Sound Radiation Modes of MDOF Waveguide Suppressor in Outer Fluid

Abstract

For a multiple degree-of-freedom (MDOF) waveguide suppressor attached to a large baffleplate, we achieved the analysis solution to this problem by replacing a MDOF waveguide suppressor as an equivalent Timoshenko beam. Based on the theory of acoustic radiation mode, we discussed the properties of acoustic energy radiated from MDOF waveguide suppressor and acoustic energy transfer in outer fluid, which indicate the patterns of acoustic energy radiation and transfer in fluid. The surface sound intensity and fluid sound intensity may be classified into two parts1 one part can propagate towards the far field, while the other part may exchange between suppressor and fluid within the near field, which means only when we curb the acoustic energy radiation patterns of waveguide suppressor propagating to the far field effectively, can we depress the sound radiation level in outer fluid.