heat transfer convection boundary condition

JohnJohn8 · August 8, 2016, 05:06

Dear all,

I am new to OpenFoam and I want to simulate a block which is cooled by convection at a surface and I am interested in the heat conduction in the block. After research, I found the boundary type: convectiveHeatTransfer, after inputting in as patch type and try to run laplacianFoam I got an error. This error stated that the patch type was unknown. After looking into the source code I saw that the patch type is included in the source code, but only in turbulence sections. Is this patchtype on applicable to turbulent flow settings?

Thanks in advance.

Kind regards

anishtain4 · August 8, 2016, 11:39

As you can see from the patch it's meant for the compressible RAS simulation were it provides the h.
For your case it is q=ha(Tb-Tf), q=kaDT/Dn => kDT/Dn=h(Tb-Tf)
This is a mixed boundary condition. You need to know h.

JohnJohn8 · August 9, 2016, 06:35

Dear Mahdi,

Thanks for your response.

How exactly do I have to apply this boundary?
Because there is only the thermal diffusivity in the constant folder, how could I specify all the constants?

Thanks in advance.

Kind regards.

zfaraday · August 11, 2016, 06:00

Hi John,

You can check out my web site where I talk about what you need to learn, I think you may find it useful. Besides that, you can also find a further explanation on what Mahdi says in this document, also located in my web.

Hope it helps,

Alex

anishtain4 · August 11, 2016, 11:48

I understand there would be a duplicate of thermal diffusivity, both in constant folder and your boundary condition. But usually this is not that big of a hassle to need to develop your own boundary condition for it. Specially if don't have much experience in OF programming.

August 8, 2016, 05:06	heat transfer convection boundary condition	#1
JohnJohn8 New Member Join Date: Jul 2016 Posts: 13 Rep Power: 10	Dear all, I am new to OpenFoam and I want to simulate a block which is cooled by convection at a surface and I am interested in the heat conduction in the block. After research, I found the boundary type: convectiveHeatTransfer, after inputting in as patch type and try to run laplacianFoam I got an error. This error stated that the patch type was unknown. After looking into the source code I saw that the patch type is included in the source code, but only in turbulence sections. Is this patchtype on applicable to turbulent flow settings? Thanks in advance. Kind regards Last edited by JohnJohn8; August 8, 2016 at 06:15. Reason: background of problem

August 11, 2016, 06:00		#4
zfaraday Senior Member Alex Join Date: Oct 2013 Posts: 337 Rep Power: 22	Hi John, You can check out my web site where I talk about what you need to learn, I think you may find it useful. Besides that, you can also find a further explanation on what Mahdi says in this document, also located in my web. Hope it helps, Alex __________________ Web site where I present my Master's Thesis: foamingtime.wordpress.com The case I talk about in this site was solved with chtMultiRegionSimpleFoam solver and involves radiation. Some basic tutorials are also resolved step by step in the web. If you are interested in these matters, you are invited to come in!

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August 8, 2016, 11:39		#2
anishtain4 Senior Member Mahdi Hosseinali Join Date: Apr 2009 Location: NB, Canada Posts: 273 Rep Power: 18	As you can see from the patch it's meant for the compressible RAS simulation were it provides the h. For your case it is q=ha(Tb-Tf), q=kaDT/Dn => kDT/Dn=h(Tb-Tf) This is a mixed boundary condition. You need to know h.

August 9, 2016, 06:35		#3
JohnJohn8 New Member Join Date: Jul 2016 Posts: 13 Rep Power: 10	Dear Mahdi, Thanks for your response. How exactly do I have to apply this boundary? Because there is only the thermal diffusivity in the constant folder, how could I specify all the constants? Thanks in advance. Kind regards.

August 11, 2016, 11:48		#5
anishtain4 Senior Member Mahdi Hosseinali Join Date: Apr 2009 Location: NB, Canada Posts: 273 Rep Power: 18	I understand there would be a duplicate of thermal diffusivity, both in constant folder and your boundary condition. But usually this is not that big of a hassle to need to develop your own boundary condition for it. Specially if don't have much experience in OF programming.