STUDY ON THE RADIATION ACOUSTIC FIELD OF RECTANGULAR RADIATORS IN FLEXURAL VIBRATION

In this paper, the radiation acoustic field of a rectangular radiator in flexural vibration is studied. The radiator is a rectangular thin plate in flexural vibration with simply supported boundary conditions. Based on the theory of Rayleigh integral, the acoustic pressure distribution of the radiator in its far field is obtained analytically and the near acoustic field of the radiator is also computed numerically. In the near field, the three-dimensional acoustic pressure distribution is obtained. In the far field, the two- and three-dimensional acoustic pressure distribution patterns are calculated. The dependence of the radiation acoustic pressure of the radiator on the vibrational order of the plate in flexural vibration is analyzed. It is demonstrated that the radiation acoustic pressure along the central axis of the radiator is always zero in the near and far acoustic fields, and the radiation near acoustic field and the far acoustic field are both directional. This is different from the acoustic field generated by an oscillating piston. On the other hand, when the vibrational order is increased, the acoustic pressure distribution of the radiator becomes complex.