基于有限体积法的有压管道水锤计算

在水电站运行过程中,为了避免机组增减负荷产生的水锤威胁输水系统的安全,需要对有压管道中的水锤进行精确的模拟计算。基于有限体积法对有压管道水锤方程分别进行空间和时间尺度上的积分,并采用隐式的Crank-Nicolson格式对偏微分项进行处理,从而得到了具有二阶精度且无条件稳定的水锤方程离散格式。通过算例比较了该离散格式与特征线法的计算结果,结果表明,新推导的离散格式在计算有压管道水锤问题时具有较高的精度且稳定性较好。

A Finite Volume Method for Water Hammer Calculation in Pressure Pipes

In order to avoid water hammer for threating the security of water conveyance system caused by unit load change in operation of hydropower station, it is necessary to simulate water hammer of pressure pipes. This paper uses finite volume method to integrate water hammer equations of pressure pipes on spatial and temporal scales. And then the implicit Crank Nicolson format is applied to handle the partial differential term. Thereby, second order accuracy and unconditionally stable discrete formats of water hammer equations are obtained. Compared FVM discrete formats with MOC, the results show that the new discrete formats have high accuracy and stability for calculation of water hammer in pressure pipes.