Abstract
Boundary element methods (BEM) in conjunction with optimization algorithms are employed for active noise control of sound fields in three-dimensional enclosures. Total time-averaged acoustic potential energy is chosen as the cost function for the optimization procedure. The BEM is used to model the monochromatic sound field generated by noise sources in the enclosure. The constrained steepest descent method proves to be effective when both positions and amplitudes of the secondary sources are to be optimized, while the direct matrix inversion, the steepest descent method, and the conjugate gradient method prove to be useful when only the amplitudes of secondary sources are to be optimized. The developed BEM-based optimization techniques are applied to control the noise in a rectangular enclosure and a vehicle cabin.