Experimental Investigation on Influence of Incidence on Performance of Turbine Stator Cascade

An experimental investigation was carried out to examine the influence of incidence angle on the performance of an annular turbine stator cascade with controlled outlet angle guide vanes.The tests were made at seven incidence angles from +25° to -28°.The five hole probe measurements were performed at two planes,one was located at the stator cascade exit and another at the guide vane exit.The static pressure distribution on the stator blade surface was also measured.The distributions of local energy loss coefficients with local static pressure coefficients,as well as the secondary flow velocity vector plots show in detail,how much the losses and the secondary flow are influenced by incidence angles.At positive incidence,the losses rise mainly due to the development of passage vortex.At negative incidence,the losses rise due to the separation of pressure surface boundary layer.