Multi-physics modeling of heat and particle transfer in porous media

The dissertation comprises two main components: underground duct-bank thermal dissipation considering the convection heat transfer in porous media and the filtration mechanisms of bentonite grout in porous media. In the first part, the study challenges traditional underground duct-bank design assumptions and introduces a novel approach to enhance heat dissipation performance. Through comprehensive experimental investigations and analysis, the research demonstrates that convective heat transfer facilitated by highly permeable and saturated porous backfill materials can significantly improve heat dissipation capabilities compared to conventional low-permeability soil installations. The use of saturated high-permeability pea gravel as backfill is shown to increase the effective heat dissipation rate significantly, leading to substantial benefits for underground cable system design and operations. The study also provides numerical simulation that is calibrated with empirical data and develops quantitative relationships that account for convective heat transfer effects in high-permeability porous media, laying the foundation for formulating new design methodologies and heat transfer models. Furthermore, the research challenges long-standing industry practices, introduces a paradigm shift in underground cable system design philosophy, and presents a transformative solution to improve heat dissipation capabilities, system performance, and economic viability. The findings have significant implications for advancing the state of the art in underground power transmission and distribution infrastructure design. In the second part, the research addresses the complex filtration mechanism of bentonite suspensions during permeation grouting in porous media. A numerical model is introduced to capture the two-way interactions between the permeating grout and the porous medium, accounting for changes in rheology, concentration, porosity, and permeability. This model provides new insights into the fundamental understanding of particle transport and retention phenomena during permeation grouting, which is crucial for predicting the success of grouting processes in geo-engineering projects. Additionally, the paper's use of the Shuffled Complex Evolution (SCE) method for inverse modeling to determine optimal filtration parameters and permeability reduction parameters further enhances the significance of the research by providing a robust and efficient approach to locate the global optimal set of parameters. The research significantly advances the understanding of the complex bentonite filtration mechanisms and offers valuable insights for improving the success and predictability of grouting processes in geo-engineering projects.

Name thesis:degree_name

Doctor of Philosophy

Level thesis:degree_level

DOCTORAL

Discipline thesis:degree_discipline

Civil Engineering

Grantor

The University of Texas at Austin

Year dc:date.issued

2024

Author dc:creator

• Ye, Yiwei, Ph. D.

Advisor dc:contributor.advisor

• El Mohtar, Chadi Said

Committee members dc:contributor.committeemember

• Krishna Kumar
• Ellen Rathje

• Underground duct bank
• Porous media
• Particle transfer
• Filtration
• Heat transfer
• Natural convection

Language dc:language.iso

English

Identifier URI

https://doi.org/10.26153/tsw/64246

OAI identifier oai:identifier

oai:repositories.lib.utexas.edu:2152/136944