximum root-mean-square values of fluctuating pressures increase with an increase in flow Mach number and they are significantly affected by flow separation. A flow model of oscillating shock waves in internal supersonic flows is presented.
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