| Project/Area Number |
02650124
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| Research Category |
Grant-in-Aid for General Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Research Field |
Fluid engineering
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| Research Institution | Hachinohe Institute of Technology (1991-1992)
Tohoku University (1990) |
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Principal Investigator |
ITO Yukio Hachinohe Institute of Technology, Faculty of Engineering, Associate Professor, 工学部, 助教授 (70006196)
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| Co-Investigator(Kenkyū-buntansha) |
NARASAKA Tsutomu Tohoku University, Institute of Fluid Science, Research Associate, 流体科学研究所, 助手 (50006178)
SOYAMA Hitoshi Tohoku University, Institute of Fluid Science, Research Associate, 流体科学研究所, 助手 (90211995)
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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 |
¥1,100,000 (Direct Cost: ¥1,100,000)
Fiscal Year 1992: ¥100,000 (Direct Cost: ¥100,000)
Fiscal Year 1991: ¥400,000 (Direct Cost: ¥400,000)
Fiscal Year 1990: ¥600,000 (Direct Cost: ¥600,000)
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| Keywords | Acoustic emission / Cavitation / Subcavitation / Supercavitation / Inception / Yield point / Fracture / Analogy / スーパキャビテーション / アコ-スティック・エミッション / キャビテ-ション / エロ-ジョン / 引張試験 / 材料の破壊 / 音響エネルギ / 振動壊食試験 |
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| Research Abstract |
In order to study the analogy between cavitation development and solid fracture processes, the number of AE pulses and the pulse-height distributions were measured by means of acoustic emission AE method, both in the cavitating flow past a fence and in tensile deformation of mild steel, with respect to cavitation aspects and stress-strain relation. The results are summarized as follows ;
(1) Cavitation process from the subcavitation state to the super-cavitation state is very similar to the solid fracture process, since both the number of AE pulses - cavitation number curve and the number - stress curve have two peaks in the critical state of the cavitation process and the fracture process.
(2) The AE signal at the 1st peaks in the highly cavitation number and the stress regions, is the successive burst-type, while the isolated burst-type signal takes place at the 2nd peaks in the lower cavitation number and stress regions. This fact suggests the similarity between them.
(3) The exponents calculated from the pulse-height distributions show the normal distribution near the inception and the end of the yield point. This fact is available to evaluate the analogy both processes.
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