Kishan Konannavar
Ansys Employee
Hello
You want to simulate using a constant value of radiation in the first case?
Meanwhile, you may want to explore the solar load model of fluent: 14.3.11. Solar Load Model (ansys.com)
For the second case maybe you could try using expressions in an appropriate radiation model
14.3.1. Using the Radiation Models (ansys.com)
5.3. Creating and Using Expressions (ansys.com)
Hope it works.
Regards
Kishan