Road noise radiation inside and outside a vehicle

Road noise emission at the rear wheel of a car can either go through the vehicle or on the lateral side of the car. This paper deals with computation performed in order to determine the partial power balance around the wheel and around the car cabin. These two acoustic power balances will help us to identify the main acoustic paths and to find how to reduce acoustic pressure level for pedestrian and for car passenger with increasing absorption efficiency on external surface. First section deals with partial power balance in the wheel envelop, radiating outside of the car. Results on this section are checked, thanks to previous experiments and computations. In the second section, we focus on acoustic power balances of rear car body panels. Numerical results presented in this section will be compared to available acoustic pressure measurements, in order to sort the main acoustic paths and to identify weakness of the transmitted surfaces.