Flow Noise Predictions for Automotive Air Rush Noise

Abstract

Noise from automotive air handling systems is an important issue for driver comfort. This study was undertaken to quantify the noise from the air handling system and to develop a predictive model for the noise level and spectrum at the drivers right ear location. Tests were conducted on six vehicles to develop the predictive model and then four more vehicles were tested and used to verify the prediction model. All vehicles tested were production level designs ranging from small economy cars to large luxury trucks. The study shows that the noise generated by the air handling system can be modeled with the parameters of static pressure across the blower (ΔP) and system air flow rate (Q). When the measured noise levels were compared to the predicted noise levels, there was a mean error of −0.03 dBA with a standard deviation of 1.31 dBA for all vehicles and for various modes of operation. This model can be used in the early stages of design using CFD/CAE analysis, or in evaluating the effects of design changes on the sound pressure level and spectrum.