On the Numerical Prediction of Aerodynamic Noise via a Hybrid Approach

Abstract

The present paper constitutes a fraction of a more extensive study, which is dedicated to the numerical prediction of aerodynamic noise. Here, we first recall how a hybrid method can allow (or not...) simulating practical problems of aerodynamic noise, a special emphasis being put on the way its CFD (Computational Fluid Dynamics) and CAA (Computational AeroAcoustics) stages can be properly coupled. Focusing then on the so-called CFD/CAA ‘surfacic’ coupling approach, we explicit its advantages and drawbacks, highlighting in particular its unability to handle installed configurations. With the view of removing such a constraint, we finally propose an innovative ‘non reflective’ surfacic coupling technique, and validate it via two academic test cases based on both analytical and numerical (CFD) inputs. Finally, we briefly illustrate how far such technique can effectively help addressing installed aerodynamic noise problems, via coupled CFD/CAA calculations of the noise emitted by two cylinders in tandem, when installed within an experimental set-up.