Active Control of Unsteady Blade Loads for Installed CROR Propulsion Systems

Contra Rotating Open Rotor (CROR) propulsion systems show promise as a highly economic and environmentally friendly powerplant for future transport aircraft. Installation effects, i.e. the mutual interactions between airframe components and the rotors, have a pronounced impact on the aerodynamic and aeroacoustic performance for this type of engine. In the present study, a coupled aerodynamic and aeroacoustic analysis using the DLR numerical methods TAU and APSIM is performed to assess the potential of pylon blowing to achieve a reduction of unsteady blade and rotor loadings and corresponding noise emissions caused by the installation of the powerplant on the aircraft.