通气空化多相流动特性的实验与数值研究

EXPERIMENTAL AND NUMERICAL STUDY ON CHARACTERISTIC OF VENTILATED CAVITATION MULTIPHASE FLOW

为了进一步分析通气空化多相流的特性,采用实验和数值模拟相结合的方法,对绕带空化器回转体的通气两相流动和通气三相流动的结构进行了对比分析。实验中采用高速全流场流动显示技术获得了通气空化多相流动的空泡形态;数值模拟中采用滤波器湍流模型(FBM)进行了数值计算,获得了空泡形态和流线分布,数值模拟获得的空泡形态与实验一致。结果表明,由于空化数的不同,在相同通气率下,绕回转体通气空化三相流动的空泡形态不同于通气两相流动;同时空泡的非定常行为也发生了大的变化。

To analyze the characteristic of ventilated cavitation multiphase flow, The structures of the ventilated cavitation three-phase flow and ventilated cavitation two-phase flow around an axisymmetric body with a cavitator are addressed by experimental and numerical simulation methods. Cavity shapes were measured by high-speed flow visualization technology in different cavitation numbers. The distributions of streamline and cavity shapes were obtained by a filter-based model（FBM）, and a good agreement is obtained between experimental data and numerical simulations. The results show that when the ventilated rate is constant, the cavity shape is different between ventilated cavitation two-phase flow and three-phase flow at different cavitation numbers, and that the unsteady characteristics of cavity are great changed at the same time.