OPTIMAL-DESIGN OF ACOUSTICAL FOAM TREATMENTS

A finite element model for elastic porous materials is presented that allows for interfaces with adjacent acoustical media that are arbitrar ily oriented with respect to the global coordinate system. The foam fi nite element is based on a complete elastic porous material theory tha t can account for all the three wave types known to be significant in foams. Example problems are used to illustrate the application of foam finite elements to the optimal design of a foam wedge terminating a w aveguide. The wedge angle is used as a design parameter (while the wed ge volume is held constant) and the performance measure is the frequen cy-averaged absorption coefficient.