Mutual radiation between a bender transducer and virtual image

The equivalent model of the virtual image source of a single bender transducer is established.Using the pulsating sphere source model,the theoretical analysis of mutual radiation effect between a bender and its virtual image is done at first,then the mathematical expressions of mutual radiation impedance and resonant frequency of the system are derived.The idea of low frequency transducer design with virtual source interaction is proposed,two rigid circle baffles are set into the sound field near the radiation surface of a bender transducer,and the relationship between the resonant frequency and the main structural parameters of the low-frequency transducer is studied through theoretical analysis,finite-element simulation and prototype experiment.The results show that the resonant frequency of the transducer can be effectively reduced by the mutual radiation effect between the bender and the virtual image source.Compared with the resonant frequency of the bender itself,the resonant frequency can be reduced to less than 50% when the diameter of the reflector plate is equivalent to the diameter of the radiation surface of the bender,while it can be reduced to 37%when the diameter of the reflector plate is doubled.