【摘要】 大型水电工程的尾水隧洞中可能会发生明满交替流动,给电站过渡过程带来很大影响,需要建立合理可行的明满交替流动数值计算模型。针对常用的明满交替流动数值差分格式在明满流分界面通过计算节点时计算不稳定的问题,提出了一种新的计算方法——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。通过某电站尾水隧洞水工水力学模型实验专门对该方法进行验证,表明该计算方法是正确的。更多还原

【Abstract】 In tailrace tunnels of large hydropower station, a transient mixed free-surface-pressure flow may occur, which has a complex effect on the stability and transient of the power plant. It is necessary to build a global computer model that can detect and simulate the mixed free-surface-pressure flow. In this paper, a new method, namely Characteristic Implicit Method, with good stability based on implicit finite difference scheme has been proposed. Compared with other methods, the new method resolves the calculation instability when the interface of the mixed free-surface-pressure flow passed the computational node. The normal forms of the hyperbolic system made up of the continuity and momentum equations are used and differenced in this method. Model experiment for tailrace tunnel of hydropower station has been conducted and the results of this method agree with the experiment very well.更多还原