| Co-Investigator(Kenkyū-buntansha) |
SHIMAMOTO Akira Saitama Institute of Technology, Department of Mechanical Engineering, Professor (10118664)
JU Dong-Ying Saitama Institute of Technology, Department of Mechanical Engineering, Professor (10255143)
NEGISHI Riichiro Saitama Institute of Technology, Advanced Science Research Laboratory, Scientist (70237808)
ITO Yukio Hachinohe Institute of Technology, Faculty of Engineering, Professor (70006196)
IKOHAGI Toshiaki Tohoku University, Institute of Fluid Science, Director (90091652)
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| Research Abstract |
Supersonic behavior of cavitation bubble cloud developed along the highspeed submerged water jet, especially the occurrence mechanism of highly erosive singular vortex bubble, by which the peening effectiveness is most powerfully affected, systematically investigated, in order to surpass the fatal fatigue fracture on atomic reactor pressure-vessels.
As it has been recently reviewed by the writer, clearly, the highly erosive vortex cavitation of present interest is very sensitive to the cavitation nuclei Fortunately, as the nuclei are much dependent on water temperature, flow turbulence, vented air as well as separation region along the nozzle surface, in the present studies, therefore, their effectiveness is systematically, quantitatively evaluated, showing useful possibility to control the peening power effectively.
By means of highspeed photography, we can clearly observe the singular vortex bubble arisen under a deep cavitation cloud, so that we can find a direct method to specify the mechanism of such a water-jet-peening.
Finally, in order to establish economical method to make peening on several machine parts of very complex shape, we take up the herical gear set within a typical automobile torque converter, and systematically investigate residual stress distribution as well as cavitation shock pressure distribution, showing that this method is much effective against the curved surface.
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