ASA 124th Meeting New Orleans 1992 October

5aSA3. Energy exchange between the coupled media of impulsively excited fluid-filled cylinders.

Chris R. Fuller

Bertrand J. Brevart

Vibration and Acoust. Labs., Dept. of Mech. Eng., Virginia Polytech. Inst. and State Univ., Blacksburg, VA 24061

The time domain response of an infinite fluid-filled pipe to an impulsive line force of various azimuthal distribution (circumferential modes 0 and 1) is first derived, based on the Donnell--Mushtari shell equations fully coupled to interior acoustic field and computing a double Fourier integration in the wave number and the frequency domain. The transient radial displacement of the shell is then used to compute the coupled pressure field in the fluid and investigate the instantaneous intensity vectors in the near field closely hugging the wall. These vectors, evaluated at several distances from the input force, give insight into the exchange of energy between the structure and the fluid as the various waves propagate through the system. [Work supported by ONR.]