某高转速汽轮机末级流场分析及通流优化

采用数值计算的方法,对某高转速汽轮机末级通流进行了流场分析,得到以下结论:叶顶区域产生了二次流及集中涡系,尤其是12级静叶叶顶区域产生了明显的通道涡、壁角涡;叶根、叶顶区域产生了明显的激波;不同攻角特征造成叶片壁面出现贯穿叶根、叶顶的流动分离,尤其是压力面流动分离使叶片入口产生负压区。通过上述分析,得到如下优化方法:确定11级静叶的最优安装角为50.5651°;增加11级叶片中径、增加11级与12级级间的轴向距离相结合的方法,以减小涡系强度。

Flow Field Analysis and Flow Passage Optimization of the Final Stage of a High Speed Steam Turbine

The flow field of the final stage of a high-speed steam turbine is analyzed by numerical calculation method,and the following conclusions are obtained.There are secondary flow and concentrated vortices in the tip region of blade,especially in the tip region of 12th stage stationary blade,which produce obvious passage vortices and corner vortices.Obvious shock waves are generated in theblade root andblade tip regions.The flow separation across the blade root and blade tip occurs on the blade wall due to different attack angle characteristics,especially the flow separation on the pressure surface causes the negative pressure area at the blade inlet.Through the above analysis,the following optimization method is obtained.The optimal installation angle of the 11th stage stationary blade is determined to be 50.5651°.The method of increasing the meridian of the 11th stage blade and increasing the axial distance between the 11th and 12th stage can reduce the strength of the vortex system.