{"id":{"repo_id":"uiuc","oai_identifier":"oai:www.ideals.illinois.edu:2142/117536"},"canonical_url":"https://search.dev.ndltd.org/etd/uiuc/oai:www.ideals.illinois.edu:2142/117536","repository":{"repo_id":"uiuc","name":"University of Illinois - Urbana-Champaign","base_url":"https://www.ideals.illinois.edu/oai-pmh"},"display":{"title":"Structured surface enhanced flow boiling","abstract":"Submission published under a 24 month embargo labeled 'Closed Access', the embargo will last until 2024-12-01","abstract_html":"Submission published under a 24 month embargo labeled 'Closed Access', the embargo will last until 2024-12-01","abstract_has_math":false,"creators":["Nithin Vinod Upot, -"],"institution":"University of Illinois at Urbana-Champaign","degree_name":"Ph.D.","degree_level":"Dissertation","degree_discipline":"Mechanical Engineering","degree_department":null,"school":null,"contributors":["Miljkovic, Nenad","Jacobi, Anthony","Elbel, Stefan","Banerjee , Arijit"],"advisors":[],"committee_chairs":[],"committee_members":[],"year":2022,"date_issued":"2022-12","date_published":"2022-12","updated_at":"2026-07-22T22:24:56Z","subjects":["Boiling","Structures: Scalable"],"languages":["en","eng"],"rights":["Copyright 2022 Nithin Vinod Upot"],"rights_urls":[],"identifier_entries":[]},"links":{"outbound_url":"https://hdl.handle.net/2142/117536","outbound_label":"Handle","outbound_source":"dc:identifier"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor","label":"Contributor","values":["Miljkovic, Nenad","Jacobi, Anthony","Elbel, Stefan","Banerjee , Arijit"]},{"key":"dc:creator","label":"Author","values":["Nithin Vinod Upot, -"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date","label":"Dc Date","values":["2022-12","2022-10-11"]},{"key":"dc:type","label":"Dc Type","values":["text","Thesis"]},{"key":"thesis:degree_discipline","label":"Discipline","values":["Mechanical 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":["Boiling","Structures: Scalable"]}]},{"id":"language_rights","label":"Language and Rights","entries":[{"key":"dc:language","label":"Dc Language","values":["en","eng"]},{"key":"dc:rights","label":"Dc Rights","values":["Copyright 2022 Nithin Vinod Upot"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier","label":"Identifier","values":["https://hdl.handle.net/2142/117536"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description","label":"Description","values":["Submission published under a 24 month embargo labeled 'Closed Access', the embargo will last until 2024-12-01","The student, - Nithin Vinod Upot, accepted the attached license on 2022-10-05 at 11:47.","The student, - Nithin Vinod Upot, submitted this Dissertation for approval on 2022-10-05 at 12:02.","This Dissertation was approved for publication on 2022-10-11 at 11:16.","DSpace SAF Submission Ingestion Package generated from Vireo submission #18511 on 2023-04-12 at 11:34:39","Flow boiling is prevalant in a variety of industrial sectors such as thermal management of electronics, automotive and off-road vehicles, distillation, chemical synthesis, desalination, thermoelectric power generation, refrigeration, and cryogenics since it offers the dual advantage of near-isothermal operation, and ultra-efficient energy transfer. Although the flow boiling heat transfer coefficient, a characteristic measure of the efficiency of heat transfer, is higher when compared to other modes of thermal exchange such as single phase flow, a vast amount of work has been done in the recent past to further enhance two-phase heat transfer coefficients via surface-structuring techniques. However, the majority of such studies suffer from limitations of being difficult to scale, not being characterized for durability, being difficult to manufacture on typical heat exchanger materials or having typically been studied with water as the working fluid. To address these gaps, this dissertation focuses on development of scalable fabrication methods to enhance effective heat transfer coefficients for metal-based heat exchangers with refrigerants as the working fluid. We begin by fabricating internal micron scale and nanoscale structures on the internal surface of an aluminum tube and