STATOR ROTOR INTERACTION IN A TRANSONIC TURBINE

This paper presents calculations of a stator/rotor interaction in a highly loaded transonic first turbine stage.Of particular interest is the propagation and reflection of shocks which originate at the trailing edge of the upstream stator. These produce a 40% variation in the lift on the rotor, which would cause structural vibrations and increased losses. Also, the unsteady shocks would cause temporary boundary-layer separation near the leading edge of the suction surface. The numerical procedure solves the inviscid unsteady Euler equations, including quasi-three-dimensional terms. The use of a conservative treatment guarantees the correct treatment of the moving shocks. A simple technique is used to couple the calculations on the stator and rotor grids. A key feature of the paper is the use of "time-inclined" computational planes to allow the analysis of cases in which the ratio of stator and rotor pitches is not equal to unity or the ratio of two small integers. © 1990 American Institute of Aeronautics and Astronautics, Inc., All rights reserved.