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Title:Boiling on hierarchical nanoengineered surfaces
Author(s):Fu, Wuchen
Advisor(s):Miljkovic, Nenad
Department / Program:Mechanical Sci & Engineering
Discipline:Mechanical Engineering
Degree Granting Institution:University of Illinois at Urbana-Champaign
Degree:M.S.
Genre:Thesis
Subject(s):Pool boiling
Wickability
Abstract:Boiling heat transfer can be enhanced by applying nanostructured surfaces. Past studies have investigated well-ordered, non-scalable structures to study the fundamental limitations of boiling. Here, we developed a highly scalable, three-tier hierarchical surface deposition technique to investigate the pool boiling heat transfer performance with focus on the bubble departure diameter and frequency. Ultrahigh critical heat fluxes (CHF) greater than 400 W/cm2 were obtained, corresponding to an enhancement of ≈245% compared to smooth copper surfaces. Our work reveals the existence of a linear relationship between the surface wickability and CHF enhancement. The fabrication method to obtain novel and optimized three-tier hierarchical structures for pool boiling heat transfer applications is developed. The dimension of each level of structures is optimized individually to contribute to the heat transfer enhancement, which allows us to approach the theoretical limit of pool boiling heat flux. Furthermore, our novel development of high-magnification in-liquid endoscopy for the study of bubble behavior on micro/nanostructured surfaces provides a new tool for phase change heat transfer studies.
Issue Date:2020-04-24
Type:Thesis
URI:http://hdl.handle.net/2142/108121
Rights Information:Copyright 2020 Wuchen Fu
Date Available in IDEALS:2020-08-26
Date Deposited:2020-05


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