Aeroelastic Control on Compressor Blades With Virtual Control Surfaces: A Numerical Assessment

Plasma actuators are numerically implemented as virtual control surfaces to reduce turbomachinery blades vibration and enlarge flutter-free ranges. Actuators are located at the trailing edge of the blades, both on pressure and suction side, and are triggered either independently or alternately. Upstream blowing — i.e. plasma operating in a way that the induced flow is against the freestream — has been assessed by the authors in a previous work, and is now compared with downstream blowing — i.e. plasma-induced flow in the direction of the freestream. Steady state and traveling-wave mode calculations are performed. Transient results indicate that both upstream and downstream actuation increase remarkably the stability of the cascade. This improvement in the aeroelastic response is observed for the entire interblade phase angle range. Furthermore, the effects of locally actuating the flow on lift, drag and moment coefficients are typified. A wide range of angles of attack and blowing forces is simulated. The obtained results demonstrate that also downstream plasma actuation can be a powerful tool to deal with aeroelastic instabilities on turbomachinery, and make worthwhile to assess further in-depth the capabilities of the two actuation approaches.