长短叶片水轮机转轮内固液两相流数值模拟

运用RNGκ-ε湍流模型和两相流混合模型,分别对常规叶片和长短叶片的混流式水轮机全流道在不同开度下的含沙水流运动进行数值模拟,并对常规叶片转轮磨损情况与实验结果进行比较分析。对固体颗粒在2种转轮内的流动状况及叶片表面泥沙磨损程度进行分析时发现:2种转轮叶片表面泥沙颗粒速度曲线趋势相同,都是在叶片进口处存在速度最大值;在最优工况下,常规叶片表面的泥沙浓度要高于长短叶片,在叶片进口压力面和出口处出现了严重的泥沙磨损;长短叶片表面的泥沙浓度分布更为均匀。此外,在计算过程中还发现,叶片进口压力面的磨损程度随开度的减小而稍有加剧,最严重区域发生在距叶片进口1/5位置处。

Numerical simulation of two-phase flow through impeller of hydraulic turbine with splitter blades

Using RNG κ-ε turbulence model and the two-phase flow mixed model, the numerical simulation of the sandy water movement in the whole flow channel of mixed-flow turbine with general blades and splitter blades at different opening de-grees is conducted, and the wear condition of the impeller with general blades is compared with experimental results. Through a-nalysis of the movement of solid particles through two impellers and the wearing degree of the blade surface caused by the sedi-ments, the following conclusions are drawn:the speed curves of the sediments on the blade surface of the two impellers have the same trend in that the maximum values both appear at the inlets of the blades;In optimal working condition, the sediment con-centration on the general blades is higher than that of the splitter blades, serious sediment wear occurs to the inlet pressure sur-face and outlet of the blades. It is also founded by calculation that the wearing degree of the inflow pressure surface increases as the opening degree of the blades decreases, and the position at the 1/5 distance away from the inlet is where the most serious wear occurs.