A QUASI UNSTEADY STUDY ON WAKE INTERACTION OF TURBINE STATOR AND ROTOR CASCADES

Detailed flow measurements were made to study cascade interaction of t urbine stator and rotor, using two linear cascades installed in series . The upstream cascade was moved to several places in the cascade pitc hwise direction in order to change the relative location between the t wo cascades, and measurements were mane in the downstream cascade. The result shows that the net total pressure loss generated in the downst ream cascade becomes maximum when wakes of the upstream cascade pass t he suction side of the downstream cascade passage, while the tip leaka ge loss generated in the downstream cascade does not change with the r elative location of the cascades. The upstream cascade wakes interact with the secondary flows and most strongly with the endwall flow in th e downstream cascade passage, making the loss distributions in the cas cades fairly unsteady.