Air flow analysis
AIR/W simulates groundwater-air interaction problems within porous materials such as soil and rock. Its enables analyses ranging from simple single phase air-transfer analyses to complex coupled air-water systems.
The true power of AIR/W 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.

Key Features
Density Dependent Air Flow
AIR/W can be integrated with TEMP/W to model air transfer via free convection. Density-driven air transfer is generally the dominant mechanism present in systems subjected to climatic influences such as seasonal ground temperature variations.
Estimate Material Properties
The air conductivity function can be generated based on the dry-soil air conductivity and a user-selected volumetric water content function. The estimation process requires only fundamental information for the soil, namely, the dry-soil air conductivity.  
Forced-Convection Heat Transfer
Combine AIR/W with TEMP/W to model forced-convection heat transfer. This process often governs the thermal regime in coarse-grain materials such as waste rock piles, rip-rap on the face of hydraulic structures and embankments with fine-coarse layering.
Single / Dual Phase Flow
Air transfer analysis can be conducted using a single phase material model where only pressure and gravity-driven air flow is considered. A dual phase material model may also be used by coupling air flow to a water transfer analysis.