Prediction of RACER's Lateral Rotor Noise Using the CONCERTO Chain

International audience; This paper is aimed to present a computational chain developed in the framework of the CleanSky 2 European CONCERTO project. This computational chain is devoted to the prediction of the noise emitted by the lateral rotors of the Airbus Helicopters' RACER demonstrator using both fast prediction and high fidelity approaches. One of the main challenges addressed in this paper is the capacity to predict rapidly the aerodynamic and acoustic interaction effects due to the vicinity of the wings and the fuselage. From an aerodynamic point of view, it is proven by comparison with high-fidelity results that it can be achieved thanks to a free-wake code using velocity perturbation fields to properly take into account the wings wake viscosity effect and to solve issues linked to the rotational speed difference between the main rotor and the propellers. Comparisons with a Boundary Element Method code show also that a Kirchhoff approximation appears to be a good option to rapidly assess, at least in terms of tendencies, the impact of near solid surfaces on the noise radiation.