{"id":{"repo_id":"uiuc","oai_identifier":"oai:www.ideals.illinois.edu:2142/44481"},"canonical_url":"https://search.dev.ndltd.org/etd/uiuc/oai:www.ideals.illinois.edu:2142/44481","repository":{"repo_id":"uiuc","name":"University of Illinois - Urbana-Champaign","base_url":"https://www.ideals.illinois.edu/oai-pmh"},"display":{"title":"Measurements of heat transferred and residence time of a droplet on a hot surface","abstract":"Restriction data tranferred 2014-07-01T11:36:18-05:00 Original Data Group with Access UIUC Users [automated] Release Date: 2015-05-24 17:18:31 UTC Reason: Author requested U of Illinois access only (OA after 2yrs) in Vireo ETD system","abstract_html":"Restriction data tranferred 2014-07-01T11:36:18-05:00 Original Data Group with Access UIUC Users [automated] Release Date: 2015-05-24 17:18:31 UTC Reason: Author requested U of Illinois access only (OA after 2yrs) in Vireo ETD system","abstract_has_math":false,"creators":["Park, Ji Yong"],"institution":"University of Illinois at Urbana-Champaign","degree_name":"Ph.D.","degree_level":"Dissertation","degree_discipline":"Materials Science & Engr","degree_department":null,"school":null,"contributors":["Cahill, David G.","Granick, Steve","King, William P.","Martin, Lane W."],"advisors":[],"committee_chairs":[],"committee_members":[],"year":2013,"date_issued":"2013-05-24T22:17:39Z","date_published":"2013-05-24T22:17:39Z","updated_at":"2026-07-22T22:25:34Z","subjects":["boiling","heat transfer","residence time","bouncing droplet","hydrophobic","time domain thermoreflectance"],"languages":["en"],"rights":["Copyright 2013 Ji Yong Park"],"rights_urls":[],"identifier_entries":[]},"links":{"outbound_url":"http://hdl.handle.net/2142/44481","outbound_label":"Handle","outbound_source":"dc:identifier"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor","label":"Contributor","values":["Cahill, David G.","Granick, Steve","King, William P.","Martin, Lane W."]},{"key":"dc:creator","label":"Author","values":["Park, Ji Yong"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date","label":"Dc Date","values":["2013-05-24T22:17:39Z","2015-05-24T10:01:12Z","2013-05"]},{"key":"dc:type","label":"Dc Type","values":["text"]},{"key":"thesis:degree_discipline","label":"Discipline","values":["Materials Science & Engr"]},{"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":["boiling","heat transfer","residence time","bouncing droplet","hydrophobic","time domain thermoreflectance"]}]},{"id":"language_rights","label":"Language and Rights","entries":[{"key":"dc:language","label":"Dc Language","values":["en"]},{"key":"dc:rights","label":"Dc Rights","values":["Copyright 2013 Ji Yong Park"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier","label":"Identifier","values":["http://hdl.handle.net/2142/44481"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description","label":"Description","values":["Restriction data tranferred 2014-07-01T11:36:18-05:00 Original Data Group with Access UIUC Users [automated] Release Date: 2015-05-24 17:18:31 UTC Reason: Author requested U of Illinois access only (OA after 2yrs) in Vireo ETD system","Item marked as restricted to the 'UIUC Users [automated]' Group (id=2) by Seth Robbins (srobbins@illinois.edu) on 2013-05-24T22:19:20Z Item is restricted until 2015-05-24T22:18:31Z","U of I Only Restriction Lifted for Item 44454 on 2015-05-24T10:01:12Z.","This dissertation focuses on experimental studies of thermal transport between solid and liquid, especially between Pt(or CFx)-coated Si and water droplet, using an ultrafast pump-probe method, time-domain thermoreflectance (TDTR), combined with two-photon absorption (TPA) thermometry. I developed the technique to measure both i) the heat transfer (the amount of thermal energy transferred from hot surface to the water droplet) and ii) the residence time using the same apparatus when water droplet was in contact with a hot Si surface. I achieved a sub-msec time resolution for simultaneous measurements of the near-surface temperature (using TPA) and the effective thermal conductance (using TDTR) of the solid-liquid interface. I studied the droplet impact on both hydrophilic (Pt-coated Si) and hydrophobic (CFx-coated Si) surfaces. For the smooth hydrophilic surfaces, the amount of thermal energy transferred decreased beyond 150 oC due to droplet shattering while the residence time monotonically decreased as temperature