Analytical and experimental study of sound transmission loss of acoustic enclosures

Abstract

Acoustic enclosures made of thin elastic structural panels are broadly employed in many industries and applications such as aerospace, submarines, tanks, and architectural structures and safeguarding human hearing in a noisy environment. The applications of the acoustic enclosure are significant because it reduces the sound transmission from noise sources such as operating machines or noisy engines. There is a need to evaluate the acoustic performance of enclosures due to the commercial demand for quieter systems. Sound transmission loss is identified as an effective physical measure for quantifying the capability of acoustical enclosures for attenuating noise. Noise control is of primary importance to design the acoustic enclosure. Hence, an accurate prediction model of transmission loss is usually required during the design and development phases of the acoustic enclosures. Numerous innovative methods have been developed by researchers for the analysis of sound transmission through acoustic enclosures and panels. However, the analytical methods based on the wave approach does not produce satisfactory results in the low-frequency region. Moreover, Numerical methods based on finite element and boundary element methods are not well suited to high-frequencies transmission loss calculation of complicated structures due to extensive computing resources and high computation time.