Field reconstruction by acoustic holography technique based on BEM

This paper presents a technique of surface field reconstruction for non-separable geometry based on the boundary element method and the singular value decomposition. The sound sources are axisymmetric bodies with arbitrary boundary conditions. The hologram data are got from a cylindrical surface that encircles the source. By the use of axisymmetric property of the body, the two-dimensional integral formulation is reduced to one-dimensional integral along the generator of the body, as the pressure and normal velocity on the surface is expanded in a Fourier series with regard to the angle of revolution. The Fourier coefficients can be evaluated by using elliptic integrals and Gaussian quadrature formula. An improved SVD method is given to get the generalized inverse of the complex matrix. The acoustical quantity on the source surface can be calculated by inverse transformation. The method is tested on numerically generated data.