Research on the Directionality of Difference Frequency Sound Field Based on Circular Ultrasonic Array

In a closed environment of underground space, noise pollution is serious, and sound waves are required to have strong directionality, providing people with a relatively independent and quiet working space. In order to obtain a high directivity sound source, a method combining difference frequency sound field with the circular array of transducers is proposed. Firstly, the advantage and disadvantage of the sound field generated by difference frequency mode and the sound field radiated by direct vibration in conventional mode are demonstrated. Secondly, based on the principle of sound field radiation, the directivity function of differential frequency sound field of circular piston transducer with multi-circumference arrays is derived. Finally, the influence parameters of directivity of differential frequency sound field are determined by three-dimensional and two-dimensional directivity diagrams, which can provide reference for the design of acoustic directional transducer array. (paper)