Dept. of Mech. Eng. and Appl. Mech., 120 W. E. Lay Automotive Lab., Univ. of Michigan, Ann Arbor, MI 48109-2121
J. M. Novak
Ford Motor Company, Dearborn, MI 48121
The present study investigates the performance of fundamental reactive silencers such as expansion chambers and Helmholtz resonators in the presence of both high-amplitude pressure waves and oscillating fluid flow. The silencers are installed in the induction system of a Ford 3.0-Liter V6 Vulcan engine in a dynamometer test facility. The experiments with the firing engine have been conducted with speeds ranging from 1000 to 5500 rpm. Measurements including the mean flow rate, the temperatures, and the absolute dynamic pressures of the induction air before and after the silencer with fast-response, piezoresistive transducers facilitate the calculation of acoustic and flow performance of these elements. A nonlinear computational fluid dynamics method is then employed in the time domain for the prediction of noise reduction and insertion loss characteristics of these silencers. The study is concluded with comparisons of these predictions to the experimental results from the engine dynamometer facility.