Calculating total acoustic power output using modal radiation efficiencies

Over the last 20 years a great deal of work has been devoted to obtaining expressions describing the radiation efficiencies of structural mode shape functions, in an effort to qualify the radiation characteristics of the structure. These modal radiation efficiencies cannot, however, be used directly in the calculation of total radiated acoustic power, as this latter quantity is not equal to the sum of the acoustic power radiated by each mode vibrating on its own. This paper addressed the problem of using modal radiation efficiencies to calculate the total acoustic power output of a simply supported rectangular panel. It is shown that there is an extremely simple way to use modal radiation efficiencies to calculate the total acoustic power output of the panel, the accuracy of which is limited only by the same low-frequency constraints placed upon the accuracy of the modal radiation efficiencies themselves.