Numerical Acoustic Radiation Models
A phenomenon difficult to identify and quantify is the complex relation betweeen structural vibrations and the sound caused by those vibrations (structure borne,sound). This relation is important since a large percentage of the noise pollution is of structure borne nature. Whenever a mechanical structure producing vibrations is conceived, measures should be taken to reduce the sound inherent to those vibrations. To do this efficiently the sound radiation mechanism must be first identified and quantified in appropriate models. The theoretical base for such a model is known since more than a century, and is given by the solution of the 3d wave equation, with the surface velocity of the vibrating structure as boundary condition. Several theoretical studies have been devoted to this subject in the past and have resulted in analytical formulas which are only valid for a limited number of relative simple source geometries such as axisymmetric structures (spheres, cylinders) or flat plates. Analytical solutions for the general radiation problem do not exist, numerical solutions are conceivable but rather complex due to numerical instability problems, and hence require considerable computer power.
KeywordsAcoustic Radiation Acoustic Power Radiation Model Radiation Efficiency Sound Power
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