A fully conservative sharp-interface method is developed for multiphase flows with phase change. The coupling between two phases is implemented via introducing the interfacial fluxes, which are obtained by solving a general Riemann problem with phase change. A novel four-wave model is proposed to obtain an approximate Riemann solution, which simplifies the eight-dimensional roo-finding procedure in the exact solver to a sole iteration of the mass flux. Unlike in the previous research, the jump conditions of all waves are imposed strictly in the present approximate Riemann solver so that conservation is guaranteed. Different choices of the fluid states used in the phase change model are compared, and we have shown that the adjacent states of phase interface should be used to ensure numerical consistency. To the authors' knowledge, it has not been reported before in the open literature. With good agreements, various numerical examples are considered to validate the present method by comparing the results against the exact solutions or the previous simulations.

翻译：为具有阶段变化的多阶段流动制定了一种完全保守的尖锐界面方法。两个阶段之间的连接是通过引入中间通量来实现的,这些通量是通过解决里曼对阶段变化的一般问题获得的。提出了一个新的四波模型,以获得近似里曼的四波解决方案,该模型将八维调查程序简化在精确的求解器中,简化为质量通量的唯一迭代。与以往的研究不同,所有波的跳跃条件严格地强加在目前近似里曼的求解器中,以保证保护。对阶段变化模型中使用的流体状态的不同选择进行了比较,我们已表明应使用相邻的阶段界面状态来确保数字一致性。据作者所知,以前没有在公开文献中报告过。根据良好的协议,通过将结果与确切的解决方案或先前的模拟进行比较,可以考虑各种数字实例来验证目前的方法。