{"id":{"repo_id":"uiuc","oai_identifier":"oai:www.ideals.illinois.edu:2142/22851"},"canonical_url":"https://search.dev.ndltd.org/etd/uiuc/oai:www.ideals.illinois.edu:2142/22851","repository":{"repo_id":"uiuc","name":"University of Illinois - Urbana-Champaign","base_url":"https://www.ideals.illinois.edu/oai-pmh"},"display":{"title":"Scattering of an ultrasonic beam from a curved interface","abstract":"We calculate the wavefield scattered from a circular fluid-solid interface when it is struck by a well collimated ultrasonic beam, emitted from a transducer in the fluid. Both convex and concave interfaces (as seen from source) are considered. The radius of curvature of the interface is assumed to be sufficiently large that only reflection, transmission and the excitation of a leaky Rayleigh wave need be considered; the incident beam does not graze the interface. The incident beam is modeled as a two-dimensional wavefield whose initial profile is either Gaussian or rectangular. In both cases the aperture is assumed to be sufficiently large (in wavelengths) that a well collimated beam is radiated, and the interface is assumed to lie close enough to the aperture that it is struck by a wavefield that has not yet evolved into a cylindrical wave. The scattered wavefields are represented as multiple integrals and are evaluated asymptotically. Of particular interest is the formation of caustics and cusps by the reflected and transmitted rectangular beam when it is scattered by the concave interface. Also of particular interest is the propagation and radiation into the fluid of the Rayleigh wave excited on the convex interface.","abstract_html":"We calculate the wavefield scattered from a circular fluid-solid interface when it is struck by a well collimated ultrasonic beam, emitted from a transducer in the fluid. Both convex and concave interfaces (as seen from source) are considered. The radius of curvature of the interface is assumed to be sufficiently large that only reflection, transmission and the excitation of a leaky Rayleigh wave need be considered; the incident beam does not graze the interface. The incident beam is modeled as a two-dimensional wavefield whose initial profile is either Gaussian or rectangular. In both cases the aperture is assumed to be sufficiently large (in wavelengths) that a well collimated beam is radiated, and the interface is assumed to lie close enough to the aperture that it is struck by a wavefield that has not yet evolved into a cylindrical wave. The scattered wavefields are represented as multiple integrals and are evaluated asymptotically. Of particular interest is the formation of caustics and cusps by the reflected and transmitted rectangular beam when it is scattered by the concave interface. Also of particular interest is the propagation and radiation into the fluid of the Rayleigh wave excited on the convex interface.","abstract_has_math":false,"creators":["Choi, Hyung-Chul"],"institution":"University of Illinois at Urbana-Champaign","degree_name":"Ph.D.","degree_level":"Dissertation","degree_discipline":"Engineering, Mechanical","degree_department":null,"school":null,"contributors":["Harris, John G."],"advisors":[],"committee_chairs":[],"committee_members":[],"year":2011,"date_issued":"2011-05-07T13:53:36Z","date_published":"2011-05-07T13:53:36Z","updated_at":"2026-07-22T22:25:20Z","subjects":["Engineering, Mechanical"],"languages":["eng"],"rights":["Copyright 1989 Choi, Hyung-Chul"],"rights_urls":[],"identifier_entries":[{"key":"dc:identifier","label":"Identifier","values":["AAI8916228","(UMI)AAI8916228"],"render_values":[{"text":"AAI8916228","href":null,"code":true},{"text":"(UMI)AAI8916228","href":null,"code":true}]}]},"links":{"outbound_url":"http://hdl.handle.net/2142/22851","outbound_label":"Handle","outbound_source":"dc:identifier"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor","label":"Contributor","values":["Harris, John G."]},{"key":"dc:creator","label":"Author","values":["Choi, Hyung-Chul"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date","label":"Dc Date","values":["2011-05-07T13:53:36Z","10000-01-01","1989"]},{"key":"dc:type","label":"Dc Type","values":["text"]},{"key":"thesis:degree_discipline","label":"Discipline","values":["Engineering, Mechanical"]},{"key":"thesis:degree_level","label":"Degree Level","values":["Dissertation"]},{"key":"thesis:degree_name","label":"Degree Name","values":["Ph.D."]