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.
","abstract_html":"<p>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.</p><p>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.</p><p>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.</p>","abstract_has_math":false,"creators":["Mohd. Ghazali, Normah"],"institution":null,"degree_name":"Doctor of Philosophy","degree_level":"Dissertation","degree_discipline":null,"degree_department":null,"school":null,"contributors":["John McHugh"],"advisors":[],"committee_chairs":[],"committee_members":[],"year":2001,"date_issued":"2001-01-01T08:00:00Z","date_published":"2001-01-01T08:00:00Z","updated_at":"2026-07-24T05:21:54Z","subjects":["Engineering","Mechanical"],"languages":[],"rights":[],"rights_urls":[],"identifier_entries":[]},"links":{"outbound_url":"https://scholars.unh.edu/dissertation/53","outbound_label":"Repository record","outbound_source":"dc:identifier"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor","label":"Contributor","values":["John McHugh"]},{"key":"dc:creator","label":"Author","values":["Mohd. Ghazali, Normah"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"thesis:degree_level","label":"Degree Level","values":["Dissertation"]},{"key":"thesis:degree_name","label":"Degree Name","values":["Doctor of Philosophy"]}]},{"id":"subjects_keywords","label":"Subjects and Keywords","entries":[{"key":"dc:subject","label":"Dc Subject","values":["Engineering","Mechanical"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier","label":"Identifier","values":["https://scholars.unh.edu/dissertation/53"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description.abstract","label":"Abstract","values":["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.
"]},{"key":"dc:title","label":"Title","values":["Numerical simulation of acoustic waves in a rectangular chamber"]}]}],"canonical_facts":{"dc:contributor":["John McHugh"],"dc:creator":["Mohd. Ghazali, Normah"],"dc:description.abstract":["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.
"],"dc:identifier":["https://scholars.unh.edu/dissertation/53"],"dc:subject":["Engineering","Mechanical"],"dc:title":["Numerical simulation of acoustic waves in a rectangular chamber"],"thesis:degree_level":["Dissertation"],"thesis:degree_name":["Doctor of Philosophy"]},"updated_at":"2026-07-24T05:21:54Z"}