为了研究通气超空泡初生及发展过程中空泡形态及泄气模式的演变特性,采用分相流模型和SST湍流模型,考虑通气压缩性和重力效应,建立了通气超空化三维数值计算模型,并通过试验数据进行了校核和验证,研究了在通气率和弗劳德数大范围变化下的通气超空泡生成及发展过程.结果表明:回射流模式超空泡发展过程非常不稳定,空泡初生时伴随空泡的断裂及分离,空泡发展过程中存在气/水混合物回流现象,超空泡形态难以预估.双涡管模式超空泡先以回射流模式发展,当超空泡充分发展后,空泡闭合模式转变为双涡管方式,空泡形态及泡内压力相对比较稳定.接近超空泡泄气转变临界时,超空泡闭合模式在双涡管和回射流之间相互转变,导致超空化流动及超空泡形态变化更加复杂.

To study the variation characteristic of supercavity shape and gas-leaking mode in the initial generation and development process of a ventilated supercavity, a 3-D numerical model considering the compressibility of the ventilated gas and gravity effect was adopted to simulate the supercavitation flow by using the inhomogeneous multiphase flow model and the SST turbulence model, which is verified and validated by the experimental results. The process of initial generation and development of the ventilated supercavity were investigated over a wide range of air entrainment coefficients and Froude numbers. The results show that the development of the re-entrant jet supercavity is very unstable. The initial generation of the supercavity is accompanied by the cavity collapse and cavity shedding, the phenomenon of air-water mixture reversely flowing occurs in the devolopment of the supercavity, and the supercavity shape is difficult to be estimated. The twin vortex supercavity is initially developed by the re-entrant jet closure mode. Then, the supercavity closure mode transfers to the twin vortex after the supercavity is fully developed, and the supercavity shape and the internal pressure are relatively stable. When approaching the criteria for the formation of the twin vortex and re-entrant jet closure, the supercavity mode changes between the twin vortex and the re-entrant jet, resulting in a more complex variation of supercavitation flow and supercavity shape.