2026-09-20T21:35:34Z https://www.ideals.illinois.edu/oai-pmh

oai:www.ideals.illinois.edu:2142/132682 2026-03-24 col_2142_5131 col_2142_14787 com_2142_5130 com_2142_9630 com_2142_234

application/pdf en text Submission published under a 24 month embargo labeled 'U of I Access', the embargo will last until 2027-12-01 The student, Yiyang Chen, accepted the attached license on 2025-12-02 at 14:56. The student, Yiyang Chen, submitted this Thesis for approval on 2025-12-02 at 15:04. This Thesis was approved for publication on 2025-12-03 at 20:39. DSpace SAF Submission Ingestion Package generated from Vireo submission #23023 on 2026-02-19 at 18:46:32 Design guidelines of laser structured surfaces for enhanced pool boiling heat transfer Chen, Yiyang 2025-12-03 Miljkovic, Nenad Pool Boiling Refrigerant Laser eng Boiling enhancement has emerged as a salient pathway to improve energy efficiency and reduce operating costs. In this work, we strengthen external pool boiling of R-1336mzz(Z) on tube exteriors by optimizing laser texturing recipes. Systematic adjustment of laser parameters enables deterministic control of surface morphology, with distinct parameter sets imparting characteristically different topographies. Guided by Hsu’s model, we select processing conditions that yield a broad distribution of re-entrant cavities whose sizes fall within the activation window while maintaining a high areal nucleation site density. The results show that, throughout the nucleate boiling regime, the HTC enhancement ratio of the laser textured tube exceeds 4 compared to the plain Cu tube. High speed visualization corroborates this gain by revealing dense bubble departure associated with the elevated population of active sites. These findings provide actionable guidance for the design and fabrication of laser processed surfaces for boiling applications. 2025-12 Thesis https://hdl.handle.net/2142/132682 Copyright 2025 Yiyang Chen Mechanical Sci & Engineering Mechanical Engineering University of Illinois Urbana-Champaign M.S. Thesis