Numerical Modeling of Capillary Flow in a Novel Micropillar Geometry for Applications in Passive Two-Phase Cooling Systems

• Main Author: Byers, Ashley
• Language: EN
• Published: Southern Illinois University at Edwardsville 2016
• Subjects: Mechanical engineering
• Online Access: http://pqdtopen.proquest.com/#viewpdf?dispub=10000329

<p> Microstructures have become an increasingly popular method for two phase heat removal in electronics. Maximizing capillary pressure and thermal conductivity are the most direct methods for increasing heat removal in capillary-driven, two-phase cooling systems. It is well known that closely packed wicking structures produce a higher capillary pressure. However, this adversely affects the permeability of the fluid inhibiting its ability to flow, thus reducing heat removal capability. This research aims to address this issue. A numerical model is implemented with a novel micropillar structure to increase capillary pressure while maintaining necessary permeability. These novel micropillar structures have a larger spacing at the base of the micropillar to provide a higher liquid permeability and mushroom-like structure on the top surface of the micropillars with a smaller spacing to provide a greater capillary pressure. The results indicate that the liquid column rise of the mushroom-like structures is 6 times higher than standard micropillar arrays for a contact angle of 50&deg;.</p>