一种修正的低温流体空化流动计算模型

为了更准确地预测低温流体的空化流动特性, 基于Kubota空化模型, 对蒸发和凝结源项进行修正, 建立了一种考虑热力学效应的空化模型. 分别采用原始和修正的Kubota空化模型, 计算了绕对称回转体液氮的空化流动, 通过与实验结果的比较对修正的空化模型进行了评价. 结果表明, 与原Kubota空化模型比较, 修正的空化模型由于考虑了热力学效应, 计算获得的蒸发量减小, 凝结量增大, 空穴长度减小, 空穴界面形态呈模糊状态.计算结果与实验结果更加一致, 说明修正的空化模型能准确的描述低温流体空化过程的质量传输过程, 能够更准确模拟低温流体中的空化流动特性. 

A MODIFIED KUBOTA CAVITATION MODEL FOR COMPUTATIONS OF CRYOGENIC CAVITATING FLOWS

In order to predict the cavitating flow characteristics in cryogenic fluids more exactly,a revised cavitation model considering the thermal effect with modified the evaporation and condensation source terms is established,which is based on Kubota cavitation model.The computations for cavitating flows in liquid nitrogen are conducted around an axisymmetric ogive by employing Kubota cavitation model and the revised cavitation model,respectively.The computational results are compared with the experimental data to evaluate the revised cavitation model.It is found that for the results of the revised cavitation model due to considering the thermal effects,the evaporation becomes smaller and the condensation becomes larger,the cavity length is shorter and the cavity interface becomes more porous compared with the results of original Kubota model.The results of the revised cavitation model are more accordant with the experimental data,and it dictates that the revised cavitation model can describe the process of mass transport more accurately in the cavitation process in cryogenic fluids and it is applicable for computations of cavitating flows in cryogenic fluids flow.