Contribution
Dynamic Spatial Discretization of Sound Field Calculation of Arbitrary Shaped Sources via Generalized Ray Theory
* Presenting author
Abstract:
The generalized ray theory calculates elastic waves emitted by concentrated normal point forces into parallel, multi-layered media by utilizing integral transforms. For extended, non-axisymmetric sources, the spatial convolution required for the impulse response is commonly discretized to a sum over the field of point sources. This static discretization becomes increasingly computationally intensive as the number of point sources increases, since an integral must be numerically calculated for each pair of point source and observation point. This contribution presents a new dynamic discretization approach by representing an arbitrary shaped source as a function that expresses the length of the intersecting arc of a circle around a given observation point with the source region. This function is used to determine an optimal distribution of point sources for the observation point in each time step resulting in only one integration for all observation points that are the according distance away from the source. Comparing the static and dynamic approach regarding the spectral distribution of discretization noise versus the number of nodes highlights the gains in efficiency when using the dynamic approach. This makes it possible to calculate impulse responses of finitely extended sources to optimise transducers, estimate achievable accuracies and develop evaluation methods.