Numerical investigation of plasma actuator induced forcing direction on the performance of a low-speed isolated axial compressor rotor

Abstract

This paper investigates the effects of changing the dielectric barrier discharge (DBD) plasma actuator forcing direction on stall margin improvement and aerodynamic performance of a low-speed axial compressor rotor. The effects of plasma actuator induced force at yaw angles of 0, +30, −30° relative to the rotational axis of the compressor were evaluated through the incorporation of body force spatial distribution into Navier-Stokes equation. The evaluations focused on compressor performance comprising rotor efficiency, total pressure rise coefficient, span-wise loss coefficient, and diffusion factor on one hand and the tip leakage flow structure on the other hand in each configuration. The results indicated that reduction of mass flow rate could be associated with rotor tip spillage and trailing edge backflow, leading to the occurrence of the stall phenomena and flow blockage in the rotor tip region. However, using plasma actuators led to the energized tip region flow structure and improved aerodynamic performance by reducing the size of the tip leakage vortex and flow blockage. Specifically, among proposed configurations, the forcing direction at a yaw angle of −30° improved the compressor stall margin by about 8%. This is mainly due to the higher plasma jet velocity in the relative frame of reference versus to other configurations resulting in higher injected momentum to the tip leakage flow. The results propose counter-flow induced forcing direction as a favorable configuration for stall margin improvement.