| Project/Area Number |
17560694
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Aerospace engineering
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| Research Institution | Osaka Prefecture University |
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Principal Investigator |
ARAI Takakage Osaka Prefecture University, Graduate School of Engineering, Professor, 工学研究科, 教授 (10175945)
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| Co-Investigator(Kenkyū-buntansha) |
SAKAUE Shoji Osaka Prefecture University Grnluate School of Engineeing, Graduate School of Engineering, Instructor, 工学研究科, 助手 (70244655)
TANATSUGU Nobuhiro Muroran Institute of Technology, School of Engineering, Professor, 工学部, 教授 (70013737)
MIZOBATA Kazuhide Muroran Institute of Technology, School of Engineering, Associate Professor, 工学部, 助教授 (00271875)
MINATO Ryojiro Muroran Institute of Technology, School of Engineering, Instructor, 工学部, 助手 (20360969)
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| Project Period (FY) |
2005 – 2006
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| Project Status |
Completed (Fiscal Year 2006)
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| Budget Amount *help |
¥3,500,000 (Direct Cost: ¥3,500,000)
Fiscal Year 2006: ¥1,700,000 (Direct Cost: ¥1,700,000)
Fiscal Year 2005: ¥1,800,000 (Direct Cost: ¥1,800,000)
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| Keywords | Supersonic Mixing / Boundary Layer Transition / Scramjet / Streamwise Vortices / Catalytic Reaction / PIV / Vortex Breakdown / シュリーレン法 |
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| Research Abstract |
This research has two parts of the mixing evaluation and mixing enhancement.
First, an experimental study was carried out to confirm the validity of time series evaluation of supersonic mixing condition by using catalytic reaction on a platinum wire. Gaseous hydrogen was injected into supersonic free-stream (Mach 1.81) from injector. Time series condition of supersonic mixing was evaluated by using W-type probe which has a platinum wire and reference wire (nickel wire). The evaluation was done by simultaneously measuring each electric power supplied by each electric circuit which kept the temperature of wire constant. Specifically supplied electric power to Pt wire depended on catalytic heat release rate (giving hydrogen concentration) and flow convection. Meanwhile that to Ni wire depended on flow convection. The result showed that correlation coefficient between these electric powers increased when mixing developed. Investigations were also conducted for helium, air and no secondary i
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njectant cases to compare with the hydrogen injectant case. The results indicated that it was possible to measure the time-series behavior of air-hydrogen supersonic mixing layer or coherent motion of turbulence by using this evaluation.
Second, for supersonic mixing enhancement, experiments suggested that large scale streamwise vortices seemed to be the most advantageous, for example, FFT spectrum analysis of mass flux fluctuations showed that the power spectrum partly follows Kolmogorov's -5/3 power law, indicating that the breakdown of streamwise vortices occurred to generate small scale turbulent eddies of high mixing power. The present study examined the breakdown process of streamwise vortices by using PIV, schlieren visualization, hot-wire anemometer and CFD. The experimental results showed that the breakdown of streamwise vortices into small scale turbulence occured at the vortex Reynolds number ReΓ=Γ/v=1.3×10^4 or more, and that the lateral structure on streamewise vortices took a part in its breakdown process. From the computational analysis, the oscillation of shear layer from ramp could make the streamwise vortices unstable and cause its breakdown. Less
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