{"id":{"repo_id":"uiuc","oai_identifier":"oai:www.ideals.illinois.edu:2142/85133"},"canonical_url":"https://search.dev.ndltd.org/etd/uiuc/oai:www.ideals.illinois.edu:2142/85133","repository":{"repo_id":"uiuc","name":"University of Illinois - Urbana-Champaign","base_url":"https://www.ideals.illinois.edu/oai-pmh"},"display":{"title":"Hydrodynamic Instability of Fluid Flow Through Homogeneous Porous Media","abstract":"To examine mechanisms for the production of large-amplitude, steady disturbances at elevated Reynolds number, the effective porosity of the medium is reconsidered. Experimental results and detailed microscale flow simulations indicate that significant regions of flow separation exist around and downstream of the contact points of the particles in the porous medium. This results in a decrease in the effective porosity of the medium as Reynolds number is increased, insofar as transport of mass and momentum are concerned, and this phenomenon has not been addressed in prior experimental or computational studies. A new porosity-based streamfunction transformation is introduced, similar in aspects to the density-based transformations used in compressible flows. The porosity is then assumed to be a function of flow Reynolds number. The equation for the linearized disturbance streamfunction then depends on the derivative of porosity with respect to pore Reynolds number evaluated at the mean flow conditions. Flow in the porous media system is found to be spatially unstable for relatively small negative values of the porosity derivative, thus providing a new potential mechanism for observed instabilities.","abstract_html":"To examine mechanisms for the production of large-amplitude, steady disturbances at elevated Reynolds number, the effective porosity of the medium is reconsidered. Experimental results and detailed microscale flow simulations indicate that significant regions of flow separation exist around and downstream of the contact points of the particles in the porous medium. This results in a decrease in the effective porosity of the medium as Reynolds number is increased, insofar as transport of mass and momentum are concerned, and this phenomenon has not been addressed in prior experimental or computational studies. A new porosity-based streamfunction transformation is introduced, similar in aspects to the density-based transformations used in compressible flows. The porosity is then assumed to be a function of flow Reynolds number. The equation for the linearized disturbance streamfunction then depends on the derivative of porosity with respect to pore Reynolds number evaluated at the mean flow conditions. Flow in the porous media system is found to be spatially unstable for relatively small negative values of the porosity derivative, thus providing a new potential mechanism for observed instabilities.","abstract_has_math":false,"creators":["Low, Corwyn Eng Kong"],"institution":"University of Illinois at Urbana-Champaign","degree_name":"Ph.D.","degree_level":"Dissertation","degree_discipline":"Aerospace Engineering","degree_department":null,"school":null,"contributors":["Beddini, Robert A."],"advisors":[],"committee_chairs":[],"committee_members":[],"year":2015,"date_issued":"2015-09-25T22:34:33Z","date_published":"2015-09-25T22:34:33Z","updated_at":"2026-07-22T22:26:24Z","subjects":["Physics, Fluid and Plasma"],"languages":["eng"],"rights":[],"rights_urls":[],"identifier_entries":[{"key":"dc:identifier","label":"Identifier","values":["(MiAaPQ)AAI9955647"],"render_values":[{"text":"(MiAaPQ)AAI9955647","href":null,"code":true}]}]},"links":{"outbound_url":"http://hdl.handle.net/2142/85133","outbound_label":"Handle","outbound_source":"dc:identifier"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor","label":"Contributor","values":["Beddini, Robert A."]