在水电站的仿真计算中 ,建立合理可行的明满混合流动数值模型是必要的。针对现有明满混合流动的数值解法中存在稳定性差的缺点 ,提出了一种新的计算格式——特征隐式格式法。其主要思路是将动量和连续方程转化为双曲型方程组的标准形式进行差分。该方法用于三峡、百色等大型电站的仿真计算中 ,计算结果合理可信。文中还研究了洞型对流动特性的影响 ,提出了发生明满混合流动的隧洞的优化设计原则 In the simulation calculation of hydropower station, it is necessary to establish a reasonable and feasible numerical model of full-bloom mixed flow. Aiming at the shortcoming of the poor stability of the existing full-bloom mixed numerical solution, a new computational format, the characteristic implicit format method, is proposed. The main idea is to differentiate the momentum and continuous equations into the standard form of hyperbolic equations. The method is used in the simulation of large power stations such as the Three Gorges and Baise, and the results are reasonable and credible. In the paper, the effect of cavity on the flow characteristics is also studied, and the optimal design principle of the tunnel with full and full flow is proposed