Vibro-acoustic design of covers for belt drives

In the development of modern engines, one of the most critical aspects is represented by the reduction of noise emission for the optimization of interior acoustics in vehicles and the minimization of pass-by noise. The covers, which are always present in engines for different purposes (valve and distribution covers, oil pan...), have become a relevant noise radiation cause, justifying any effort made to reduce their contribution to the overall noise produced. This paper describes a systematic approach to the problem. An optimization process is put into place, which would be able to provide effective design modifications. Such a process is based on an accurate vibro-acoustic modeling by means of simulation codes as well as on an experimental stage, necessary to develop and validate the numerical models. All the steps of this optimization process have been applied to the practical case of a cover for belt drives and are presented in this paper.