The Probability Distribution of the Relative Highest Water Level in Surge Tank of Waterpower Station

In the operation of waterpower station, the randomness of numerous factors in water conveyance system including parameter of pipeline, boundary conditions and initial conditions determines that surge in the tank of water conveyance system is random in nature. To make a clear analysis of the working process of surge in tank, the stochastic model has to be set up to deal with the randomness of them. The stochastic model with both stochastically initial conditions and stochastically coefficients is established in the paper, and the stochastic analysis of surge in tank made. Besides, with pipe roughness and original load taken as random variables, probability density function of hydraulic head-loss and probability density function of maximum value of relative surge level are rigidly deduced and the results of the examples concerned agree completely with those from the Monte-Carlo method.