水口电站日调节不稳定流数值模拟

The Computer Simulation of Daily Regulating Unsteady Flows below Shuikou Hydro-power Station

用一维不稳定流数学模型模拟枯水期水口电站下游日调节不稳定流。选择Preissmann差分格式,把模型转化为有限差分方程组,并用“双扫描”法求解。依据水文气象资料,确定旁侧入流,用满宁方程反推糙率,并拟合了糙率随水深、流量变化的曲线。电站出流过程线、解放大桥水位过程线分别作为上、下边界条件,局部水头损失考虑了桥墩阻水和淮安分流的影响,在IBM-286机上实现了坝下长约72km河段内,日调节不稳定流的衰减过程的模拟运算。

The one dimensional model is employed to simulate the daily regulating unsteady flows below Shuikou reservoir. The finite-difference equations are formulated from Preissmann's implicit method, and solved by the double-sweep method. Lateral inflow is determined on the basis of the hydro-meteorological data. Manning's coefficients are obtained from field-mersured data by solving steady momentatum equation. Interior and exterior boundary conditions such as reservoir autflow, the variation of n with Q, Hui'an bifurcation, energy loss at bridge and downstream stage hydrograph are under consideration. The computations are performed using a time interval of 3 minutes for the sudden changes in discharge and a time interval of 57 minutes are used for the slowly varying parts of the flow. The numerical results achieved by using IBM-286 microcomputer.