A hybrid CFD/integral approach is used to predict the noise spectrum of a real automotive fan cooling system. The tonal and broadband noise spectral components, mainly due to the coherent and random part, respectively, of the unsteady pressure fluctuations induced by the rotor-wake/stator-vane interaction, are computed by applying a Ffowcs-Williams & Hawkings acoustic analogy to the wall pressure field provided by a transient Reynolds-averaged Navier-Stokes simulation, with superimposed random fluctuations computed through a stochastic method. The RANS turbulent quantities are used to generate solenoidal stochastic velocity fluctuations that contribute to define the right-hand side of a Poisson equation for the pressure perturbation. The Poisson equation is cast into a boundary integral equation and solved by means of a boundary element method. The noise spectra at different angles with respect to the fan axis are computed and compared with available experimental data.
One, no one and one hundred thousand methods for low-speed fan noise prediction
Damiano CasalinoRelated information
1 CIRA, Italian Aerospace Research Center, Capua, 81043, Italy
, Stephane MoreauRelated information2 VALEO Motors and Actuators, La Verrière, 78321, France
, Michel RogerRelated information3 Ecole Centrale de Lyon, Ecully, 69134, France
Published Online: April 12, 2011
Abstract