},{"key":"thesis:institution_name","label":"Thesis Institution Name","values":["University of Illinois at Urbana-Champaign"]}]},{"id":"subjects_keywords","label":"Subjects and Keywords","entries":[{"key":"dc:subject","label":"Dc Subject","values":["Engineering, Mechanical"]}]},{"id":"language_rights","label":"Language and Rights","entries":[{"key":"dc:language","label":"Dc Language","values":["eng"]},{"key":"dc:rights","label":"Dc Rights","values":["Copyright 1989 Choi, Hyung-Chul"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier","label":"Identifier","values":["http://hdl.handle.net/2142/22851","AAI8916228","(UMI)AAI8916228"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description","label":"Description","values":["We calculate the wavefield scattered from a circular fluid-solid interface when it is struck by a well collimated ultrasonic beam, emitted from a transducer in the fluid. Both convex and concave interfaces (as seen from source) are considered. The radius of curvature of the interface is assumed to be sufficiently large that only reflection, transmission and the excitation of a leaky Rayleigh wave need be considered; the incident beam does not graze the interface. The incident beam is modeled as a two-dimensional wavefield whose initial profile is either Gaussian or rectangular. In both cases the aperture is assumed to be sufficiently large (in wavelengths) that a well collimated beam is radiated, and the interface is assumed to lie close enough to the aperture that it is struck by a wavefield that has not yet evolved into a cylindrical wave. The scattered wavefields are represented as multiple integrals and are evaluated asymptotically. Of particular interest is the formation of caustics and cusps by the reflected and transmitted rectangular beam when it is scattered by the concave interface. Also of particular interest is the propagation and radiation into the fluid of the Rayleigh wave excited on the convex interface.","Made available in DSpace on 2011-05-07T13:53:36Z (GMT). No. of bitstreams: 2 license.txt: 4922 bytes, checksum: 910b249b4beec47e7ab768910c8f966f (MD5) 8916228.pdf: 2852960 bytes, checksum: 3670a1b5563924cba624c43121a0b474 (MD5) Previous issue date: 1989","Item marked as restricted to the 'UIUC Users [automated]' Group (id=2) by Howard Ding (hding2@illinois.edu) on 2011-05-07T15:00:27Z Item is restricted indefinitely.","Restriction data tranferred 2014-07-01T11:28:36-05:00 Original Data Group with Access UIUC Users [automated] Release Date: none Reason: ETDs are only available to UIUC Users without author permission","ETDs are only available to UIUC Users without author permission","U of I Only"]},{"key":"dc:title","label":"Title","values":["Scattering of an ultrasonic beam from a curved interface"]}]}],"canonical_facts":{"dc:contributor":["Harris, John G."],"dc:creator":["Choi, Hyung-Chul"],"dc:date":["2011-05-07T13:53:36Z","10000-01-01","1989"],"dc:description":["We calculate the wavefield scattered from a circular fluid-solid interface when it is struck by a well collimated ultrasonic beam, emitted from a transducer in the fluid. Both convex and concave interfaces (as seen from source) are considered. The radius of curvature of the interface is assumed to be sufficiently large that only reflection, transmission and the excitation of a leaky Rayleigh wave need be considered; the incident beam does not graze the interface. The incident beam is modeled as a two-dimensional wavefield whose initial profile is either Gaussian or rectangular. In both cases the aperture is assumed to be sufficiently large (in wavelengths) that a well collimated beam is radiated, and the interface is assumed to lie close enough to the aperture that it is struck by a wavefield that has not yet evolved into a cylindrical wave. The scattered wavefields are represented as multiple integrals and are evaluated asymptotically. Of particular interest is the formation of caustics and cusps by the reflected and transmitted rectangular beam when it is scattered by the concave interface. Also of particular interest is the propagation and radiation into the fluid of the Rayleigh wave excited on the convex interface.","Made available in DSpace on 2011-05-07T13:53:36Z (GMT). No. of bitstreams: 2 license.txt: 4922 bytes, checksum: 910b249b4beec47e7ab768910c8f966f (MD5) 8916228.pdf: 2852960 bytes, checksum: 3670a1b5563924cba624c43121a0b474 (MD5) Previous issue date: 1989","Item marked as restricted to the 'UIUC Users [automated]' Group (id=2) by Howard Ding (hding2@illinois.edu) on 2011-05-07T15:00:27Z Item is restricted indefinitely.","Restriction data tranferred 2014-07-01T11:28:36-05:00 Original Data Group with Access UIUC Users [automated] Release Date: none Reason: ETDs are only available to UIUC Users without author permission","ETDs are only available to UIUC Users without author permission","U of I Only"],"dc:identifier":["http://hdl.handle.net/2142/22851","AAI8916228","(UMI)AAI8916228"],"dc:language":["eng"],"dc:rights":["Copyright 1989 Choi, Hyung-Chul"],"dc:subject":["Engineering, Mechanical"],"dc:title":["Scattering of an ultrasonic beam from a curved interface"],"dc:type":["text"],"thesis:degree_discipline":["Engineering, Mechanical"],"thesis:degree_level":["Dissertation"],"thesis:degree_name":["Ph.D."],"thesis:institution_name":["University of Illinois at Urbana-Champaign"]},"updated_at":"2026-07-22T22:25:20Z"}