Does someone have experiences in smoke and fire simulation in buildings? How do I provide a source of smoke or fire? Which radiation model should I select? Does someone have examples?

Frank, V3.6 Flair, has a fire source object from which you can set the heat source (obviously descretised over time) and smoke output. When you are in the menu, if you click on the ? at the top right corner of the screen and then point it at the bottons and click, you will get help on what each button is trying to set.

Try NIST's fire dynamic simulator found under 'software' in the web site

fire.nist.gov