ORCID

0000-0002-0924-6192

Keywords

Interface engineering; Planar heat pipes; Liquid remnants

Subject Categories

Heat Transfer, Combustion | Mechanical Engineering | Nanoscience and Nanotechnology

Abstract

Thermal management is crucial to the design of any energy producing or consuming system, and the progression of modern technology into the micro- and nanoscale with huge power-densities necessitates equally advanced thermal control technologies. Many active cooling strategies such as spray cooling, jet impingement, and pumped coolant loops can handle large heat fluxes. However, their need for additional power makes their successful integration and lifetime reliability in state-of-the-art technology challenging. Some passive cooling techniques on the other hand, such as solid-state heat spreaders and pin fins, are ill equipped to manage the thermal waste produced by cutting-edge devices. Heat pipes offer a unique solution to these challenges by combining the reliability of passive cooling architectures while capitalizing on the high heat removal capabilities of liquid-vapor phase change and transport. This dissertation presents the development of a unique planar heat pipe design engineered with a laser micro- and nano-textured wick and immiscible-liquid-remnants for enhanced cooling performance. Six different heat pipes filled with varying amounts of immiscible water and Fluorinert FC-70 were heat cycled. During heat cycling experiments, the transient local surface temperature above the heater section was recorded using a FLIR IR camera as power to the heater was ramped from 0 – 8.1 W. Results showed a dramatic reduction in the local surface temperature above the heater of 5.9  – 10 degrees Celsius as the water-FC-70 filling percentage was decreased from 100 percent to 1 percent for all tested samples. This reduction in local heater temperature at the textured hydrogel surface was accompanied by a decrease in the steady-state temperature drop across the heat pipe and an increase in the effective thermal conductivity for lower filling percentages.

Completion Date

2026

Semester

Summer

Committee Chair

Putnam, Shawn

Degree

Doctor of Philosophy (Ph.D.)

College

College of Engineering and Computer Science

Department

Mechanical and Aerospace Engineering

Format

PDF

Document Type

Dissertation

Language

English

Release Date

8-15-2027

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Available for download on Sunday, August 15, 2027

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