空泡溃灭水锤的VOF计算方法

空泡溃灭水锤是核电厂冷却循环系统中较常出现的一种严重的水锤事故。空泡的形成和溃灭是复杂的两相、瞬态过程，对于这一现象的分析是相当困难的。作者尝试着把蒸汽泡的边界看成是冷水流动的自由面，在自由面上考虑蒸汽的凝结。对于自由面的ＶＯＦ算法用了ＶＯＦ算法，取得了令人满意的结果，不仅形象地描绘了空泡的形成和溃灭的过程，而且得到了与实验相符的空泡溃灭高压和弥合速度，因此可为管道设计提供理论基础。

THE CALCULATION OF WATER-HAMMER CAUSED BY CAVITY COLLAPSING WITH VOF METHOD

The most serious water-hammer is caused by cavity collapsing in the coolant systems of Nuc-lear Power Plant.The process of cavity forming and collapsing is rather complicated with two-phase flow and transient state. It is very difficult to describe this process. In order to solve theproblem,the cavity is treated as free surface and water as viscous fluid with a variable boundary.For calculating the free surface,the VOF method is used and the condensation of vapor at the sur-face is considered.With this method, not only the cavity can be vividly described for forming andcollapsing,but also the highest pressure and closing velocity can be gotten. The results of calcula-tion are compared and are coincided with the results from the experiment in the laboratory.So itcan supply the theoretical foundation for designing pipeline.