转轮表面糙度对水泵水轮机泵工况水力性能的影响

Influence of roughness of runner on the cavitation of pump-turbine in the pump mode

本文研究了转轮叶片过流表面粗糙度对水泵水轮机泵工况下效率与空化的影响。采用对数律壁面函数与三维定常k-ε湍流模型相结合的方法,在考虑粗糙度影响的基础上,对水泵水轮机模型转轮泵工况下的内部流场进行了模拟,并对模拟结果进行了分析;利用转轮内部流场数据与微观粗糙表面简化物理模型,采用多相流模型对局部粗糙叶片表面做微观流场分析。研究结果表明:粗糙度对转轮效率与空化均有影响,表面粗糙度值越大,效率下降越多,叶片表面上的空化数越大,以此推断叶片表面越易发生空化。

This paper introduces the influence of roughness of runner on the efficiency and cavitation of pump turbine under pump operating condition. Considering the effect of the roughness, the log law of the wall function and 3D steady κ-ε turbulence model are used to simulate the inner flow of the pump-turbine runner under the operating condition. Based on the result of the runner simulation and the simplified physical model of local micro- rough surface of the blade, the cavitation model of muhiphase flow is Lapplied to simulate the flow on the surface of the local blade. Some results are obtained that roughness affects the efficiency and cavitation of the pump-turbine, the efficiency decreases when roughness value increases. Similarly, when the cavitation number of the blade surface increases, the roughness value and the water-vapor near the blade surface also increase which leads to the incipient cavitation.