### AIR/W 空氣流量分析軟體

AIR/W is a finite element software product for analyzing groundwater-air interaction problems within porous materials such as soil and rock. Its comprehensive formulation allows you to consider analyses ranging from simple, saturated steady-state problems to sophisticated, saturated-unsaturated time-dependent problems. You can apply AIR/W to the analysis and design of geotechnical, civil, hydrogeological, and mining engineering projects.

AIR/W can be applied to both saturated and unsaturated zones, a feature that greatly broadens the range of problems that can be analyzed. In addition to traditional steady-state water flow assumptions where the air contents are fixed, the saturated/unsaturated formulation of AIR/W makes it possible to analyze air flow and seepage as a function of time and to consider such processes as changing air and water contents. When linked with TEMP/W, it can account for air and water flow in freezing and thawing soils where the air density changes due to temperature changes.

**Defining a Seepage/Air flow Model**

The unique CAD-like technology in AIR/W allows you to generate your finite element mesh by drawing regions on the screen. You can then interactively apply boundary conditions and specify material properties. You can even estimate the material property functions from easily measured parameters like grain-size, saturated conductivity, saturated water content, and the air-entry value. If you make a mistake, you can correct it using the Undo command.

**Viewing the Analysis Results**

Once you have solved your seepage problem, AIR/W offers many tools for viewing results. Generate contours or x-y plots of any computed parameter, such as head, pressures, matric suction, gradients, velocities, and conductivities. Air or water velocity vectors show flow direction and rate. Transient conditions can be shown as the changing water table position over time. Interactively query computed values by clicking on any node, Gauss region, or flux section. Then export results into other applications, such as Microsoft Excel or Word, for further analysis or to prepare presentations.

AIR/W can model almost any groundwater problem, including:

- Soil vapor extraction systems
- Air pressure in tunnels for support and water inflow control
- Air pressure response ahead of water infiltration fronts
- Thermal / density dependent air flow that contributes to convective heat transfer in freezing / thawing soils (when coupled with TEMP/W)
- The true matric suction (Ua-Uw) phenomenon