Abstract
This paper presents the application of the CAE to the reduction of the noise radiated from the blower of a fuel cell electric vehicle. The blower is operated up to 25,000 rpm and then its noise level is very high so that the noise is heard inside of a vehicle. The interior sound quality of the vehicle is not very good and need to be improved. The major reasons of the noise are two. One is the noise caused by the structure-borne, the other one is due to the air-borne. In this paper, the structure of the blower is optimized to reduce the structure-borne noise by using the CAE technology. The FE (finite element) model of blower is composed by using CATIA and this model is confirmed by the EMA(experimental modal analysis) based on signal processing. The noise reduction by the only structure modification is not enough to the reasonable level. Therefore, the damping of the structure is also controlled by the damping material. The loss factor of the damping material is also estimated to reduce noise level sufficiently based on the CAE. The damping material enclosed the surface of the blower. These two treatments for noise reduction are efficient to achieve the target noise revel.
Key Words : Modal Analysis, Finite Element Method, Boundary Element Method, Radiating Noise, Blower