The simulation of acoustic radiation from a moving line source with variable speed

The purpose of this work is to simulate and investigate the sound field generated by a moving line source with finite length and variable speed. Expect for the variation of the acoustic pressure at the specific field point, the distribution of the surface pressure along the surface of the line source was also considered. For achieving this purpose, a numerical method which combines the Time Domain Boundary Element Method (TDBEM) and moving sound source theory was developed in the present work. After comparing the results with the constant and the variable speed case, it showed that the effect of the variable speed not only influenced the variation rate of the frequency modulation, i.e., Doppler effect, but also the time about the maximum acoustic pressure being observed. In addition, the simulation results also presented that the difference as to the amplitude variation of the acoustic pressure still existed between the moving case and the stationary case even if the length of the line source is very long.