Acoustic properties of the porous material in a car cabin model
This paper predicts the acoustic properties of the porous material in a car cabin model by using an appropriate experimental method, and it verifies the estimated acoustic properties by conducting the FEM (Finite Element Method) analysis. A simplified vibro acoustic system imitating a car cabin is set up. The car cabin is made of six rigid walls, and a flexible panel is mounted on the front firewall position. The porous material is applied to the inner surface of the panel and modifies the coupling between the panel and the cabin air cavity. The panel is mechanically excited by using an electromagnetic shaker, which is imitating the structure borne noise. The radiated noise is recorded by using pressure microphones at the different locations inside the car cabin. Based on the model proposed, the effect of the porous material on the acoustic properties is investigated by using the Sound Pressure Level (SPL) at the microphone locations. Finally, the experimentally acquired acoustic properties of the porous material are compared with the numerical analysis of FEM. The simulation results show that the proposed model agrees well with the experiment data. The noise propagating inside the car cabin is predicted to be of similar level in both the experimental method and in the numerical analysis.