},{"key":"dc:creator","label":"Author","values":["Low, Corwyn Eng Kong"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date","label":"Dc Date","values":["2015-09-25T22:34:33Z","10000-01-01","2000"]},{"key":"dc:type","label":"Dc Type","values":["text"]},{"key":"thesis:degree_discipline","label":"Discipline","values":["Aerospace Engineering"]},{"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":["Physics, Fluid and Plasma"]}]},{"id":"language_rights","label":"Language and Rights","entries":[{"key":"dc:language","label":"Dc Language","values":["eng"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier","label":"Identifier","values":["http://hdl.handle.net/2142/85133","(MiAaPQ)AAI9955647"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description","label":"Description","values":["To examine mechanisms for the production of large-amplitude, steady disturbances at elevated Reynolds number, the effective porosity of the medium is reconsidered. Experimental results and detailed microscale flow simulations indicate that significant regions of flow separation exist around and downstream of the contact points of the particles in the porous medium. This results in a decrease in the effective porosity of the medium as Reynolds number is increased, insofar as transport of mass and momentum are concerned, and this phenomenon has not been addressed in prior experimental or computational studies. A new porosity-based streamfunction transformation is introduced, similar in aspects to the density-based transformations used in compressible flows. The porosity is then assumed to be a function of flow Reynolds number. The equation for the linearized disturbance streamfunction then depends on the derivative of porosity with respect to pore Reynolds number evaluated at the mean flow conditions. Flow in the porous media system is found to be spatially unstable for relatively small negative values of the porosity derivative, thus providing a new potential mechanism for observed instabilities.","Made available in DSpace on 2015-09-25T22:34:33Z (GMT). No. of bitstreams: 2 license.txt: 4848 bytes, checksum: 96035ab3f5e1c23cc7138a224ce498bd (MD5) 9955647.pdf: 4136052 bytes, checksum: 1656c598eb71df28c36263116653ec0b (MD5) Previous issue date: 2000","Embargo set by: Seth Robbins for item 86414 Lift date: Forever Reason: Restricted to the U of I community idenfinitely during batch ingest of legacy ETDs","Restricted to the U of I community idenfinitely during batch ingest of legacy ETDs","U of I Only","100 p.","Thesis (Ph.D.)--University of Illinois at Urbana-Champaign, 2000."]},{"key":"dc:title","label":"Title","values":["Hydrodynamic Instability of Fluid Flow Through Homogeneous Porous Media"]}]}],"canonical_facts":{"dc:contributor":["Beddini, Robert A."],"dc:creator":["Low, Corwyn Eng Kong"],"dc:date":["2015-09-25T22:34:33Z","10000-01-01","2000"],"dc:description":["To examine mechanisms for the production of large-amplitude, steady disturbances at elevated Reynolds number, the effective porosity of the medium is reconsidered. Experimental results and detailed microscale flow simulations indicate that significant regions of flow separation exist around and downstream of the contact points of the particles in the porous medium. This results in a decrease in the effective porosity of the medium as Reynolds number is increased, insofar as transport of mass and momentum are concerned, and this phenomenon has not been addressed in prior experimental or computational studies. A new porosity-based streamfunction transformation is introduced, similar in aspects to the density-based transformations used in compressible flows. The porosity is then assumed to be a function of flow Reynolds number. The equation for the linearized disturbance streamfunction then depends on the derivative of porosity with respect to pore Reynolds number evaluated at the mean flow conditions. Flow in the porous media system is found to be spatially unstable for relatively small negative values of the porosity derivative, thus providing a new potential mechanism for observed instabilities.","Made available in DSpace on 2015-09-25T22:34:33Z (GMT). No. of bitstreams: 2 license.txt: 4848 bytes, checksum: 96035ab3f5e1c23cc7138a224ce498bd (MD5) 9955647.pdf: 4136052 bytes, checksum: 1656c598eb71df28c36263116653ec0b (MD5) Previous issue date: 2000","Embargo set by: Seth Robbins for item 86414 Lift date: Forever Reason: Restricted to the U of I community idenfinitely during batch ingest of legacy ETDs","Restricted to the U of I community idenfinitely during batch ingest of legacy ETDs","U of I Only","100 p.","Thesis (Ph.D.)--University of Illinois at Urbana-Champaign, 2000."],"dc:identifier":["http://hdl.handle.net/2142/85133","(MiAaPQ)AAI9955647"],"dc:language":["eng"],"dc:subject":["Physics, Fluid and Plasma"],"dc:title":["Hydrodynamic Instability of Fluid Flow Through Homogeneous Porous Media"],"dc:type":["text"],"thesis:degree_discipline":["Aerospace Engineering"],"thesis:degree_level":["Dissertation"],"thesis:degree_name":["Ph.D."],"thesis:institution_name":["University of Illinois at Urbana-Champaign"]},"updated_at":"2026-07-22T22:26:24Z"}