EXPERIMENTAL ANALYSIS OF INNOVATIVE ACOUSTIC MATERIALS FOR ENGINE NOISE CONTROL IN VEHICLES

Due to the continuous evolution of vehicle noise regulations, the automotive industry is increasingly looking for more efficient engine bay design solutions to control noise coming from the engine. To this aim, proper acoustic treatments and covers made of multilayered trimmed panels need to be se-lected. Hence, present study reports the results of an experimental investigation aiming to characterize the acoustic properties of innovative absorbing materials to be used in a new identified engine encap-sulation solution. Both sound absorption and sound insulation properties of several selected materials were measured by using an impedance tube. A sound intensity method, as specified by ISO 15186 standard, was finally utilized to assess the sound insulation performance of prototypes of the acous-tically-treated component. In the paper, the acoustic performances of the tested materials are com-pared with reference to standard polyurethane foam based materials, in order to identify more efficient engine encapsulation solutions both in terms of acoustic performance and ease of industrialization.