A HIGHER-ORDER FINITE-DIFFERENCE TIME-DOMAIN METHOD FOR SOUND PROPAGATION

A higher-order Finite-Difference Time-Domain method for acoustics is presented, namely, a second-order-in-time, fourth-order-in-space method: FDTD (2, 4). The influence of the stability condition on FDTD (2, 4) is investigated, and we compare this method with FDTD (2, 2) in one-dimensional coordinate system. From the results of numerical dispersion analyses and sound wave propagation, we know that the higher-order method computes faster and more stable than the second-order method. This signifies that a larger space step size can be chosen by the higher-order method for the same excitation, which will reduce the computer memory on a coarse grid. This higher-order method is also simulated in the impedance boundary which is close to an actual wall. The results prove that higher-order method has a high efficiency and can be used in more complex room boundaries.