基于ANSYS Bladegen软件,针对不同叶片安放角变化规律分别设计3种前弯叶片液力透平专用叶轮。通过与试验结果对比,确定了合理的数值模拟方案,分别完成了3台透平全流场数值计算。分析了叶片安放角变化规律对透平外特性、压力分布和水力损失分布的影响。结果表明:最优工况时,3个叶轮的效率、压力分布和水力损失分布均相差不大。在非最优工况,安放角采用线性变化规律设计时,透平性能更好,效率曲线更平坦;叶轮出口处低压区域范围较其他2种方案大。水力损失分布显示在叶片进出口安放角及包角相同的情况下,安放角变化规律对蜗壳及尾水管内的流动影响不大,仅对叶轮内的流动产生较明显的影响,叶片安放角呈"S"形变化对透平性能的影响是负面的,线性分布规律相对较好。
A special impeller with forward curved blades can improve the performance of pump as turbine( PAT). From the point of turbine working condition,blade inlet angle at leading edge was determined using shockless inlet flow,while its outlet angle was designed with non-swirling outflow. The distribution rule from inlet angle at leading edge to outlet angle at trailing edge is one of the main factors in impeller design. Therefore, an investigation on the distribution rules of blade angles influencing PAT's performance is useful. In order to investigate the effects of blade angle distributions on the performance of PAT with forward curved blades,three special impellers with different blade angle distributions were designed by using ANSYS Bladegen software. The validity of numerical simulation was first confirmed through the comparison between numerical and experimental results. The impellers with the same blade inlet, outlet angles and different blade angle distributions were numerically investigated. The performance,pressure distributions and hydraulic loss distributions within PATs were analysed. The results showed that under the optimal working condition,the differences of three PATs impeller in terms of efficiency,pressure distributions and hydraulic loss distributions were minor. Under non-optimal working conditions,when the angle distribution was linearly changed,the performance curve was moreflat and the low pressure area at the outlet of the impeller was larger than those of the other two PATs.Hydraulic loss distribution analysis illustrated that the influence of blade angle distributions on impeller was larger than those of volute and draft. Linear distribution had positive influence while "S"shaped change of angle distribution had negative influence on PATs performance.