First of all thank you for your patient, I know I have asked so many basic questions; I hope you can guide me as before:
I am simulating a hot object, inside a box; the bot T is fixed and constant, but the air T and the object T can change.
My goal is to simulate and calculate the T and air flow (natural convection), Especially ! while considering the radiation from the hot surface, and back reflection of other surfaces.
I believe, after some time, other surfaces can also act as secondary radiators, and of course reflection of the walls can increase the T of the hot surface as well.
![Image](https://i.postimg.cc/FYPSbvrj/q-1.jpg)
Usually, engineers will simplify the question and only simulate the air, but before that, I need to make sure about the reaction of boundaries.
Noslip
1
![Question :?:](./images/smilies/icon_question.gif)
(I believe it is not needed, since the navier-stoke is not active for the solid body, but better safe to ask than sorry)
Radiation
2
![Question :?:](./images/smilies/icon_question.gif)
3
![Question :?:](./images/smilies/icon_question.gif)
4
![Question :?:](./images/smilies/icon_question.gif)
General Radiation Q
5
![Question :?:](./images/smilies/icon_question.gif)
6
![Question :?:](./images/smilies/icon_question.gif)
or maybe there is a third option....?
Redundancy Q
7
![Question :?:](./images/smilies/icon_question.gif)
7.1 _ nonslip : applying this condition both at the solid boundary and fluid boundary.
7.2 _ emissivity : applying the emissivity value both at the material property and boundary condition after idealized radiation.
7.3 _ temperature : when I have heatflux/constant T from one boundary/surface, entering to another, Do I need to apply it both at my hot object and as an external T in my receiving object ?
Some visualization of my question + some other scenarios are demonstrated with the following pictures:
![Image](https://i.postimg.cc/15LsHXjT/q-2.jpg)
![Image](https://i.postimg.cc/7YTyfDZN/q3.jpg)