Influence of Shock Wave on Behavior of Tip Leakage Flow in Axial Turbine Linear Cascade

Abstract

In this study, the transonic flows in the linear turbine cascade with the blade profile for high pressure turbine rotors were analyzed numerically by using the commercial CFD code with the assumption of steady compressible turbulent flow. The effects of the development of shock wave caused by the increase of exit Mach number on the tip leakage flow behavior were examined. The isentropic exit Mach number was varied from the subsonic to the supersonic conditions as an outlet boundary condition. The computed results clarified that the trajectory of tip leakage vortex was deflected in the spanwise direction toward the casing wall by the suction side shock wave at the trailing edge. Moreover, the increase of the obliqueness of the shock wave reduced the deflection.