Detailed understanding of the flow interaction within the complex geometry of turbine stage coupled with the imposed unsteady pressure waves was presented. A fully validated numerical model was established based on ANSYS CFX code. For this purpose

four unsteady simulations of 20

40

60 and 80 Hz together with the steady state simulations were conducted. The flow angle distribution in a pulsating cycle and at the circumferential and spanwise positions was analyzed in different pulsating frequency conditions. The results showed that the pulsating frequency mainly affected the inlet incidence angle of rotor at the high pressure side

moreover

the lower the pulse frequency

the greater the negative incident angle of the low pressure side. It was also found that the absolute flow angle distribution at circumferential potion was similar and the relative flow angle fluctuations during the pressure decrements instances was significantly lower as compared with that during pressure increment instances.