4pAA8. Higher-order modal reflection and transmission in acoustic waveguide junctions.

Session: Thursday Afternoon, May 16

Time: 4:30

Author: Ralph T. Muehleisen
Location: Appl. Res. Lab., Penn State Univ., P.O. Box 30, State College, PA 16804


Analytic expressions for the transmission and reflection coefficients of higher-order modes in acoustic waveguides are developed and explored.When written in matrix form the equations take on the standard form of an impedance discontinutity. Numerical results for a right angle bend and a T junction show that there is significant coupling between modes, especially to the plane-wave mode. The results indicate that modal coupling cannot be ignored in the design of active and passive attenuators that need to work at higher frequencies.

from ASA 131st Meeting, Indianapolis, May 1996