Sound localization and quantification analysis of an automotive engine cooling module

Sound emissions of an automotive engine cooling system are studied using both single-microphone directivity measurements and a rotating beamforming technique. These provide reference acoustic data on such some new understanding the effect that radiator induces distribution sound sources. Indeed, results indicate that, above frequency limit allowed by Rayleigh criterion, it is possible to localize quantify noise sources even through heat-exchanger core. Moreover, for investigated operating points along fan performance curve, always distributed at tip blades and, in particular, leading edge. The present evidence, confirmed similar trends spectra with without heat exchanger, leads conclusion dominant mechanism turbulence-interaction noise. Nevertheless, this turbulence produced within gap between ring its casing rather than generated latter appears induce negligible transmission losses but, more significantly, found have minimal influence aerodynamic modification all analyzed conditions.