THE SOURCE SIMULATION TECHNIQUE FOR ACOUSTIC RADIATION PROBLEMS

The basic idea of the source simulation technique is to replace the ra diating body by a system of simple sources located within the envelope of the radiator. The extent to which the simulated held reproduces th e original field depends on the degree of correspondence between the s imulated and the given boundary conditions. There are a number of diff erent variants of the source simulation technique which can be classif ied according to the kind, number and locations of the sources or to t he minimisation process which is applied. A mathematically rigorous ba sis is given for particular methods of the source simulation technique by showing the convergence of the simulated to the true solution by i ncreasing the number of sources for the Neumann, the Dirichlet and the general impedance problem. Various strategies for minimising the boun dary error are investigated and the corresponding error functionals ar e given. For algorithmic implementation important aspects, such as the occurrence of critical frequencies and instabilities due to ill-condi tioning of the problem or due to symmetries are considered with respec t to different variants of the source simulation technique. Symmetry p roblems are investigated in the context of a vibrating propeller.