Lattice boltzmann modeling of fluid flow to determine the permeability of a karst specimen

Authors

Pedro Felix Alvarez, Florida International University

Document Type

Thesis

Degree

Master of Science (MS)

Major/Program

Geosciences

First Advisor's Name

Michael C. Sukop

First Advisor's Committee Title

Committee Chair

Second Advisor's Name

David Chatfield

Third Advisor's Name

Rene Price

Date of Defense

3-28-2007

Abstract

A limestone sample was scanned using computed tomography (CT) and the hydraulic conductivity of the 3D reconstructed sample was determined using Lattice- Boltzmann methods (LBM) at varying scales. Due to the shape and size of the original sample, it was challenging to obtain a consistent rectilinear test sample. Through visual inspection however, 91 mm and 76 mm samples were digitally cut from the original. The samples had porosities of 58% and 64% and produced hydraulic conductivity values of K= 13.5 m/s and K=34.5 m/s, respectively. Both of these samples were re-sampled to 1/8 and 1/64 of their original size to produce new virtual samples at lower resolutions of 0.542 mm/lu and 1.084 mm/lu, while still representing the same physical dimensions. The hydraulic conductivity tended to increase slightly as the resolution became coarser. In order to determine an REV, the 91 mm sample was also sub-sampled into blocks that were 1/8 and 1/64 the size of the original. The results were consistent with analytical expectations such as those produced by the Kozeny-Carman equation. A definitive REV size was not reached, however, indicating the need for a larger sample. The methods described here demonstrate the ability of LBM to test rock structures and sizes not normally attainable.

Identifier

FI14031608

Recommended Citation

Alvarez, Pedro Felix, "Lattice boltzmann modeling of fluid flow to determine the permeability of a karst specimen" (2007). FIU Electronic Theses and Dissertations. 1270.
https://digitalcommons.fiu.edu/etd/1270