Date of Award
Program or Major
Doctor of Philosophy
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.
Mohd. Ghazali, Normah, "Numerical simulation of acoustic waves in a rectangular chamber" (2001). Doctoral Dissertations. 53.