Modelling of vehicle interior noise at reduced scale

The present paper describes some recent results on the development of simplified reduced-scale models that can be used for experimental studies of vehicle interior noise. In many important cases such simplified structural models can be described analytically, thus providing a developer with the effective engineering tools for prediction and mitigation of vehicle interior noise, especially on a design stage. The general approach is illustrated by a 1:4-scale simplified model of a car developed at Loughborough University – 'QUASICAR' (QUArter –Scale Interior Cavity Acoustic Rig). The model consists of a curved steel plate that is simply supported by two rigid side walls made of massive wooden panels. The effect of road irregularities exciting vehicle structural vibrations is imitated by electromagnetic shakers applied to the bottom of the steel plate. Measurements of structural vibrations and of the acoustic pressure generated inside the model are compared with the results of theoretical predictions.