A cavitating venturi in the auxiliary feed water system of a nuclear power plant is a flow control device that limits the maximum flow rate in critical conditions. In this research, a numerical study was conducted to predict the characteristics of the cavitating flow in a venturi with various geometrical configurations. Assuming axisymmetric geometry and a steady state, equations of the flow field were solved numerically. The mixture model for the multi-phase flow and the standard k-ε turbulence model were adopted. The primary diffuser angle was varied to perform detailed parametric study. The flow and pressure variations, shape of the cavitation bubble, and corresponding flow control characteristics were summarized. Finally, the calculation results were analyzed to provide a physical basis for the design limits proposed in a previous patent. It is expected that the results of this study will be useful information for the future design of an optimized venturi.

核电厂辅助给水系统中的空化文丘里管是一种流量控制装置，可限制关键条件下的最大流量。在这项研究中，进行了一项数值研究，以预测具有各种几何构型的文丘里管中空化流的特征。假定轴对称的几何形状和稳态，则用数值方法求解流场方程。采用了多相流的混合模型和标准的k-ε湍流模型。改变主扩散器角度以进行详细的参数研究。总结了流量和压力的变化，空化气泡的形状以及相应的流量控制特性。最后，对计算结果进行了分析，为先前专利中提出的设计限制提供了物理基础。