Abstract
Excessive noise radiated by pipes consisting of air or steam are often lagged using porous materials of high flow resistivity and impervious sheets usually made from metals and plastics. This paper looks at the prediction of insertion loss associated with the lagging of cylindrical pipes. A method is described and a program to efficiently calculate the predicted insertion loss as a function of frequency is developed. Predicted values of the insertion loss are compared with measured values found in past literature. Accompanying this is a comparison of the predicted values compared with current recognised theoretical results. Finally an in-depth parametric study is presented.