Three-Dimensional Sound Wave Propagation Reproduction by CE-FDTD Simulation Applying Actual Radiation Characteristics

The compact explicit finite difference time domain (CE-FDTD) method has been proposed as a non-steady-state analysis method and used for sound field simulation. For sound field simulation, it is necessary to apply the radiation characteristics to reproduce actual sound wave propagation. Radiation characteristics can be applied by setting sound pressure to dense grid arrangement in the CE-FDTD method. However, conventional techniques use a sparse array of microphones and are considered insufficient. Furthermore, the technique of applying captured acoustic signals for dense grid arrangement in the CE-FDTD method has not been considered. In this paper, we propose a hardware and software system that captures the radiation characteristics for a dense grid arrangement and applies them in the CE-FDTD method while controlling the sound wave propagation with non-propagation region. As a result of the proposed method, the average differences of sound pressure, propagation time, nd center frequency from the measured values are 1.8 dB, 0.04 ms, and 200 Hz, respectively, which is more accurate than the conventional techniques. It is shown that this system is useful for improving the accuracy of sound wave propagation reproduction with actual radiation characteristics.