Deriving time-domain models of structural-acoustic radiation into free space

A method suitable for calculating the acoustic pressure radiated by a baffled structure into free space in the time domain is presented. The method produces a s-domain transfer function between input force and acoustic pressure at any position in space. It is shown that the order of the Padé approximations inherent in the approach must be selected carefully to obtain good phase accuracy over the frequency range of interest. However, with careful selection of the appropriate parameters, the time-domain results closely match those obtained using the traditional frequency domain approach used in structural acoustics. An alternative modelling method which uses the Euler substitution to create a pressure/force transfer function is developed. The method is shown to require small computational powers and be accurate over a wide frequency range.