Prediction of transmission loss of parallelepiped plenum chambers with liner

흡음재가 부착된 직방형 소음기의 전달 손실 예측

This paper deals with transmission loss of 3-dimensional rectangular plenum lined chamber. There are three kinds of rectangular plenum lined chamber: throughflow type, flow-reversal type, and end-in/side-out type. The combination of above three types of rectangular plenum lined chamber is used for the commercial HVAC system and automobile exhaust system. However, the ambiguity and complexity of sound absorbing material property and 3-dimensional property have impeded research. In this paper, the transmission loss of three kinds of rectangular plenum lined chamber is derived and calculated. The effect of increase of sound absorbing material is also considered. Analytical solution is calculated by using the locally-reacting property of sound absorbing material.