code_saturne User's Forum

Hello,
I am trying to simulate natural convection in a cylinder with Code-Saturne 2.1.7:
bottom is 30 deg. C
sides and top is 20 deg. C
But I can't see any convection.
I attached case xml file, maybe you can see what is wrong?

Thank you,
Kestutis

Hello,

You seem to have run only 10 iterations. Natural convection is usually quite slow to set in, so you probably need to run a much longer simulation (go by stages).

Especially, when the fluid is initially "at rest", there is no turbulent diffusion, but only molecular diffusion at start, so heat is transferred very slowly if you use a Dirichlet condition.

Regards,

Yvan

Hello,

I see no heat transfer between wall and domain, why?

• I did several simulations using:
  Turbulence: Laminar, LES
  Boundary: Smooth Wall, Rough Wall
  Type: Prescribed Value, Coefficient
  30 iterations, each 0.05s

CS version 3.1
Case file: https://www.dropbox.com/sh/1hyrhqvzpien77c/LZhu88LVcX top right click download -> as zip

Regards and thanks for help
Kestutis