Mode coupling in a sound channel with range-dependent parabolic velocity profile

Abstract

Pierce and Milder have developed a normal-mode theory with adiabatic separability for sound propagation in a channel whose environmental parameters depend not only on depth, but in a gradual fashion also on range. If range dependence is less gradual, the range equations become coupled and energy transfer between modes takes place. We have investigated this coupling phenomenon for a parabolic profile model with linear range dependence, using a method of approximate diagonalization for uncoupling the range equations, and have shown the energy transfer between modes to become significant for sufficiently large range variations of the profile.