基于逆向设计理论的水泵水轮机设计与数值模拟

针对水泵水轮机效率普遍较低这一问题,借鉴低比转数混流式水轮机的叶片设计理论,对一给定参数的水泵水轮应用水轮机逆向设计理论对水泵水轮机进行水力设计、三维造型和ICEM网格划分;通过建立相对坐标系下的时均连续方程及N-S时均方程等控制方程组,利用标准k-ε湍流模型来封闭方程组,采用有限元体积法进行离散,离散方程的压力-速度耦合处理采用压力耦合方程组的半隐式(SIMPLEC)算法对水泵水轮机进行数值计算,得到其内流场流动特性,与试验的水泵和水轮机工况下压力分布对比分析,预测了水泵水轮机在设计工况下的转轮效率.数值模拟结果表明,基于逆向设计理论设计的水泵水轮机工况的最优效率可以达到91%,水泵工况的最优效率达到82%,充分说明应用逆向理论设计方法对水泵水轮机的设计,可以兼顾水泵工况和水轮机工况在较优的情况下运行.

Pump-turbine runner design and flow simulation based on inverse design method

As pump-turbines are usually subject to a poorer efficiency,through drawing lessons from the blade design principle for low specific speed Francis turbines,the blades in a pump-turbine runner were designed by using inverse design method under given design duty parameters,and then 3D modeling and ICEM meshing were carried out. The flow field in the pump-turbine was simulated and the flow characteristics were identified by solving the RNG k-ε turbulence model and N-S equations in the relative coordinate system. The finite volume method was used to discrete fluid domain and SIMPLEC algorithm was applied to couple the N-S equations. The efficiency of the pump-turbine was predicted as well. A comparison of predicted and experimental pressure distribution has been conducted. The numerical results show that the best efficiency can reach as high as 91% with turbine mode and 82% with pump mode,respectively.This demonstrates that the inverse design method can take both pump and turbine modes into account in hydraulic design to make a pump-turbine be operated in a relatively optimal condition.