Jp. Chambers et Yh. Berthelot, TIME-DOMAIN EXPERIMENTS AN THE DIFFRACTION OF SOUND BY A STEP DISCONTINUITY, The Journal of the Acoustical Society of America, 96(3), 1994, pp. 1887-1892
Experiments have been conducted to study the propagation of sound over
a rigid surface with a step discontinuity. The Biot-Tolstoy-Medwin (B
TM) model of a rigid wedge [J. Acoust. Soc. Am. 69, 1060-1064 (1981)]
is used to predict the acoustic field directly in the time domain. Exp
eriments carried out with a transient acoustic spark source confirm th
at: (1) in the region where there are no direct reflected waves, diffr
acted waves combine with diffracted/reflected waves to produce a smoot
h transition; (2) the acoustic field around the step discontinuity can
be highly directional due to the interference of the direct, the refl
ected, the diffracted, and the diffracted/reflected waves; and (3) the
acoustic field is essentially unchanged if the step discontinuity is
replaced with a smooth step whose radius of curvature is less than the
characteristic wavelength of the incident sound.