Double Skin Façade CFD Simulation by ANSYS Fluent Training

Description

The present problem simulates the airflow inside the interior of the double-skin facade of buildings using ANSYS Fluent software. We perform this CFD project and investigate it by CFD analysis.

In double-skin facades, the collected air uses heating received from sunlight and moves upward due to the effect of buoyancy, causing heating and cooling inside the buildings.

The present model is designed in three dimensions using Design Modeler software. The model’s geometry is related to the double skin facade with dimensions of 0.6 m * 3.2 m * 5 m in the shape of a rectangular cube, consisting of a duct section for airflow and a glass section for receiving solar radiation heat.

A rectangular inlet valve (0.2 m) is located at the bottom of the glass wall, and a rectangular outlet valve (0.2 m) is located above the glass wall.

The meshing of the model has been done using ANSYS Meshing software. The element number is 490725.

Facade Methodology

This work aims to investigate the effect of buoyancy on the behavior of heated air inside the interior of a double-skin facade. The interior of this facade consists of a glass part as a source of heat from the sun and a duct-shaped part for airflow.

Therefore, it is assumed that the glass part of the model has a constant amount of heat generation equal to 6940 W/m3.

The walls of the buildings are made of brick and have a thermal boundary condition of Convection; Thus, free convection condition is enabled, and the air temperature inside the buildings is equal to 300 K, and the heat transfer coefficient is equal to 23 W/m2K.

The inlet airflow to this double-skin facade has a temperature of 304.55 K and pressure equal to atmospheric pressure.

Also, to study the buoyancy effect, the air density is defined to change based on ideal gas law, and the gravitational force equal to 9.81 m/s2 is defined in the model.

Facade Conclusion

At the end of the solution process, two-dimensional and three-dimensional contours related to pressure, velocity, and temperature, as well as two-dimensional and three-dimensional velocity vectors, are obtained.

As can be seen from the behavior of velocity vectors, the airflow inside the chamber moves upwards, indicating the buoyancy effect of the ventilation system.