Diffraction of an acoustic wave at a moving plate

The diffraction of an acoustic wave at a plate moving in an ideal gas is treated as an initial value problem with movable boundary for a two-dimensional wave equation. The solution is obtained in closed form in quadratures for the case when the plate is moving at subsonic speeds according to an arbitrarily given law and the acoustic wave is incident on the plate at an arbitrary angle. The solution is presented in the form of recurrent formulas and takes into account the effect of any number of diffraction waves arising consecutively at the plate boundaries.