Numerical study of acoustic installation effects through a chimera CAA method

This paper deals with the numerical study of installation effects, a subject which is relevant of the more general purpose of the aircrafts noise prevision and reduction. As an example of installation effects, we study here the potential shielding effect that an empennage airfoil could offer to the reduction of the aft fan noise produced by a coaxial engine. Because the numerical simulations constitute an as powerful as cheap tool of investigation, we use for it a solver developed at ONERA, the sAbrinA CFD/CAA platform. In particular, we take benefits from an innovative overlapping method recently implemented in it - a method which allows handling more easily the solid obstacles to be considered. As an illustration of both the methodology and the tool, a full-3D aft fan noise propagation is then computed over an installed (over an airfoil) engine.