Surface heat diffusion

GabiO · January 13, 2015, 09:15

Hi everybody

I'm working with bouyanSimpleFoam and I'm trying to setup an analog to Fluent's shell conduction. It is a zero thickness surface that allows for heat difussion on hot boundaries in order to avoid unrealistically hot spots.

I've tried to do it using 3D thermal baffles but, I don´t find the way to use them on the domain boundaries.

I'd like to know if there is anyother way to implement this kind of feature, or if it's posible to somehow use baffles adjacent to boundaries.

Has anybody encountered this kind of situation? Any ideas?

Thanks for your help

aminem · June 26, 2015, 05:34

Hi

I have the same problem.

Do you have found a solution?

Thanks

GabiO · July 3, 2015, 04:10

Yes, I did find it.

The problem lies in the specifed patch type of the shell created for the thermalBaffle Boundary condition.
You may have seen that the region created to solve the heat diffusion has 3 patches, two of which (top and bottom) are of type mappedWall. This means that they are related face by face to another patch. 3D thermal baffles, as defined in the standard library, need therefore two patches to connect them to, master and slave, and neither of them can be an empty patch.

There is a way to work around this. Make a copy of the thermalBaffle source code, rename it as externalThermalBaffle or something like that. Find the line where it states that bottom is a mappedWall and change it for a regular wall. Compile it and you are good to go. This will also allow you to impose temperature or heat conditions on the bottom patch beacuse it will no longer be type mapped, it will act as the external wall of your mesh.

Hope that this helped.

January 13, 2015, 09:15	Surface heat diffusion	#1
GabiO New Member Gabriel Ovejero Join Date: Aug 2014 Posts: 2 Rep Power: 0	Hi everybody I'm working with bouyanSimpleFoam and I'm trying to setup an analog to Fluent's shell conduction. It is a zero thickness surface that allows for heat difussion on hot boundaries in order to avoid unrealistically hot spots. I've tried to do it using 3D thermal baffles but, I don´t find the way to use them on the domain boundaries. I'd like to know if there is anyother way to implement this kind of feature, or if it's posible to somehow use baffles adjacent to boundaries. Has anybody encountered this kind of situation? Any ideas? Thanks for your help

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June 26, 2015, 05:34		#2
aminem Member amine Join Date: Jan 2014 Location: FRANCE Posts: 84 Rep Power: 12	Hi I have the same problem. Do you have found a solution? Thanks

July 3, 2015, 04:10		#3
GabiO New Member Gabriel Ovejero Join Date: Aug 2014 Posts: 2 Rep Power: 0	Yes, I did find it. The problem lies in the specifed patch type of the shell created for the thermalBaffle Boundary condition. You may have seen that the region created to solve the heat diffusion has 3 patches, two of which (top and bottom) are of type mappedWall. This means that they are related face by face to another patch. 3D thermal baffles, as defined in the standard library, need therefore two patches to connect them to, master and slave, and neither of them can be an empty patch. There is a way to work around this. Make a copy of the thermalBaffle source code, rename it as externalThermalBaffle or something like that. Find the line where it states that bottom is a mappedWall and change it for a regular wall. Compile it and you are good to go. This will also allow you to impose temperature or heat conditions on the bottom patch beacuse it will no longer be type mapped, it will act as the external wall of your mesh. Hope that this helped.