Lecture 1 - HYDROSTATICS (Pore scale)

Time/Date: Fri June 7 / 13:30 - 16:30 / Room 145 / Building 115

Outline:

  • The standard bundle of capillaries model - advantages and limitations
  • A unitary approach (Augmented Young-Laplace [AYL] equation) to liquid retention considering capillarity and adsorption
  • Solid liquid interactions - the disjoining pressure
  • Analytical representation of curved liquid-vapor interfaces in different geometries
  • AYL in two-dimensional angular pore spaces
  • Simplifications to AYL - new retention functions for angular pore
  • Snap-off mechanisms in 2-D pores
  • Liquid-vapor interfacial area function - importance for gas exchange
 

Lecture 2 - HYDROSTATICS (Sample scale)

Time/Date: Mon June 10 / 13:30 - 16:30 / Room 145 / Building 115

Outline:

  • How to upscale retention function from a single pore to a population of pores?
  • Behavior in three-dimensional pore networks
  • Snap-off mechanisms in 3-D rhombic tubes - fluid entrapment, cavitation
  • Alternative modeling approaches (Mike Sukop):
    • Lattice Boltzmann
    • Fractal porous media
    • Energy minimization
    • Percolation theory and 3-D pore networks
  • Data requirements for model application in 2-D parallel cell model a flowchart for a new framework
  • Examples for water characteristics function - (Excel worksheet)
  • Examples for liquid-vapor interfacial function - (Excel worksheet)
 

Lecture 3 - HYDRODYNAMICS (homogeneous porous media)

Time/Date: Wed June 12 / 13:30 - 16:30 / Room 145 / Building 115

Outline:

  • The standard bundle of capillaries model - advantages and limitations
  • Laminar flow in full angular ducts (analytical expressions for regular shapes)
  • Laminar flow in corners bounded by a liquid-vapor interface (Ransohoff & Radke)
  • Laminar flow in very thin films - effects of modified liquid viscosity
  • A critical assumption - equilibrium interfaces are "forever" (examples)
  • Darcy's law for hydraulic conductivity from average velocities under unit gradient
  • Assembling unsaturated hydraulic conductivity function for a unit cell
  • A population of parallel pathways - upscaling to a 2-D sample scale
  • Examples - highlighting the role of film flow affecting the "tail" of K(m) function - (Excel worksheet)
 

Lecture 4 - HYDRODYNAMICS (fractured porous media)

Time/Date: Fri June 14 / 13:30 - 16:30 / Room 145 / Building 115

Outline:

  • Hydraulic conductivity for a wet rough surface
  • Representation of fractured porous media (FPM) as a dual-continuum
  • Hydraulic conductivity for FPM
  • Applications to two examples of FPM - (Excel worksheet)
  • Extension to macroporous soils - examples
  • Aspects of 3-D networks - tradeoffs between geometrical complexity with simple physics, and simplified geometry with complex physics of flow
  • Critical path analysis - capturing 3-D behavior from univariate pore statistics
 

Lecture 5 - INTERMITTENT FLOWS

Time/Date: Mon June 17 / 13:30 - 16:30 / Room 145 / Building 115

Outline:

  • Finger flow in fractures and soils
  • The importance of gravitational forces - Bond, Capillary and Jeffery numbers
  • Formation of liquid clusters (bridges)
  • Optimal configurations of liquid bridges (for a fixed volume)
  • Force balance equation for a growing suspended bridge
  • Breakup of liquid bridges (internal dripping)
  • Intermittent and chaotic fluxes resulting from simple (and deterministic) dynamics
  • Avalanches in fractures ("rain drops on windshield" model)
  • Resolving fracture internal geometry from flux information?
  • Extension to finger flow in soils - Bond number
 

Lecture 6- HYDRAULIC PROPERTIES OF SWELLING POROUS MEDIA

Time/Date: Wed June 19 / 13:30 - 16:30 / Room 145 / Building 115

Outline:

  • Swelling phenomenon and clay lamellar spacing
  • Interacting DDL and swelling pressure
  • Swelling and the concept of disjoining pressure (DLVO)
  • Modeling clay fabric geometry and other textural elements
  • Physical constraints on volume changes
  • Liquid retention functions (pore scale)
  • Pore scale hydrodynamics – Sat. hydraulic conductivity
  • Outlook for upscaling to sample scale
 

Lecture 7- PHYSICAL PROCESSES AFFECTING MICROBIAL HABITATS AND ACTIVITY IN UNSATURATED POROUS MEDIA

Time/Date: To be arranged if time allows.

Outline:

  • Pore space and liquid configuration – interfacial fragmentation
  • General observations regarding liquid and gaseous diffusion (examples)
  • Formation of microbial communities to cope with changes - the role of EPS in microbial biofilms
  • Properties of biofilm EPS (3-D structure; liquid retention and transport properties; mechanical functions)
  • Consequences on soil structure and wettability.
  • Questions and open issues:
    • Spatial distribution in pore space.
    • Microbial effects on macroscopic fluxes.
    • Quantification of microbial interactions.
 
 
 

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