Radial Migration of Shed Vortices in a Transonic Rotor Following a Wake Generator: A Comparison Between Time Accurate and Average Passage Approaches

Abstract

This paper shows a comparison of an unsteady simulation using turbo and an average passage simulation for a two blade row configuration consisting of a wake generator followed by a transonic rotor. Two spacings were simulated, both close and far. The unsteady results compare well with experiment especially for the profile of efficiency difference between close and far. An analysis of results helps to explain the unusual profile seen experimentally that is due to the radial migration of wake generator shed vortices with negative radial velocities near the tip. In addition, different components of the average passage body forces (deterministic stresses) are explored that shows the main terms are the axial momentum and the metal blockage.