Last Updated July 17, 2017

Formulation

Soil Properties

The hydraulic conductivity of the soil is a function of the negative pore-water pressure in the unsaturated regions. The rate of change in water content is dependent on the pore-water pressure during transient processes. Hydraulic conductivity can be defined as anisotropic in two orthogonal directions.

Iterative Process

The nonlinear nature of the finite element equations is handled using an efficient radial search iterative scheme. Graphing tools are available during run-time to help you judge if convergence has been achieved. This has proved to be extremely useful in solving highly nonlinear flow systems.

Flux Quantities

AIR/W computes the total flux across single or multiple lines drawn through the mesh.

Features

  • Analysis types include steady-state confined and unconfined flow, transient flow, 2-D flow in a cross-section or in plan view, and 3D axisymmetric flow.
  • Boundary condition types include total head, pressure head, or flux specified as a constant or a function of time; pressure head; transient flux as a function of computed head; review and adjustment of seepage face conditions.
  • Volumetric water content and conductivity functions can be estimated from basic parameters and grain-size functions.
  • Adaptive time stepping to ensure the use of optimal time steps in transient analyses with sudden changes in boundary conditions.
  • Flow path deliniation.
  • And many more!

Integration with Other Applications

Use AIR/W data in TEMP/W

AIR/W and SEEP/W integrate with TEMP/W so that you can model convective heat transfer due to moving air and water. Conversely, you can have the thermal solution affect the air densities and pressures in AIR/W so that the air will flow based on thermal processes alone. AIR/W passes air content and mass flow vectors to TEMP/W and it returns the new temperature profile to AIR/W. All of this happens automatically based on your analysis type definition.

Engineering Methodology Book

The included AIR/W engineering methodology book discusses the whys and hows of modeling, as well as the theory and formulations behind the AIR/W product. Air Flow Modeling with AIR/W is a full-length book about proper modeling techniques: how to think before, during and after setting up and solving a model. The book includes chapters devoted to:
  • Material Models and Properties
  • Boundary Conditions
  • Analysis Types
  • Functions in GeoStudio
  • Numerical Issues
  • Visualization of Results
  • Modeling Tips and Tricks
  • Illustrative Examples
  • Theory