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-   -   Perfect adiabatic boundary condition (https://www.cfd-online.com/Forums/openfoam-pre-processing/227856-perfect-adiabatic-boundary-condition.html)

Hossein_s June 12, 2020 06:26

Perfect adiabatic boundary condition
 
Hi openFoamers,
Does anyone have any idea how a perfect adiabatic boundary condition (zero net flux of convection and radiation) can be implemented in openFOAM? I am using chtMultiregionSimpleFOAM solver.

Nabeel Abed June 15, 2020 15:12

Hi Hossein
For convection part, you have to set in 0/Folder, solid part:

{

type fixedGradient;
gradient uniform 0;

}


In constant folder for radiation part, fluid region/ radiationProperties file

radiation off;

radiationModel none;

Hossein_s June 15, 2020 16:20

Hi Nabeel,
Thank you for your answer.
The fixedGradient b.c doesn't do what I want (zero net flux), since we have the contribution of radiation! Basically we need the radiation, so it can not be also turned off!
I implemented a boundary condition using the heat balance at the boundary and defining an adiabatic surface temperature based on analytical solution!

Thank you by the way :)

Hossein_s June 18, 2020 06:03

Simpler way!
Using externalWallHeatFluxTemperature, mode -> power or flux, q or Q -> 0! This way the heat balance equation will be set to zero.

Nabeel Abed June 19, 2020 16:26

Quote:

Originally Posted by Hossein_s (Post 774990)
Simpler way!
Using externalWallHeatFluxTemperature, mode -> power or flux, q or Q -> 0! This way the heat balance equation will be set to zero.

Hi Hossein
I never use it.. It's good chance to have a look... Thanks for the sharing

Best Regards
Nabeel


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