Integrated “CFD-Acoustic” Computational Approach to the Simulation of a Contra Rotating Open Rotor at Angle of Attack
Paper from 19th AIAA/CEAS Aeroacoustics Conference – May 27th-29th, 2013, Berlin, Germany
An innovative integrated computational approach, that includes mesh generation, CFD analysis and acoustic propagation, is presented and applied to the simulation of the F7/A7 Contra Rotating Open Rotor (CROR) tested in the NASA Lewis 9- x 15-ft Anechoic Wind Tunnel.
The tonal noise source is predicted starting from the engine geometry and the CFD calculated flow properties. The simulation approach relies on the exploitation of an efficient CFD solver based on the Nonlinear-Harmonic (NLH) method. The far field noise radiation of the CROR configuration is evaluated by means of a free-field acoustic propagation tool based on the Ffowcs Williams-Hawkings (FW-H) formulation.
The final comparison between the numerical results and the available measurements highlights the capability of the methodology to accurately predict the unsteady flow field and the radiated sound field in flight conditions under an angle of attack. The applicability of the simulation chain to complex calculations at affordable computational cost is also demonstrated.