Practical Implementation of the 3D Tetrahedral TLM Method and Visualization of Room Acoustics
This paper concerns the implementation of a 3D transmission line matrix (TLM) algorithm based on a tetrahedral mesh structure and visualization of room acoustics simulation. Although a well known method, TLM algorithms implemented in 3D are less commonly found in the literature. We have implemented the TLM method using a tetrahedral mesh of pressure nodes with transmission lines lying superimposed on nearest neighbour bonds of a tetrahedral atomic lattice. Results of simulations are compared with those of a standard 3D cartesian mesh and a 2D mesh implementation of TLM. An important feature is a useful graphics interface designed for user-friendly control of room acoustics simulation and visualization in arbitrary shaped rooms containing objects of arbitrary size and number. The paper includes brief discussions of results of using different techniques for modeling totally absorptive or partially absorptive boundaries.