直接加圧方式アブレシブジェットの流動構造とせん孔特性に及ぼすノズル形状の影響 (<小特集>混相流の数値シミュレーションと新技術)

抄録

Experimental studies are carried out to clarify the effect of nozzle shape on the structure and drilling capability of a premixed abrasive water jet in air. Flow visualization and erosion results are obtained with the use of five different nozzles: four conical nozzles with different length focus sections and a quarter circle entrance nozzle with a focus section. Erosion tests are conducted on stainless steel specimens at an injection pressure of 11.9MPa. Aluminum oxides with different grain sizes, #100 and #220, are used as abrasives. The structures of the jets are observed using instantaneous photographs. The optimum nozzle shape is determined through erosion tests and observation of the jets.