FORWARD-FLIGHT ANALYSIS OF SLATTED ROTORS USING NAVIER-STOKES METHODS

The objective of this study is to evaluate the aerodynamic effects of leading-edge slats on rotor. blades under high-speed forward-flight co nditions. A partial-span leading-edge slat is proposed for the inboard portion of the existing UR-60A rotor. Some two-dimensional slat studi es are done to optimize the slat orientation at low subsonic Mach numb ers. A multizone unsteady three-dimensional compressible Navier-Stokes solver is developed to compute such rotor/slat configurations. The ro tor wake is captured from first principles. Some forward-night results are presented for the UH-60A slatted rotor and compared with the base line rotor case. The surface pressures and the force coefficients indi cate that the slat is beneficial in reducing the retreating side dynam ic stall. It was found that the slat reduces the torque and pitching m oments on the retreating side compared to the baseline configuration.