Date of Award:

8-2012

Document Type:

Thesis

Degree Name:

Master of Science (MS)

Department:

Mechanical and Aerospace Engineering

Committee Chair(s)

Heng Ban

Committee

Heng Ban

Committee

Byard Wood

Committee

Leijun Li

Abstract

Planetary heat flow is of great interests to planetary scientists, which can be used to determine the history and current status of pianetary bodies. Thermal conductivities of planetary bodies are generally measured using long needle-like probes inserted into planet's surface, which measure the horizontal effective thermal conductivity (parallel to the planetary surface). The vertical effective thermal conductivity (perpendicular to the planetary surface), used for heat flow calculation, is assumed to be the same as the horizontal effective thermal conductivity. However, ETC of particle beds is known to be an anisotropic property under low compressive pressures.

The objective of this study was to first determine the effect of compressive loads, gas pressures, and particle Young's modulus on the ETC of particle beds with mono-dispersed, smooth particles. Secondly, we developed a resistance network heat transfer model to predict ETC of particle beds under low and high compressive pressures with variations in particle sizes, species, and gas pressures. A finite element model was developed in COMSOL Multiphysics to understand the heat transfer mechanism coupled with mechanical deformation of two half contacting particles and to predict the lower limit of ETC of particle beds under compressive pressures. Thirdly, we modified the developed theoretical model to predict both vertical and horizontal ETCs of particle beds under a wide range of compressive pressures with varying gas pressures.

Checksum

b6093fd5d4b2d1777cb33df310ea0b9f

Comments

This work made publicly available electronically on July 30, 2012.

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