increased. The heat flux calculated from the heat transfer and the residence time approached ~500 W cm-2 at 210 oC, which was comparable or exceeded the reported values of the critical heat flux in typical water boiling experiment. However, it only existed for a short time, on the order of 10 msec. For the patterned hydrophobic surface, I also studied the heat transfer and the kinetics of liquid-to-vapor phase transformation when the water droplet bounced off the hot surface. I found that the residence time from TDTR measurements was up to 40 times shorter than that from high-speed camera imaging; the trapped vapor at the ridge quickly moved to the center of the pattern. I also found that the contribution to heat transfer by evaporation was non-negligible at T>130 oC while the contribution to heat transfer by conduction decreased with temperature due to the short residence time. In addition, I extended the pump-probe system to the measurement of true contact area. I studied adhesion between Pt-coated Si and PDMS with pyramids array according to humidity; the humidity affects the capillary portion between Si and PDMS. Assuming that the contact area between surfaces was proportional to the effective thermal conductance of PDMS, I measured the effective thermal conductance with varying the distance between surfaces at dry (<2% RH) and humid (>50%) environments; the difference between two conditions was reported without further quantitative analysis.","Item withdrawn by Mark Zulauf (zulauf@illinois.edu) on 2012-12-18T19:34:02Z Item was in collections: University of Illinois Theses & Dissertations (ID: 1) No. of bitstreams: 1 Park_JiYong.pdf: 6877279 bytes, checksum: 5f7881d3565a4e38f668afdbe11e671b (MD5)","Made available in DSpace on 2013-05-24T22:17:39Z (GMT). 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I developed the technique to measure both i) the heat transfer (the amount of thermal energy transferred from hot surface to the water droplet) and ii) the residence time using the same apparatus when water droplet was in contact with a hot Si surface. I achieved a sub-msec time resolution for simultaneous measurements of the near-surface temperature (using TPA) and the effective thermal conductance (using TDTR) of the solid-liquid interface. I studied the droplet impact on both hydrophilic (Pt-coated Si) and hydrophobic (CFx-coated Si) surfaces. For the smooth hydrophilic surfaces, the amount of thermal energy transferred decreased beyond 150 oC due to droplet shattering while the residence time monotonically decreased as temperature increased. The heat flux calculated from the heat transfer and the residence time approached ~500 W cm-2 at 210 oC, which was comparable or exceeded the reported values of the critical heat flux in typical water boiling experiment. However, it only existed for a short time, on the order of 10 msec. For the patterned hydrophobic surface, I also studied the heat transfer and the kinetics of liquid-to-vapor phase transformation when the water droplet bounced off the hot surface. I found that the residence time from TDTR measurements was up to 40 times shorter than that from high-speed camera imaging; the trapped vapor at the ridge quickly moved to the center of the pattern. I also found that the contribution to heat transfer by evaporation was non-negligible at T>130 oC while the contribution to heat transfer by conduction decreased with temperature due to the short residence time. In addition, I extended the pump-probe system to the measurement of true contact area. I studied adhesion between Pt-coated Si and PDMS with pyramids array according to humidity; the humidity affects the capillary portion between Si and PDMS. Assuming that the contact area between surfaces was proportional to the effective thermal conductance of PDMS, I measured the effective thermal conductance with varying the distance between surfaces at dry (<2% RH) and humid (>50%) environments; the difference between two conditions was reported without further quantitative analysis.","Item withdrawn by Mark Zulauf (zulauf@illinois.edu) on 2012-12-18T19:34:02Z Item was in collections: University of Illinois Theses & Dissertations (ID: 1) No. of bitstreams: 1 Park_JiYong.pdf: 6877279 bytes, checksum: 5f7881d3565a4e38f668afdbe11e671b (MD5)","Made available in DSpace on 2013-05-24T22:17:39Z (GMT). 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