Analytical solutions of heat spreading resistance from a heat source on a finite substrate with isothermal or convective surfaces

Persistent Link:
http://hdl.handle.net/10150/282385
Title:
Analytical solutions of heat spreading resistance from a heat source on a finite substrate with isothermal or convective surfaces
Author:
Kabir, Humayun, 1963-
Issue Date:
1997
Publisher:
The University of Arizona.
Rights:
Copyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author.
Abstract:
The objective of this dissertation is to present the analytical solutions to the heat spreading problems that arise due to a flux specified circular heat source on a finite thickness substrate with isothermal or convective surfaces. The solutions to heat spreading resistance of these problems are obtained for the first time by the exact treatment of the mixed boundary conditions present on the substrate at the heat source side. In the case of heat spreading through a substrate with isothermal surfaces the solution method utilizes the two-dimensional axisymmetric equation of thermal conduction allowing for the convective cooling over source region. In the absence of convection over the source, it is shown that the total thermal resistance is composed of spreading resistance of an otherwise isothermal substrate and a correction due to inhomogeneous substrate thermal boundary condition. The application of the method of superposition elucidates the exact definition of source adiabatic temperature that takes care of the correction due to inhomogeneous substrate thermal boundary condition. In the case of heat spreading through a substrate with convective surfaces it is also shown that the expression for the total thermal resistance can be decomposed into a base solution and a correction. Thus the effects of the unequal heat sinks are consolidated in an approximate way to an equivalent or effective heat sink, Stheta1 that contributes the correction of Stheta1 to the base resistance of the homogeneous solution where the upper and lower heat sink temperatures are the same.
Type:
text; Dissertation-Reproduction (electronic)
Keywords:
Engineering, Mechanical.
Degree Name:
Ph.D.
Degree Level:
doctoral
Degree Program:
Graduate College; Aerospace and Mechanical Engineering
Degree Grantor:
University of Arizona
Advisor:
Ortega, Alfonso

Full metadata record

DC FieldValue Language
dc.language.isoen_USen_US
dc.titleAnalytical solutions of heat spreading resistance from a heat source on a finite substrate with isothermal or convective surfacesen_US
dc.creatorKabir, Humayun, 1963-en_US
dc.contributor.authorKabir, Humayun, 1963-en_US
dc.date.issued1997en_US
dc.publisherThe University of Arizona.en_US
dc.rightsCopyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author.en_US
dc.description.abstractThe objective of this dissertation is to present the analytical solutions to the heat spreading problems that arise due to a flux specified circular heat source on a finite thickness substrate with isothermal or convective surfaces. The solutions to heat spreading resistance of these problems are obtained for the first time by the exact treatment of the mixed boundary conditions present on the substrate at the heat source side. In the case of heat spreading through a substrate with isothermal surfaces the solution method utilizes the two-dimensional axisymmetric equation of thermal conduction allowing for the convective cooling over source region. In the absence of convection over the source, it is shown that the total thermal resistance is composed of spreading resistance of an otherwise isothermal substrate and a correction due to inhomogeneous substrate thermal boundary condition. The application of the method of superposition elucidates the exact definition of source adiabatic temperature that takes care of the correction due to inhomogeneous substrate thermal boundary condition. In the case of heat spreading through a substrate with convective surfaces it is also shown that the expression for the total thermal resistance can be decomposed into a base solution and a correction. Thus the effects of the unequal heat sinks are consolidated in an approximate way to an equivalent or effective heat sink, Stheta1 that contributes the correction of Stheta1 to the base resistance of the homogeneous solution where the upper and lower heat sink temperatures are the same.en_US
dc.typetexten_US
dc.typeDissertation-Reproduction (electronic)en_US
dc.subjectEngineering, Mechanical.en_US
thesis.degree.namePh.D.en_US
thesis.degree.leveldoctoralen_US
thesis.degree.disciplineGraduate Collegeen_US
thesis.degree.disciplineAerospace and Mechanical Engineeringen_US
thesis.degree.grantorUniversity of Arizonaen_US
dc.contributor.advisorOrtega, Alfonsoen_US
dc.identifier.proquest9738972en_US
dc.identifier.bibrecord.b37476749en_US
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