Theoretical and Experimental Study of an Acoustic Monopole Source

As it is well known, the acoustic monopole source plays a fundamental role in the fields of theoretical and experimental acoustics. In this work, a sound source that well approximates the dynamic response of a theoretical monopole is designed and the parameters affecting its operational behavior are highlighted and optimized in terms of sound power and range of reproducible frequencies. We develop a hybrid lumped-parameter-finite-element model for describing the source operation. The model is first experimentally tested to validate its predictive effectiveness. Then, we perform a non-dimensional parametric optimization of the source directionality, obtaining relationships with which general design guidelines are identified, to minimize the far field directionality and, thus, achieve a quite omnidirectional behavior.