Computational Simulations of Fluidic Actuation on Rotor Blades and Their Experimental Validation

Abstract

Active flow control (AFC) is conventionally used to reduce flow separation at high angles of attack. A novel alternative form of AFC for controlling rotor blade loads in attached flow is examined. The AFC system employs pulsed fluidic jets near the trailing edge of a VR-12 airfoil on the pressure side and suction side. Each jet has two operating modes: tangential blowing and normal blowing. Unsteady Reynolds-averaged Navier–Stokes simulations are performed to characterize the unsteady aerodynamic phenomena induced by actuation at low and moderate angles of attack. The simulation approach is validated using data from recent low-speed () wind-tunnel experiments. The normal blowing modes produce nearly symmetric changes in the lift and moment that are proportional to the relative jet strength. The tangential blowing modes have a minor effect on lift and moment but have a beneficial effect on drag. High-speed simulations, up to , are also performed to determine the effect of freestream Mach number on actuator performance. Finally, simulations representing rotor blade dynamics during vibrations are carried out to illustrate the effect of unsteadiness associated with blade motion. This is the first instance showing that AFC is a viable approach for potentially controlling rotor vibrations in attached flow.