キャビテーションを伴う噴流の衝突による壊食

第2報 : 噴流出口周りおよび衝突面形状の影響

抄録

Cavitation erosion produced by impingement of a cavitating jet was experimentally studied using aluminum alloy specimens in tap water. The effects of nozzle holder and configuration of the impingement surface on mass loss were investigated. Furthermore, numerical simulations of two-dimensional jets were conducted to clarify the effects of the nozzle holder, i.e., the configuration around the nozzle outlet.
Main points of interest are as follows :
(1) The erosivity of the cavitating jet is enhanced significantly by the restrictive wall around the nozzle outlet. The numerical simulation of the two-dimensional jet shows that the restrictive walls on both sides of the nozzle outlet lower the pressure near the nozzle outlet, changing its flow structure. For that reason, the restrictive wall favors cavitation to occur.
(2) The erosivity of the cavitating jet is also affected significantly by the configuration of the impingement surface.