Modeling and Approximation of a Coupled 3-D Structural Acoustics Problem

Abstract

A growing area of research in the structural acoustics community concerns the problem of reducing structure-borne noise levels within an acoustic cavity. A specific example of this is motivated by the development of a new class of turboprob and turbofan engines which are very fuel efficient but also very noisy. The low frequency high amplitude acoustic fields produced by these engines cause vibrations in the fuselage which in turn generate unwanted interior noise. The passive control techniques which were initially considered were in general undesirable since the increased weight offset the advantages gained through the use of the new engines and lighter airframe materials. This then led to the study of active control techniques for this problem both in a frequency domain setting and from a time domain approach (PDE approach).

The research of H.T.B. was supported in part by the Air Force Office of Scientific Research under grant AFOSR-90-0091. This research was also supported by the National Aeronautics and Space Administration under NASA Contract Numbers NASl-18605 and NASl-19480 while H.T.B. was a visiting scientist and R.C.S. was in residence at the Institute for Computer Applications in Science and Engineering (ICASE), NASA Langley Research Center, Hampton, VA 23681.