Date of Award

Winter 2001

Project Type


Program or Major

Mechanical Engineering

Degree Name

Doctor of Philosophy

First Advisor

John McHugh


Numerical simulation of acoustic waves in a closed two-dimensional rectangular chamber is considered. The waves are generated by a membrane or piston boundary condition on one wall. The simulations are performed through many acoustic cycles. A stack of heat exchanger plates are sometimes included. The study is motivated by thermoacoustic refrigeration, a phenomena which uses soundwaves in a chamber to achieve a cooling effect.

The present study treats the flow numerically. The governing equations are the viscous compressible Navier-Stokes system, assuming a perfect gas. The numerical method employs a finite difference spatial discretization and semi-implicit time-marching procedure. Verification is accomplished by propagating linear acoustic waves.

The desired result of forcing is a standing wave. However, the results show a significantly more complex flow than the expected standing wave, including beating, crosswaves, and streaming. Vortex flow also appears near the wavemaker and in the area surrounding the plate.