Cavitation frequently arises in the safety valve of nuclear power plants’ secondary circuits operating under high pressure conditions. This study integrates valve flow characteristics and velocity strain rate corrections into the Zwart-Gerber-Belamri model to accurately simulate cavitation inside the valve, reducing the impact of physical empirical coefficient variations on cavitation length prediction. Subsequently, a visualisation test rig is developed to validate the accuracy of the numerical model, and experimental cavitation results are obtained using the grayscale detection method. The evaporation/condensation coefficients are optimised using the AES-MSI model and GA based on the experimental results. The accuracy of the constructed model is validated by comparing it with experimental results obtained under various operating conditions. Finally, the high-fidelity numerical model is employed to investigate the effects of pressure drop and valve openings on cavitation, elucidating the underlying mechanisms governing cavitation variations resulting from pressure drops. Furthermore, a comprehensive equation is derived to determine the effective flow area, aiding in the identification of cavitation locations and offering insights into the relationship between cavitation behaviour and valve openings. The modified cavitation model proposed in this study can be readily extended to investigate cavitation prediction in other valves or throttle elements.

在高压条件下运行的核电站二回路安全阀经常出现气蚀现象。本研究将阀门流动特性和速度应变率修正集成到Zwart-Gerber-Belamri模型中，以精确模拟阀门内部的空化，减少物理经验系数变化对空化长度预测的影响。随后，开发了可视化试验装置来验证数值模型的准确性，并使用灰度检测方法获得了实验空化结果。根据实验结果，利用AES-MSI模型和遗传算法对蒸发/冷凝系数进行优化。通过与不同操作条件下获得的实验结果进行比较，验证了所构建模型的准确性。最后，采用高保真数值模型研究压降和阀门开度对空化的影响，阐明控制压降导致的空化变化的基本机制。此外，还导出了一个综合方程来确定有效流动面积，有助于识别空化位置并深入了解空化行为与阀门开度之间的关系。本研究中提出的改进的空化模型可以很容易地扩展到研究其他阀门或节流元件中的空化预测。推导出一个综合方程来确定有效流动面积，有助于识别空化位置并深入了解空化行为与阀门开度之间的关系。本研究中提出的改进的空化模型可以很容易地扩展到研究其他阀门或节流元件中的空化预测。推导出一个综合方程来确定有效流动面积，有助于识别空化位置并深入了解空化行为与阀门开度之间的关系。本研究中提出的改进的空化模型可以很容易地扩展到研究其他阀门或节流元件中的空化预测。