“Sporty” Feeling Control of Automobile Engine Sound with Sound Absorbers

Sound Radiation Analysis of Automobile Engine Covers

A methodology to study the sound radiation of engine valve covers is presented. The analysis process uses a nonlinear static simulation followed by a steady state dynamics simulation to determine the sound pressure field due to the vibration of the engine cover. The effects of assembly loads are included. The methodology is demonstrated with two representative engine valve covers using acoustic...

Vibroacoustics of thin micro-perforated sound absorbers

Effect of porosity on the characteristics of underwater acoustic sound absorbers using theoretical models‎

Porous materials have good acoustic damping characteristics over a wide frequency range. As for sound waves, many small-scale pores in the coating materials can convert underwater-coating to rough surfaces. The main property of porous absorbents is their resistance against incident sound wave that leads to damping effect. From a physical point of view, damping occurs due to friction between flu...

Investigation on acoustic behavior of acoustic porous absorbers to ‎absorb sound energy and transmission loss index

In this study, the acoustic properties of porous absorbents with different porosity levels have been evaluated using different mathematical models. These models use one or more parameters of materials for calculating acoustic characteristics. In all of these models, materials are considered as equivalent fluid and reactionary characteristics have not been taken into account.

Sound attenuation using duct silencers with micro-perforated panel absorbers

Micro-perforated panel (MPP) can be used as non-fibrous acoustic absorber which can provide broadband sound absorption performance. In this study, a sub-structuring methodology based on the Patch Transfer Function (PTF) approach to deal with duct silencers with MPP absorbers and internal partitions is proposed, and the sound attenuation performance of such silencers is investigated. Reactive si...