Experiment on aerodynamic performance of turbine static cascade with high aerodynamic loading

In a low-speed ring cascade wind tunnel,aerodynamic tests were fulfilled on a large enthalpy drop static cascade in the middle stage of a steam turbine.From the front to the back gate,the flow parameters in seven cross sections along the blade height and pitch at three incidences were measured in detail with the application of five-hole pin ball test.The results show that,in order to meet the requirements of high loading conditions,the combination of highly variable loading and blade bending along span-wise can control the accumulation,transition and separation of boundary layer.Fore-loaded blade profiles were applied in the main passage area to ensure that the blade could withstand high loading.After-loaded blade profile was applied to the end wall and the positive bending blade further reduced aerodynamic loading,the end wall lateral pressure gradient was cut down to weaken the end wall lateral secondary flow.Positive and negative incidences affect only the static pressure distribution at the leading edge of the suction side or pressure side,causing the increase and decrease of aerodynamic loading.The turbine cascade with high aerodynamic loading has a good adaptability of incidence.