{"id":{"repo_id":"brunel","oai_identifier":"oai:bura.brunel.ac.uk:2438/6618"},"canonical_url":"https://search.dev.ndltd.org/etd/brunel/oai:bura.brunel.ac.uk:2438/6618","repository":{"repo_id":"brunel","name":"University of Brunel","base_url":"https://bura.brunel.ac.uk/oai/request"},"display":{"title":"The scattering of sound waves in two-dimensional ducts with discontinuities in height and material property","abstract":"Eigen-mode matching techniques offer a versatile approach for solving acoustic scattering problems in ducts. However, until recently, these techniques have been restricted to problems in which the boundary conditions contain at most one derivative, that is, Neumann, Dirichlet or Robin's conditions. Here a method is developed to solve scattering problems in ducts that are discontinuous in height and have at least one surface described by a high order boundary condition. Attention is focussed on the membrane condition, but the method can be extended to elastic plates and other higher order conditions. An original orthogonality condition is derived and used to solve two problems. Limiting cases of the results are compared with some special cases solveable by standard Fourier techniques and (for the case of no height discontinuity) the Wiener-Hopf technique.","abstract_html":"Eigen-mode matching techniques offer a versatile approach for solving acoustic scattering problems in ducts. However, until recently, these techniques have been restricted to problems in which the boundary conditions contain at most one derivative, that is, Neumann, Dirichlet or Robin's conditions. Here a method is developed to solve scattering problems in ducts that are discontinuous in height and have at least one surface described by a high order boundary condition. Attention is focussed on the membrane condition, but the method can be extended to elastic plates and other higher order conditions. An original orthogonality condition is derived and used to solve two problems. Limiting cases of the results are compared with some special cases solveable by standard Fourier techniques and (for the case of no height discontinuity) the Wiener-Hopf technique.","abstract_has_math":false,"creators":["Warren, Daniel"],"institution":"Brunel University, School of Information Systems, Computing and Mathematics","degree_name":null,"degree_level":null,"degree_discipline":null,"degree_department":null,"school":null,"contributors":[],"advisors":["Lawrie, JB"],"committee_chairs":[],"committee_members":[],"year":1999,"date_issued":"1999","date_published":"1999","updated_at":"2026-07-24T01:23:28Z","subjects":[],"languages":["en"],"rights":[],"rights_urls":[],"identifier_entries":[]},"links":{"outbound_url":"http://bura.brunel.ac.uk/handle/2438/6618","outbound_label":"Repository record","outbound_source":"dc:identifier.uri"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor.advisor","label":"Advisor","values":["Lawrie, JB"]},{"key":"dc:creator","label":"Author","values":["Warren, Daniel"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date.accessioned","label":"Dc Date Accessioned","values":["2012-09-12T14:05:28Z"]},{"key":"dc:date.available","label":"Dc Date Available","values":["2012-09-12T14:05:28Z"]},{"key":"dc:date.issued","label":"Date","values":["1999"]},{"key":"dc:publisher","label":"Institution","values":["Brunel University, School of Information Systems, Computing and Mathematics"]},{"key":"dc:type","label":"Dc Type","values":["Thesis"]}]},{"id":"language_rights","label":"Language and Rights","entries":[{"key":"dc:language.iso","label":"Language (ISO)","values":["en"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier.uri","label":"Identifier URI","values":["http://bura.brunel.ac.uk/handle/2438/6618"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description","label":"Description","values":["This thesis was submitted for the degree of Doctor of Philosophy and awarded by Brunel University."]},{"key":"dc:description.abstract","label":"Abstract","values":["Eigen-mode matching techniques offer a versatile approach for solving acoustic scattering problems in ducts. However, until recently, these techniques have been restricted to problems in which the boundary conditions contain at most one derivative, that is, Neumann, Dirichlet or Robin's conditions. Here a method is developed to solve scattering problems in ducts that are discontinuous in height and have at least one surface described by a high order boundary condition. Attention is focussed on the membrane condition, but the method can be extended to elastic plates and other higher order conditions. An original orthogonality condition is derived and used to solve two problems. Limiting cases of the results are compared with some special cases solveable by standard Fourier techniques and (for the case of no height discontinuity) the Wiener-Hopf technique."]},{"key":"dc:title","label":"Title","values":["The scattering of sound waves in two-dimensional ducts with discontinuities in height and material property"]}]}],"canonical_facts":{"dc:contributor.advisor":["Lawrie, JB"],"dc:creator":["Warren, Daniel"],"dc:date.accessioned":["2012-09-12T14:05:28Z"],"dc:date.available":["2012-09-12T14:05:28Z"],"dc:date.issued":["1999"],"dc:description":["This thesis was submitted for the degree of Doctor of Philosophy and awarded by Brunel University."],"dc:description.abstract":["Eigen-mode matching techniques offer a versatile approach for solving acoustic scattering problems in ducts. However, until recently, these techniques have been restricted to problems in which the boundary conditions contain at most one derivative, that is, Neumann, Dirichlet or Robin's conditions. Here a method is developed to solve scattering problems in ducts that are discontinuous in height and have at least one surface described by a high order boundary condition. Attention is focussed on the membrane condition, but the method can be extended to elastic plates and other higher order conditions. An original orthogonality condition is derived and used to solve two problems. Limiting cases of the results are compared with some special cases solveable by standard Fourier techniques and (for the case of no height discontinuity) the Wiener-Hopf technique."],"dc:identifier.uri":["http://bura.brunel.ac.uk/handle/2438/6618"],"dc:language.iso":["en"],"dc:publisher":["Brunel University, School of Information Systems, Computing and Mathematics"],"dc:title":["The scattering of sound waves in two-dimensional ducts with discontinuities in height and material property"],"dc:type":["Thesis"]},"updated_at":"2026-07-24T01:23:28Z"}