ENERGY-EXCHANGE BETWEEN THE COUPLED MEDIA OF IMPULSIVELY EXCITED, FLUID-FILLED, ELASTIC CYLINDERS

The time domain response of an infinite fluid-filled pipe to an impuls ive line force of various azimuthal distributions is derived, based on the Kennard shell equations fully coupled to the interior acoustic fi eld and computing a double Fourier integration in the wavenumber and f requency domain. The transient radial velocity of the shell is used to compute the coupled pressure field in the fluid and investigate the i nstantaneous intensity vectors in the fluid field. These vectors, eval uated in the near field of the shell wall at several distances from th e input force for increasing time, give insight into the exchange of e nergy between the structure and the fluid as the various waves propaga te through the system. (C) 1995 Academic Press Limited