CFD Prediction of Unsteady Pressures due to Fan Rotor-Stator Interaction

摘要

Unsteady three-dimensional Navier-Stokes analyses are performed to predict the unsteady pressures induced by rotor viscous wakes on stator vanes. The primary object of this study is to investigate the effects of axial spacing between the rotor and the stator and threedimensional vane geometries such as stator sweep and stator lean on the unsteady pressure fluctuations on the stator vane. Five different stator configurations with three sets of stator geometries, which are three radial stator configurations with different axial spacing, the swept stator and the swept and leaned stator, are used for this study. A three-dimensional analytical method using unsteady lifting-surface theory is also used to elucidate the mechanism of interaction of passing rotor wakes with downstream stator. It is found that, in axial spacing between rotor and stator, the effect of radial phase skew of incoming rotor wake is important for the reduction in the induced unsteady pressure. It is also shown that incorporation of stator sweep and lean is effective to obtain a significant reduction in the induced unsteady pressure.