Air transfer analysis
AIR/W is a powerful finite element software product for modeling air transfer in mine waste and other porous media. AIR/W can be used to model a range of scenarios, from simple single phase air transfer problems to complex coupled air-water systems.
Add AIR3D to analyze 3D air transfer using the same comprehensive set of material models and boundary conditions.
The true power of AIR/W and AIR3D is unlocked when it is coupled with TEMP/W to model forced-convection heat flow and density-dependent air flow. This type of analysis is important for studying mine closure, acid rock drainage, or gas transfer.
Density Dependent Air Flow
AIR/W can be integrated with TEMP/W to model air transfer via free convection. Density-driven air transfer is often a dominant mechanism in systems subjected to seasonal ground temperature variations. Integration of AIR3D and TEMP3D is also available.
Estimate Material Properties
The air conductivity function can be generated based on the dry-soil air conductivity, a user-selected volumetric water content function, and basic soil properties, such as soil classification or grain size distribution.
Forced-Convection Heat Transfer
Combine AIR/W or AIR3D with TEMP/W or TEMP3D to model forced-convection heat transfer. This process often governs the thermal regime in coarse-grain materials such as waste rock piles, rip-rap, and layered embankments.
Single or Dual Phase Flow
Air transfer analyses can be conducted using a single phase material model that only considers pressure and gravity-driven air flow. Alternatively, a dual phase material model can be used by coupling air flow and water transfer.
AIR/W and AIR3D can model almost any problem involving air transfer through porous media
Goering (2000) investigated passive cooling within an embankment constructed of unconventional and highly porous material as a means of preserving permafrost. The objective of this example is to simulate similar convective cell behavior in AIR/W and TEMP/W as observed by Goering.
Verification – Heated Closed System
The change in pressure of a constant volume of dry air subject to an increase in temperature is simulated in this verification example. The temperature increase is simulated by TEMP/W while the air pressure response is simulated by AIR/W.
AIR/W’s intuitive modeling workflow
- Create problem workspace and analysis properties
- Draw or import domain regions from a CAD program
- Define material properties, pore-air pressure & air flow
- Define boundary conditions
- Draw mesh properties
- Solve your analyses
- Display computed pore-air pressure
- View results, generate plots and reports