A Study of the Packaging of a Small Engine : 2nd Report Theoretical investigation of the Sound Insulation Effect of Package

Abstract

It is an important but difficult problem to manufacture a special engine which is inherently quiet. So, the question of the day is to reduce the radiated noise by enclosing an engine in a suitably designed package. In this paper, the sound attenuation effect of the package is analyzed theoretically for an enclosed engine, and theoretical equations are obtained for two cases where the dimension of package is very large compared with the wavelength of sound wave and where the dimension is very small compared with the wavelength. Moreover, theoretical analysis is performed regarding the sound transmission loss of various types of package walls and some interesting results are obtained.