ORCID Identifier(s)

0000-0002-4161-0695

Graduation Semester and Year

2017

Language

English

Document Type

Thesis

Degree Name

Master of Science in Mechanical Engineering

Department

Mechanical and Aerospace Engineering

First Advisor

Dereje Agonafer

Abstract

Emerging technologies are pushing the limits by reducing the size of the nodes, raising the heat densities of packages thereby demanding better thermal management. The cooling power requirement increases drastically when air is used as the cooling medium in high power density servers as air has a low heat transfer coefficient. Very viable replacements for air as the cooling medium are water and oil. Oil is not as widely used as it has its own disadvantages when compared to water. Water has appreciably higher heat transfer coefficient, which helps it to remove heat from the server at a much faster rate when compared to air. Finally, the abundant availability of water makes it the perfect replacement for air in high power electronic systems. Another issue unique to multichip scale modules is the uneven heat generation by various packages of the module, usually creating localized high temperature regions called "hotspots". This issue can be addressed by using dynamic cold plates. Dynamic cold plates are designed to have sections isolated from each other to cool multichip scale modules. In order to reduce pumping power for liquid cooling, dynamic cold plates can distribute flow between various sections within the cold plate based on cooling requirement in each section of the module. Each section of the cold plate has a dedicated flow control device, that can sense temperature and regulate flow rate accordingly. This thesis presents the flow analysis of a self-regulating flow control device (FCD) designed for cooling a 160 W module. The flow control device controls flow by the use of an axially rotating butterfly valve mechanism. Linearization of the flow with respect to damper angle is studied by modifying the dimensional ratios of the rectangular cross section of the FCD. Pressure drop and flow rate characterization is done for the FCD. Effects of fluid flow on the structural integrity of the FCD as a whole is also studied.

Keywords

Flow control device, Linearization, Data center cooling, Nitinol, Rectangular cross sectioned valve, Server cooling

Disciplines

Aerospace Engineering | Engineering | Mechanical Engineering

Comments

Degree granted by The University of Texas at Arlington

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