THE RADIATION OF ACOUSTIC-WAVES BY A PISTON RADIATOR IN A RIGID SCREEN PARTIALLY COVERING A WAVE-GUIDE CROSS-SECTION

The steady excitation by a piston radiator of normal modes in a plane acoustic waveguide with absolutely rigid side walls is investigated. T he radiator, which has mass, is elastically coupled to a rigid screen and is placed at its centre, and the screen is situated at the centre of an absolutely soft end-wall of a semi-infinite waveguide. The Wiene r-Hopf-Fock method is used to construct a solution of the problem for the case when the screen half covers the end-wall of the waveguide, wh ile the dimensions of the radiator are arbitrary. The amplitudes of th e normal modes and the acoustic fields excited by the radiator in the waveguide are investigated analytically and numerically. (C) 1997 Else vier Science Ltd. All rights reserved.