FE fluid-structure interaction/experimental transmission loss factor comparison of an exhaust system

The purpose of this paper is to present a 3-D Finite Element Method able to simulate and predict exhaust transmission noise. The simulation takes into account fluid flow pulsation, aeroacoustic noise sources, flow-induced structural vibration as well as noise radiation in the far field of the exhaust system of a single-cylinder diesel engine. In order to study problems on fluid-structure interaction a 3-dimensional model has been created through a FEM simulation. The study includes the calculation of the transmission loss factor and the determination of which modes dominate the noise transmission. Simultaneously, an experimental measurement has been performed, in order to determine the transmission loss factor of the tested system. Finally, an experimental-numerical comparison has been performed. Experimental and numerical results have been compared and a good agreement has been found. The study opens the way to future developments in numerical simulation for external aeroacoustic problems through the use of Boundary Element Method in order to predict the exhaust-radiated noise.