液力透平的数值计算与试验

设计了液力透平试验台,对一单级液力透平进行了试验,得到了外特性曲线.采用全流场和结构化网格技术对液力透平内部流动进行了数值计算.分析了液力透平在不同流量下的压力场和速度场,得到了内部流场的分布规律.应用速度三角形对液力透平叶轮和尾水管内部速度场随流量变化规律进行了研究.结果表明:离心泵反转可用作透平运行,并具有较高的效率；最高效率的数值计算与试验结果相对误差为4.85％；透平内部的压力从蜗壳进口经叶轮到尾水管逐渐减小,进出口压差随流量增加而逐渐增加；在透平叶片背面和工作面存在漩涡区域,漩涡位置和区域大小随流量而变化；在尾水管横截面上存在的圆周速度分量随流量而变化.

Numerical calculation and experiment of hydraulic turbine

A test rig for single stage hydraulic turbine was designed to obtain extra performance curves through experiment.Numerical simulation of the designed hydraulic turbine was performed by all domains and structural mesh technique.The pressure field and velocity field at different flow rate were discussed to acquire flow field distribution within hydraulic turbine.The variation of velocity field within turbine impeller and outlet pipe at different flow rate was analyzed according to velocity triangle.The results show that a centrifugal pump can run reversely as high efficiency turbine without any modification.The relative error at the best efficiency between numerical calculation and experimental results is 4.85%.The absolute pressure within hydraulic turbine decreases gradually along the volute,impeller and outlet pipe,while the pressure difference between inlet and outlet increases with the increase of flow rate.Vortex regions are located at impeller blade suction and pressure side with location and region size varied by flow rate.The absolute tangential velocity at outlet pipe section is varied with flow.