突变流道内空泡脱落特性及空蚀损伤分析

针对一种特殊设计的空化室内空化演变过程进行数值模拟分析,利用流体汽化体积分数验证了雷诺应力湍流模型(RSM)、ZGB空化模型、增强壁面函数对于模拟空化过程的适用性,及其模拟结果与实验结果的吻合性;分析了流场分布特点和泡状空化下的空泡演变规律,并考察了壁面的空蚀损伤特性.结果表明,空化室内的空化演变是一个具有准周期性的非...

Cavitation Shedding Characteristics and Cavitation Damage Analysis in Sudden Change Channel

The numerical simulation of cavitation evolutionprocess in a special cavitation chamber was carried out, and the applicabilityof RSM turbulence model, ZGB cavitation model and enhanced wall function wereinvestigated by using the vaporation volume fraction of cavitation chamber. Theflow field distribution characteristics and cavitation evolution law underbubble cavitation were analyzed, and the cavitation damage characteristics ofwall were investigated. The results show that the cavitation evolution in thecavitation chamber is a quasi-periodic unsteady process, and the primary attachmentpoints of cavitation are closely related to the structure of the flow passage,and they are all at the maximum velocity of upstream flow. The cavitationdevelopment characteristics from different initial attachment position aremainly reflected in the large difference of vaporization volume fraction.However, their evolution cycles are close, their evolution laws are consistent,and their evolution processes are seriously affected by the flow field andchannel structure. The periodic evolution of cavitation makes the wall shearstress also showing periodic characteristics. It is found that the cavitationdamage degree has a peak value, which is closely related to the falling off,fusion and collapse process of cavitation mass.