Aerodynamic and Aeroacoustic Analysis of Contra-Rotating Open Rotor Propulsion Systems at Low-Speed Flight Conditions

Abstract

Contra Rotating Open Rotor (CROR) propulsion systems have come back into focus as a possible economic and environmentally friendly powerplant for future transport aircraft. Having been widely applied to the simulations of single rotation propellers, the DLR CFD code TAU and the aeroacoustic analysis tool APSIM have been employed for the analysis of the complex aerodynamics and aeroacoustics of this type of aircraft propulsion. In order to demonstrate the codes applicability to these types of simulations, a generic 8x8 pusher CROR powerplant was designed and uRANS computations at typical sea-level take-off conditions of M = 0:2 were performed for two angles of attack. The results allow for a detailed analysis of the aerodynamic interactions between the two rotors as well as the noise generation mechanisms.