Description

This project simulates airflow within a building’s double-skin façade (DSF) using ANSYS Fluent. In a DSF, solar-heated air rises due to buoyancy, providing passive heating and aiding ventilation/cooling inside the building.

The 3D geometry (DesignModeler) is a rectangular cavity measuring 0.6 × 3.2 × 5 m, composed of a duct for airflow and a glazed section that absorbs solar heat. Openings include a 0.2 m rectangular inlet at the bottom of the glass wall and a 0.2 m outlet near the top. Meshing (ANSYS Meshing) yields 490,725 elements.

Methodology

The study evaluates buoyancy-driven circulation in the DSF cavity. The glass section is modeled with a volumetric heat generation of 6940 W/m³ to represent solar gain. Building walls are brick and subject to convection to the interior: T = 300 K, h = 23 W/m²·K (free convection).

Supply air enters the façade at 304.55 K and atmospheric pressure. To capture buoyancy, air density follows the ideal gas law, and gravity = 9.81 m/s² is applied.

Conclusion

Post-processing provides 2D/3D pressure, velocity, and temperature contours, plus 2D/3D velocity vectors. The vectors show an upward flow in the cavity, confirming buoyancy-driven ventilation within the double-skin façade.