非轴对称端壁透平级气动性能的数值研究

摘要

Nonaxisymmetric end wall profiling of a high loaded and low aspect ratio turbine stage was designed by the two control curves method.The characteristics of the initial axisymmetric end wall profiling turbine stage and the nonaxisymmetric end wall profiling turbine stage with high load and low aspect ratio were numerically investigated using the Reynolds-averaged NavierStokes (RANS) and the SST turbulent model with transition effects.The numerical results for the axisymmetric turbine stage and the nonaxisymmetric turbine stage were compared and analyzed.The results show that the nonaxisymmetric end wall reduces the circumferential pressure gradient and the secondary loss,and the efficiency of the end wall profiling stage increases by 0.16％,compared with that of the axisymmetric end wall stage.In addition,the inlet condition of the rotor changes due to the change in the stator flow field,resulting in the increase in the rotor inlet pressure and the reaction degree.%采用双控制型线方法对高负荷低展弦比透平级完成了非轴对称端壁造型设计;采用RANS方程和考虑转捩模型的SST紊流模型对轴对称端壁透平级和非轴对称端壁透平级进行了气动性能的分析和对比.结果表明:非轴对称端壁造型设计方法通过降低周向压力梯度减小了透平级的二次流损失,提高了透平级效率达0.16％;静叶流场的变化引起了动叶进口条件的改变,从而导致动叶进口压力和反动度增大.