1989 Fiscal Year Final Research Report Summary
A study on the suppression of oscillation of pseudo-shock waves by means of passive boundary layer control
| Project/Area Number |
62460094
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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 Eng. Sciences, Professor, 総合理工学研究科, 教授 (30037759)
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| Co-Investigator(Kenkyū-buntansha) |
MOCHIZUKI Hiroaki Kyushu University, Graduate School of Eng. Sciences, Research Associate, 総合理工学研究科, 助手 (70038058)
AOKI Toshiyuki Kyushu University, Graduate School of Eng. Sciences, Associate Professor, 総合理工学研究科, 助教授 (20150922)
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| Project Period (FY) |
1987 – 1989
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| Keywords | Pseudo-shock wave / Boundary layer / Passive control / Compressible flow |
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| Research Abstract |
1. In order to suppress the oscillation of pseudo-shock waves in ducts, the technique of passive boundary layer control has been applied to the pseudo-shock waves in a rectangular duct. The passive control of shock-boundary layer interactions consists of a porous surface and a cavity or plenum underneath located in the region of shock boundary layer interaction. In this study, the Mach number upstream of the pseudo-shock was kept constant, and the porosity of the porous surface and the cavity volume were varied. The effects of these parameters on the static and dynamic characteristics of pseudo-shocks were made clear.
2. The pseudo-shock is affected substantially by the passive boundary layer control and a flow pattern like, so called, a shockless state, which is suggested as a limiting state of the dissipative phenomenon in the pseudo-shock region by L. Crocco, has been observed by a schlieren optical method and by pressure measurements. However, the length of the pseudo- shock and the pressure ratio across the pseudo-shock are not affected by the passive control of the boundary layer.
3. When the technique of passive boundary layer control is applied to the pseudo-shock so that the foot the bifurcated head shock is located at the upstream edge of the porous surface, the oscillation of the pseudo-shock is substantially suppressed. In particular, the components of high frequencies of the oscillation almost vanish by the passive control. This may be due to the fact that the boundary layer which is separated from the wall by the interaction with the shock would reattach and become stable. From this point, it may be concluded that this method is effective to suppress the oscillation of pseudo-shock waves.
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Research Products
(4 results)
