{"id":{"repo_id":"uiuc","oai_identifier":"oai:www.ideals.illinois.edu:2142/130013"},"canonical_url":"https://search.dev.ndltd.org/etd/uiuc/oai:www.ideals.illinois.edu:2142/130013","repository":{"repo_id":"uiuc","name":"University of Illinois - Urbana-Champaign","base_url":"https://www.ideals.illinois.edu/oai-pmh"},"display":{"title":"Thermal performance analysis of next generation high performance computing data centers using waterfall diagrams","abstract":"Submission published under a 24 month embargo labeled 'U of I Access', the embargo will last until 2027-08-01","abstract_html":"Submission published under a 24 month embargo labeled 'U of I Access', the embargo will last until 2027-08-01","abstract_has_math":false,"creators":["Lee, Donggun"],"institution":"University of Illinois Urbana-Champaign","degree_name":"M.S.","degree_level":"Thesis","degree_discipline":"Mechanical Engineering","degree_department":null,"school":null,"contributors":["Miljkovic, Nenad"],"advisors":[],"committee_chairs":[],"committee_members":[],"year":2025,"date_issued":"2025-07-07","date_published":"2025-07-07","updated_at":"2026-07-22T22:25:06Z","subjects":["Data Center","Liquid Cooling","Thermal Management"],"languages":["en","eng"],"rights":["Copyright 2025 Donggun Lee"],"rights_urls":[],"identifier_entries":[]},"links":{"outbound_url":"https://hdl.handle.net/2142/130013","outbound_label":"Handle","outbound_source":"dc:identifier"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor","label":"Contributor","values":["Miljkovic, Nenad"]},{"key":"dc:creator","label":"Author","values":["Lee, Donggun"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date","label":"Dc Date","values":["2025-07-07","2025-08"]},{"key":"dc:type","label":"Dc Type","values":["text"]},{"key":"thesis:degree_discipline","label":"Discipline","values":["Mechanical Engineering"]},{"key":"thesis:degree_level","label":"Degree Level","values":["Thesis"]},{"key":"thesis:degree_name","label":"Degree Name","values":["M.S."]},{"key":"thesis:institution_name","label":"Thesis Institution Name","values":["University of Illinois Urbana-Champaign"]}]},{"id":"subjects_keywords","label":"Subjects and Keywords","entries":[{"key":"dc:subject","label":"Dc Subject","values":["Data Center","Liquid Cooling","Thermal Management"]}]},{"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 2025 Donggun Lee"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier","label":"Identifier","values":["https://hdl.handle.net/2142/130013"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description","label":"Description","values":["Submission published under a 24 month embargo labeled 'U of I Access', the embargo will last until 2027-08-01","The student, Donggun Lee, accepted the attached license on 2025-06-26 at 12:41.","The student, Donggun Lee, submitted this Thesis for approval on 2025-06-26 at 12:49.","This Thesis was approved for publication on 2025-07-07 at 12:41.","DSpace SAF Submission Ingestion Package generated from Vireo submission #22371 on 2025-10-21 at 10:05:35","Thermal management in high-density computing data centers is crucial for maintaining performance, reliability, and energy efficiency. As computing power demands surge, traditional air-cooling methods face limitations in handling increasing heat loads, while liquid cooling offers a feasible solution. However, a system-level metric and analysis assessing the energy efficiency of liquid cooling remains absent. This paper introduces a novel waterfall diagram (WFD) framework to provide a comprehensive system-level analysis of liquid cooling performance. The WFD evaluates energy efficiency using total-power usage effectiveness (TUE) derived from analytical calculations. A comparative analysis of coolant distribution unit (CDU) designs identified the 3U CDU architecture as the most suitable configuration for WFD analysis due to its optimal power consumption, TUE, and power density. The WFD analysis also incorporates the Sankey and heat load diagrams to visualize energy flow and heat load accumulation across the cooling system. Results indicate that the secondary side yields the highest pressure drop, which emphasizes opportunities for hydraulic performance optimization. In addition, at the component level, the cooler’s low pressure drop highlights its energy efficiency while, at the system level, the cooler and tube connections make a significant contribution to system TUE, suggesting areas of improvement for energy efficiency. This framework relies on analytical methods without empirical validation and assumes steady-state conditions, which may limit its applicability. Future work should focus on experimental validation and transient thermal analysis. Additionally, the WFD methodology can be extended to different data center cooling methods and other thermal management systems such as hybrid air-liquid cooling, immersion cooling, HVAC, and battery cooling."]},{"key":"dc:format","label":"Dc Format","values":["application/pdf"]},{"key":"dc:title","label":"Title","values":["Thermal performance analysis of next generation high performance computing data centers using waterfall diagrams"]}]}],"canonical_facts":{"dc:contributor":["Miljkovic, Nenad"],"dc:creator":["Lee, Donggun"],"dc:date":["2025-07-07","2025-08"],"dc:description":["Submission published under a 24 month embargo labeled 'U of I Access', the embargo will last until 2027-08-01","The student, Donggun Lee, accepted the attached license on 2025-06-26 at 12:41.","The student, Donggun Lee, submitted this Thesis for approval on 2025-06-26 at 12:49.","This Thesis was approved for publication on 2025-07-07 at 12:41.","DSpace SAF Submission Ingestion Package generated from Vireo submission #22371 on 2025-10-21 at 10:05:35","Thermal management in high-density computing data centers is crucial for maintaining performance, reliability, and energy efficiency. As computing power demands surge, traditional air-cooling methods face limitations in handling increasing heat loads, while liquid cooling offers a feasible solution. However, a system-level metric and analysis assessing the energy efficiency of liquid cooling remains absent. This paper introduces a novel waterfall diagram (WFD) framework to provide a comprehensive system-level analysis of liquid cooling performance. The WFD evaluates energy efficiency using total-power usage effectiveness (TUE) derived from analytical calculations. A comparative analysis of coolant distribution unit (CDU) designs identified the 3U CDU architecture as the most suitable configuration for WFD analysis due to its optimal power consumption, TUE, and power density. The WFD analysis also incorporates the Sankey and heat load diagrams to visualize energy flow and heat load accumulation across the cooling system. Results indicate that the secondary side yields the highest pressure drop, which emphasizes opportunities for hydraulic performance optimization. In addition, at the component level, the cooler’s low pressure drop highlights its energy efficiency while, at the system level, the cooler and tube connections make a significant contribution to system TUE, suggesting areas of improvement for energy efficiency. This framework relies on analytical methods without empirical validation and assumes steady-state conditions, which may limit its applicability. Future work should focus on experimental validation and transient thermal analysis. Additionally, the WFD methodology can be extended to different data center cooling methods and other thermal management systems such as hybrid air-liquid cooling, immersion cooling, HVAC, and battery cooling."],"dc:format":["application/pdf"],"dc:identifier":["https://hdl.handle.net/2142/130013"],"dc:language":["en","eng"],"dc:rights":["Copyright 2025 Donggun Lee"],"dc:subject":["Data Center","Liquid Cooling","Thermal Management"],"dc:title":["Thermal performance analysis of next generation high performance computing data centers using waterfall diagrams"],"dc:type":["text"],"thesis:degree_discipline":["Mechanical Engineering"],"thesis:degree_level":["Thesis"],"thesis:degree_name":["M.S."],"thesis:institution_name":["University of Illinois Urbana-Champaign"]},"updated_at":"2026-07-22T22:25:06Z"}