DETERMINATION OF THE MUTUAL RADIATION RESISTANCES OF A RECTANGULAR PLATE AND THEIR IMPACT ON THE RADIATED SOUND POWER

The mutual-radiation resistances resulting from cross-modal coupling have been mostly excluded from sound power calculations on the belief or premise that either for some reasons they have an insignificant impact on the power radiation or consideration of them can be an enormous computational burden. In this paper, the characteristics of the mutual-radiation resistances are investigated of a simply supported rectangular plate. It is shown that, once the self-radiation resistances (or the so-called modal-radiation efficiencies) have been calculated, the mutual-radiation resistances can be readily obtained at virtually no cost. Of equal importance, because no approximation is made, the present formulation is fully accurate in the entire frequency range. An asymptotic expression is also derived for large modal wavenumbers. Numerical results are presented to illustrate the spectral characteristics of the mutual-radiation resistances and the corresponding impact on the radiated sound power.