Solid initial at 227 and fluid initial at 20. Body has a radiating boundary at 227. Inlet has 0 degree fluid. The initial condition looks as expected.
After the flow starts the 0 degree fluid is entering the inlet. However a cold region grows over the solid, foes to -200 degrees. Heat is seen radiating from the solid on the right side.
I did not expect this cold region to form, should it be expected?Cold flow across a hot solid
-
- Posts: 2428
- Joined: 25 Jan 2019, 01:28
- Antispam: Yes
Re: Cold flow across a hot solid
Hi,
AFAIK if radiation is involved all temperatures have to be in K.
HTH,
Matthias
AFAIK if radiation is involved all temperatures have to be in K.
HTH,
Matthias
-
- Posts: 2428
- Joined: 25 Jan 2019, 01:28
- Antispam: Yes
Re: Cold flow across a hot solid
Converted the temperatures to Kelvin, same result, there is a cooling area above the hot solid, prior to the cold flow reaching it.
Re: Cold flow across a hot solid
I have met the same troubles. It is numerical instabilities near high temperature gradient.
You can look here:
viewtopic.php?f=3&t=4164&p=14705#p14705
Peter gave me some tips. In fact, only mesh refining near the walls was resultative.
You can look here:
viewtopic.php?f=3&t=4164&p=14705#p14705
Peter gave me some tips. In fact, only mesh refining near the walls was resultative.
Re: Cold flow across a hot solid
PS: I do not tried to play with Initial guess.
-
- Posts: 2428
- Joined: 25 Jan 2019, 01:28
- Antispam: Yes
Re: Cold flow across a hot solid
Thanks, mesh refinement was my next step, and it resolved the problem.
Kevin
Kevin