RADICATION POWER OUTPUT FOR 2-DIMENSIONAL ARRAY OF TRANSDUCERS IN WATER USING FAR-FIELD AND NEAR-FIELD TECHNIQUES

The radiation efficiency for a two-dimensional array of transducers is determined from the acoustic power radiated to the farfield, i.e., th e farfield technique. The radiation efficiency curves can be classifie d into three types: (a) quadrupole type (even-even mode), (b) dipole t ype (even-odd mode) and (c) monopole type (odd-odd mode) as suggested by Maidanik(1)) for a vibrating panel. To attain a global reduction in the farfield intensity, the power output of individual transducers mu st be considered when designing or evaluating an active sound power co ntrol. The power output radiated from individual tranducers is then de termined using the nearfield technique based on the self- and mutual r adiation impedances. The agreement between theoretical and experimenta l results is satisfactory.