| Budget Amount *help |
¥4,680,000 (Direct Cost: ¥3,600,000、Indirect Cost: ¥1,080,000)
Fiscal Year 2019: ¥1,300,000 (Direct Cost: ¥1,000,000、Indirect Cost: ¥300,000)
Fiscal Year 2018: ¥1,560,000 (Direct Cost: ¥1,200,000、Indirect Cost: ¥360,000)
Fiscal Year 2017: ¥1,820,000 (Direct Cost: ¥1,400,000、Indirect Cost: ¥420,000)
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| Outline of Final Research Achievements |
High-speed abrasive suspension jet (hereafter ASJ) shows a peculiar processing property but it decreases quickly under submerged condition. Aimed to establish an effective method for submerged cutting, high-speed video observation on the flow structure of air ventilated jets was carried out and a ventilation nozzle system to generate air coated jet in submerged condition has been developed. Air coated jets pulsate periodically, and the dominant frequency of jet pulsation decreases with the increase of ventilation flowrate. Strouhal number st defined by the dominant frequency depends upon an altered cavitation number σ_(sh) defined by the pressure in sheath. When σ_(sh)=0.0005 at an appropriate ventilation flowrate, stable cavities of 20~30d in length covering the jet are formed. Cutting tests show that the relative kerf of submerged cutting reaches to nearly one within this range of standoff distance and an equal processing ability of the cutting in air is demonstrated.
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