基于Rayleigh-Plesset方程的空化模型改进与应用  

Improved Cavitation Model Based on Rayleigh-Plesset Equation and Its Application

作　　者：洪锋 高振军 袁建平[3] 

机构地区：[1]三峡大学机械与动力学院,宜昌443002 [2]三峡大学水电机械设备设计与维护湖北省重点实验室,宜昌443002 [3]江苏大学国家水泵工程技术研究中心,镇江212013

出　　处：《农业机械学报》2018年第2期126-132,共7页Transactions of the Chinese Society for Agricultural Machinery

基　　金：国家自然科学基金重点项目(51239005);"十二五"国家科技支撑计划项目(2015BAD20B01)

摘　　要：为了提高Schnerr-Sauer模型预测空化流场的能力,提出了一种修正的球形空泡动力学模型,结合均相流假设建立了一种基于Rayleigh-Plesset方程的改进空化模型。联立修正后的滤波器湍流模型,分别采用改进后空化模型和Schnerr-Sauer模型对绕二维Clark-Y型水翼非定常空化流动进行计算,得到了不同空化数条件下翼型吸力面上空穴形态随时间变化规律及水动力系数特征。与已有文献的实验结果进行对比分析,结果表明:在准静态片状空化阶段,改进的空化模型计算得到的片状空穴长度基本上维持不变,在空穴尾部捕捉到明显的相间界面,与实验描述较为一致;在云状空化阶段,改进的空化模型模拟的空化区域范围更广,预测的瞬时升力系数与实验值的变化趋势吻合程度更高,且其对云空化周期性演变过程中一些流动细节的预测能力更好。With the aim to enhance the capability of predicting cavitating flows for Schnerr-Sauer model,a developed cavitation model was proposed based on an improved spherical bubble dynamic model and the homogeneous flow assumption. In particular,the terms of the second derivative of bubble radius and surface tension were also considered in the simplified Rayleigh-Plesset equation to give more reliable physical model for bubble shrink and growth. Unsteady and turbulent cavitating flows over a twodimensional Clark-Y hydrofoil were calculated by using the proposed model and Schnerr-Sauer model in which a modified filter-based model was adopted for the turbulence modeling. The cavity shape evolution and the characteristics of hydrodynamic coefficient at different cavitation numbers were obtained from simulations. Comparing with available experimental data in the literature, for quasi-static sheet cavitation,the length of the sheet cavity as predicted by the proposed model almost remained unchanged and noticeable vapor-liquid interface was captured at the rear of the sheet cavity as well,which agreed better with the experiment description. For the periodic cloud cavitation,the cavitation area predicted by the proposed model was larger than that of the Schnerr-Sauer model,which was induced by the noncondensable gas and turbulence fluctuation considered in the proposed model. Moreover,the transient lift coefficient predicted by the proposed model agreed better with the experimental data and the proposed model had better capability than the Schnerr-Sauer model to predict some detailed features of the cyclic cavity evolutions in cloud cavitation. The overall results proved the reliability and accuracy of the improved cavitation model in cavitating flow simulations over a hydrofoil.

关 键 词：空化 水翼 Rayleigh-Plesset方程 空化模型 数值计算 

分 类 号：O427.4[理学—声学]