| Project/Area Number |
07555333
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| Research Category |
Grant-in-Aid for Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Section | 試験 |
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| Research Field |
資源開発工学
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| Research Institution | Kumamoto University |
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Principal Investigator |
SUGAWARA Katsuhiko Kumamoto Univ., Civil Eng., Professor, 工学部, 教授 (60109668)
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| Co-Investigator(Kenkyū-buntansha) |
OBARA Yuzo Kumamoto Univ., Civil Eng., Associate Professor, 工学部, 助教授 (50135315)
岡村 宏 熊本大学, 工学部, 教授 (40040373)
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| Project Period (FY) |
1995 – 1996
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| Project Status |
Completed (Fiscal Year 1996)
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| Budget Amount *help |
¥3,800,000 (Direct Cost: ¥3,800,000)
Fiscal Year 1996: ¥1,000,000 (Direct Cost: ¥1,000,000)
Fiscal Year 1995: ¥2,800,000 (Direct Cost: ¥2,800,000)
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| Keywords | Water jet technology / Abrasive jet / Impact force measurement / Water jet cutting / Incident velocity of water jet / Velocity of erosion / ォータージェット / 壊食効果 / 入射速度 |
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| Research Abstract |
Practical use of high pressure water jets as a tool for rock cutting and drilling has become seriously accepted within the last decade, and the water jet technology is in the improvement stage for practical application. Then, the interest in the cutting mechanism is growing greater, and the precise method to evaluate the structure of water jets impinging onto the rock surface is required for the clarification of the fracture mechanism of rock.
In this research, the impact force that is the resultant force imposes upon a solid target by water jet impinging normally is analyzed to estimate the characteristics of water jet. The obtained results are as follows :
1) The mean velocity of incident jet is determined from the time-average of the impact force measured using a flat target of erosionless, based on the low of momentum.
2) The center depth in the surface erosion period is clarified to increase in direct proportion to the time of impinging, and the erosion speed is proportional to the 6th power of the incident velocity.
3) The theory and experiments shows that the depth of the slot is a function of the nozzle diameter, the driving pressure, the time of exposure, the pressure attenuation constants and the standard erosion pressure that characterizes the objective materials.
4) The erosion speed is proportional to the kinematic energy for ductile materials such as metals, and proportional to the momentum for brittle materials such as fine ceramics.
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