demonstrate enhancements in heat transfer coefficients for the microstructured surface. Building on these findings, we extend the microstructuring techniques to copper and stainless-steel to examine surface-structuring enabled heat transfer coefficient enhancements. We then evaluate enhancements on existing enhanced tubes by microstructuring finned aluminum tubes through crystallographic chemical etching and demonstrate improvements in thermal performance. Finally, predictive mechanisms for heat transfer coefficients are examined and an artificial neural network is developed for high-accuracy HTC prediction. The insights presented in this thesis help in potential applicability of the demonstrated microstructuring techniques to full-scale heat exchangers."]},{"key":"dc:format","label":"Dc Format","values":["application/pdf"]},{"key":"dc:title","label":"Title","values":["Structured surface enhanced flow boiling"]}]}],"canonical_facts":{"dc:contributor":["Miljkovic, Nenad","Jacobi, Anthony","Elbel, Stefan","Banerjee , Arijit"],"dc:creator":["Nithin Vinod Upot, -"],"dc:date":["2022-12","2022-10-11"],"dc:description":["Submission published under a 24 month embargo labeled 'Closed Access', the embargo will last until 2024-12-01","The student, - Nithin Vinod Upot, accepted the attached license on 2022-10-05 at 11:47.","The student, - Nithin Vinod Upot, submitted this Dissertation for approval on 2022-10-05 at 12:02.","This Dissertation was approved for publication on 2022-10-11 at 11:16.","DSpace SAF Submission Ingestion Package generated from Vireo submission #18511 on 2023-04-12 at 11:34:39","Flow boiling is prevalant in a variety of industrial sectors such as thermal management of electronics, automotive and off-road vehicles, distillation, chemical synthesis, desalination, thermoelectric power generation, refrigeration, and cryogenics since it offers the dual advantage of near-isothermal operation, and ultra-efficient energy transfer. Although the flow boiling heat transfer coefficient, a characteristic measure of the efficiency of heat transfer, is higher when compared to other modes of thermal exchange such as single phase flow, a vast amount of work has been done in the recent past to further enhance two-phase heat transfer coefficients via surface-structuring techniques. However, the majority of such studies suffer from limitations of being difficult to scale, not being characterized for durability, being difficult to manufacture on typical heat exchanger materials or having typically been studied with water as the working fluid. To address these gaps, this dissertation focuses on development of scalable fabrication methods to enhance effective heat transfer coefficients for metal-based heat exchangers with refrigerants as the working fluid. We begin by fabricating internal micron scale and nanoscale structures on the internal surface of an aluminum tube and demonstrate enhancements in heat transfer coefficients for the microstructured surface. Building on these findings, we extend the microstructuring techniques to copper and stainless-steel to examine surface-structuring enabled heat transfer coefficient enhancements. We then evaluate enhancements on existing enhanced tubes by microstructuring finned aluminum tubes through crystallographic chemical etching and demonstrate improvements in thermal performance. Finally, predictive mechanisms for heat transfer coefficients are examined and an artificial neural network is developed for high-accuracy HTC prediction. The insights presented in this thesis help in potential applicability of the demonstrated microstructuring techniques to full-scale heat exchangers."],"dc:format":["application/pdf"],"dc:identifier":["https://hdl.handle.net/2142/117536"],"dc:language":["en","eng"],"dc:rights":["Copyright 2022 Nithin Vinod Upot"],"dc:subject":["Boiling","Structures: Scalable"],"dc:title":["Structured surface enhanced flow boiling"],"dc:type":["text","Thesis"],"thesis:degree_discipline":["Mechanical Engineering"],"thesis:degree_level":["Dissertation"],"thesis:degree_name":["Ph.D."],"thesis:institution_name":["University of Illinois at Urbana-Champaign"]},"updated_at":"2026-07-22T22:24:56Z"}