Viscous Interaction Upstream and Downstream of a Turbine Stator Cascade With a Periodic Wake Field

Abstract

The influence of periodic rotor wakes has a substantial effect on the flow in a turbine stator cascade. A mechanism located upstream of a linear, low-aspect ratio, turbine cascade simulated wakes shed from rotor blades by translating cylindrical rods across the inlet of the cascade. In order to provide a test case to increase our fundamental understanding of the unsteady viscous flow typical of a gas turbine engine, three components of velocity, phase-locked into sixteen time windows which encompassed the rotor period, were measured at two upstream planes and one downstream plane. Due to the effects in the endwall region, the wake in the inlet plane bows in the tangential direction as the wake translates into the passage. The effects of the passage vortex do not decay significantly within one chord downstream of the exit of the cascade. The location of the passage vortex at the far downstream exit plane is dependent upon rotor position, as reported in earlier studies. A complete data set of the mean and fluctuating velocity components at all sixteen time windows is available on diskette.