Experimental investigation on flowfields of non-axisymmetric endwall of annular cascades in multi condition

Aerodynamic performance of two kinds of annular turbine cascade with non-axisymmetric endwall profiling methods,which are designed by trigonometric function controlling method and pressure difference controlling method,was experimentally studied in the annular cascade wind tunnel test rig under designed condition and off-designed condition.The results show that some new characteristic are present under different flow conditions: amplitude of pressure distribution between pressure side and suction side is changing with different flow conditions,total pressure loss coefficient will decrease with increase of outlet Match number,secondary flow vector distribution will remain unchanged with outlet Match number,but the strength of secondary flow and passage vortex will decline with reduction of outlet Match number.