Abstract: A method for solving vibro-acoustic coupling field in complex enclosures based on Daubechies wavelet scaling functions under Galerkin framework is developed considering the compactly supported orthogonal property of wavelets and differentiable natures of Daubechies wavelets and their scaling functions. Due to the derivatives and integrals of Daubechies wavelet being highly oscillatory, it is unstable to compute the connection coefficients by the numerical evaluation. Dedicated algorithms are devised for the exact evaluation of connection coefficients occurred in solving vibro-acoustic system based on the two-scale equation. Then an example of a car-like cavity is given and the wavelet-Galerkin method is applied to the cavity to get the distribution of the pressure in it at a frequency between 20 Hz and 250 Hz. An experiment is carried out to show the validity of the new method. The compared result demonstrates that the new method is efficient for predicting the natural frequencies and the pressure distribution of the coupling field.

Key words: Complex enclosure, Connection coefficient, Vibro-acoustic coupling field, Wavelet-Galerkin method