Date of Award

Fall 12-20-2020

Level of Access Assigned by Author

Open-Access Thesis

Degree Name

Master of Science (MS)

Department

Mechanical Engineering

Advisor

Zhihe Jin

Second Committee Member

Richard Kimball

Third Committee Member

Yingchao Yang

Abstract

Flows of Newtonian and non-Newtonian fluids in porous media are of considerable interest in several diverse areas, including petroleum engineering, chemical engineering, and composite materials manufacturing. In the first part of this thesis, one-dimensional linear and radial isothermal infiltration models for a non-Newtonian fluid flow in a porous solid preform are presented. The objective is to investigate the effects of the flow behavior index, preform porosity and the inlet boundary condition (which is either a known applied pressure or a fluid flux factor) on the infiltration front, pore pressure distribution, and fluid content variation. In the second part of the thesis, a one-dimensional linear non-isothermal infiltration model for a Newtonian fluid is presented. The goal is to investigate the effects of convection heat transfer and the applied boundary conditions, which are the applied pressure and the inlet temperature, on the infiltration front, pore pressure distribution, temperature variation, and fluid content variation. For all types of infiltrations studied in this thesis, the governing equations for the three-dimensional (3D) infiltration are first presented. The 3D equations are then reduced to those for one-dimensional (1D) flow. After that, self-similarity solutions are derived for the various types of 1D flows. Finally, numerical results are presented and discussed for a ceramic solid preform infiltrated by a melted polymer liquid. The theoretical models and numerical results show that 1. For 1-D linear isothermal infiltration of a non-Newtonian fluid, the dimensional infiltration front varies with time according to 𝑑𝑛𝑛+1, where 𝑛 is the flow behavior index. The dimensionless infiltration front increases with an increase in the flow behavior index 𝑛, and decreases with an increase in the porosity of the porous solid. The pore pressure varies almost linearly from the inlet to the infiltration front. The fluid content variation becomes negative when the non-dimensional distance reaches about 55% of the infiltration front. 2. For 1-D radial isothermal infiltration of a non-Newtonian fluid, the dimensional infiltration front varies with time according to 𝑑𝑛𝑛+1. The dimensionless infiltration front increases with an increase in the flow behavior index 𝑛, and decreases with an increase in the porosity of the porous solid. The pore pressure varies non-linearly from the inlet and reaches zero at the infiltration front. 3. The fluid travels farther in the linear infiltration than in the radial infiltration. 4. For 1-D linear non-isothermal infiltration of a Newtonian fluid, the dimensional infiltration front varies with time according to 𝑑12. It appears that the convection has a negligible effect on the infiltration front and the pore pressure distribution. The infiltration front increases with a decrease in the porosity of the porous solid. The pore pressure varies almost linearly from the inlet to the infiltration front, where it reaches zero. With an applied temperature drop at the inlet, the temperature variation increases with increasing distance from the inlet and reaches zero at a distance farther than the infiltration front, not at the infiltration front.

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