Solar Radiation effect on a House CFD Simulation

Description

Solar Radiation on House CFD Simulation, ANSYS Fluent Tutorial

Description

The different times of the day, radiation, convection, and conduction affect the temperature of the ground, while the wind’s direction can change. In this project, a gable house in the rectangular-shaped domain is modeled, and the radiation of sunshine on it is simulated while the wind is blowing into the domain from one side.

The inside air is affected by the temperature of the walls and roof and moves due to the convection between them.

Also, pixelation is used in this problem which is advised for simulations with symmetry, periodic, or semi-transparent boundaries and will produce acceptable results. Raising the pixelation requires less computing work than increasing the divisions, which requires more work. However, you should be advised that raising the pixelation raises the calculation cost.

The geometry of the solution is a 3D rectangular domain modeled by ANSYS Design Modeler with 24m, 11.6m, and 19m in X, Y, and Z directions, respectively. ANSYS Meshing software is used for generating meshes of the solution. The elements are all unstructured, and the number of them is 696,480.

This CFD project is the 3rd episode of the ANSYS Fluent General Training Course.

Methodology: Solar Radiation on House

The pressure-based solver is employed due to the incompressibility of the air. It needs to be mentioned that Natural Convection is dominant in this problem. Thus, the gravitational effects shouldn’t be denied. The Also Discrete Ordinates (DO) model for simulating Solar Radiation is used.

Two simulations are carried out for the current problem with the Theta and Phi Pixels of 1 and 2. Eventually, the difference in the results is investigated.

Conclusion

At the end of the solution process, two-dimensional contours, contour lines, pressure, streamlines, and vectors related to the airflow are obtained.

As can be seen in the contours, the house’s roof (the side exposed to the radiation) gets warm by solar radiation, and the air inside the house starts to move due to the buoyancy effect. Also, a wake at the right side of the house is formed, making the flow circulate.

The shadow behind the house is visible due to its lower temperature in relation to the parts exposed to sunlight.

Finally, the temperature in the middle line of the house has a trend like the following plot, increasing as it gets close to the ceiling. The red plot is the plot of the Theta and Phi Pixels of 1 and the black one is for the Theta and Phi Pixels of 2 which provides a more accurate result.