Solar Radiation at Different Hours CFD Simulation by ANSYS Fluent Solar Ray Tracing Model Training

This simulation is about Solar Radiation at Different Hours via ANSYS Fluent software. We perform this CFD project and investigate it by CFD analysis.

Due to the curvature of the earth’s axis around the sun, it receives different intensities and angles of radiation in different seasons of the year. Therefore, more radiation was received in the tropical regions due to the intensity and angle of radiation close to zero.

On the other hand, latitude, longitude, and distance from Greenwich origin indicate a unique place on earth to represent a city. Simultaneous modeling of conduction, convection, and solar radiation can predict surfaces exposed to heat transfer and find critical temperature points.

In this study, the effects of radiation from the sun in an environment where airflow is established are investigated. In addition, the conduction heat transfer was considered in solid objects.

The amount of radiation received was modeled with the geographical characteristics of Baku (The capital of Azerbaijan) at 8 AM and 3 PM on June 21st. The free air velocity was 10 m / s with a temperature of 27 degrees Celsius.

Soil, brick, and wood material specifications were given for land, house, and tree. Finally, by examining the radiation flux, objects' surface temperature, and the average temperature inside the house, radiation heat in the morning and noon was determined.

The geometry of the present model is drawn by Design Modeler software. The model is then meshed by ANSYS Meshing software. The model mesh is unstructured, and 2054294 cells have been created.

CFD Method

In this simulation, the radiation model is used to define the radiation heat transfer; Because the main heat transfer method for thermal analysis in this project is the radiation method. Therefore, the discrete ordinate (DO) model is used to define radiation.

The discrete ordinates model is used for cases where the radiation heat transfer equations are solved for a finite number of discrete solid angles. This model is the most comprehensive radiation model.

It is used for scattering light, semi-transparent environments, glossy surfaces such as mirrors, and wavelength-dependent transitions.

Also, Solar-Ray tracing has been used to define the solar radiation in the computational zone of the model. In this problem, longitude and latitude, time zone, and day and hour radiation are determined. Based on these data, the intensity of solar radiation and the direction of solar radiation is obtained.

Solar Radiation at Different Hours Conclusion

After simulation, the contours of temperature and radiation heat flux are obtained. Also, the maximum temperature in the computational zone is obtained for two study cases (8 and 15 o’clock).

It was observed that according to the amount of radiation received by the domain at different hours, as gets closer to 15 o’clock with increasing radiation intensity and angle compared to 8 o’clock, a difference of 6 degrees was obtained from the maximum temperature.

The maximum temperature was about 312 K at 8 AM and 318 K at 3 PM. Due to the thermally safe zones in terms of temperature between the houses and the shade of the tree, the amount of radiation flux received in these areas for two different cases was in the range of 50 to 70 W / m2, which indicates that with increasing heat received from the sun, in shady areas will not be felt much.

This CFD Project is the 6th episode of the Radiation Model Training Course.