A numerical simulation program is used to solve the steady separation flow in the hydraulic turbomachinery. Concerning the correction of the wall effect, the 2D unsteady N-S equations were solved with K-ε turbulence model. The measured vibration frequency of the power station equipments is different from that obtained by Karman vortex street theory. It might be because the incipient separation point moves forward when the flow volume decreases and the attack angle increases. In the flow separation zone, the investigated results also indicated the static pressure changes greatly along the direction of the main flow. The rate is nearly as same as that in the main flow. Compared with that of laminal flow separation, the structure of time-averaged turbulence flow separation is very different. The models of laminal flow separation are difficult to be adopted directly in the research of turbulent flow separation.
