ASA 127th Meeting M.I.T. 1994 June 6-10

5aSA7. On the interaction of sound from a jet with a nearby structure.

Jennifer L. McGreevy

NASA Langley Res. Ctr., Structural Acoust. Branch, MS 463, Hampton, VA 23681-0001

Alvin Bayliss

Northwestern Univ., Evanston, IL 60208

Lucio Maestrello

NASA Langley Res. Ctr., Hampton, VA 23681-0001

The excitation of a flexible beam by acoustic disturbances generated by a spreading subsonic jet and the resulting interaction and acoustic radiation is investigated numerically. The formulation consists of solving the nonlinear Euler equations coupled to a nonlinear equation governing the vibration of the panel due to acoustic loading. The incident sound waves result from both disturbances due to the initial source as well as disturbances generated by instability waves in the jet. Under appropriate conditions, instability waves can also be generated upstream of the nozzle exit and may contribute additional sound. Results are obtained for the panel response as well as the transmitted and reflected acoustic field from the flexible panel.