Technical Paper
Sound Radiation of Engine Covers With Acoustic Infinite Element Method
2005-05-16
2005-01-2449
The engine valve cover is known to be major contributor to powertrain noise due to its large surface area and relatively small thickness. Thus, the acoustic analysis of the valve cover has become one of the key steps in the design process. The present paper describes an acoustic infinite element approach to model the sound radiation of the valve cover. The valve cover bolted to the engine block behaves like a vibrating membrane in an acoustic medium of infinite extent. Typically, the effect of the infinite medium is modeled using either the boundary element method (BEM), or by specifying an equivalent boundary impedance on the terminating surface of an acoustic finite element mesh (NRBC). In this paper, a third method is introduced, wherein the boundary impedances are replaced by acoustic infinite elements. The methodology is presented using two different models. In the first model, a cover with a geometrically simple shape is analyzed.