不同压力速度耦合模式下水轮机三维CFD计算对比

为研究在水轮机数值计算中不同的压力与速度耦合模式对水轮机内流场的影响。对作为研究对象的水轮机进行全流道三维建模及CFD计算。分别在流道蜗壳、转轮、尾水管内设置测点,计算在设定工况下不同压力速度耦合的流场及测点压力脉动数据。分析结果表明:PISO与Simple压力速度耦合模式下流场速度场分布相似,压力分布差异巨大,PISO模式下压力脉动为高频,Simple模式下为低频,其中Simple模式计算与实际符合较好。

Comparison of Three-Dimensional CFD Computation of Hydraulic Turbine under Different Pressure and Velocity Coupling Mode

For the purpose of studying the influence in the pressure and velocity coupling mode of water turbine numerical computation, the three-dimensional model of water turbine units has been established. Measure points are located in volute,runner and draft tube. Through the calculation, the data of flow field and pressure fluctuation are acquired. The result indicates that under the Piso and Simple mode with pressure and velocity coupling, the velocity field distribution is small, but the pressure field has a great many difference. Pressure pulsation in Piso model is high frequency, on the contrary, it is low frequency in simple model. The calculation result simple model is agree with actual situation.