Use of the Raytracing Based Solver BEAM for the Evaluation of Transfer Functions within the Time Domain

As part of the research project "Computational Acoustics", the raytracing-based solver BEAM has been developed in recent years to determine the backscattered sound pressure in the far field. This solver is able to calculate the scattering of complex structures composed of fluids and / or elastic materials (in the form of thin layers). Due to its high computing speed, it is therefore well suited for sweeps over a given frequency range. The article introduces an extension of the postprocessor, which converts a transfer function into a temporal or spatial impulse response by means of the FFT and displays it graphically, also in 3D. This representation allows the user a visual assignment of the signals to the external and possibly internal structure of the observed objects. Using a complex structure with different material combinations, first results for the backscattered sound field are presented, analyzed and, if available, compared with results of BEM and FEM calculations.