Temperature depending on x,y as boundary condition in Steady-state Thermal simulation

FluidCFD · November 29, 2012, 11:18

Hi,

I'd like to add a varying temperature distribution depending on the x and y direction as a boundary condition in a steady-state thermal simulation. When I add "Temperature" to the "Steady-State Thermal" folder in the "Setup" step I can only make it dependent from x or y, but not from both. Can anybody tell me whether it is possible to add a 2D temperature distribution? It should be something like T1-x^2-y^2.

Best regards

cdegroot · November 29, 2012, 11:47

Yes using CEL this is possible.

brunoc · November 29, 2012, 12:32

Quote:

Originally Posted by FluidCFD

Hi,

I'd like to add a varying temperature distribution depending on the x and y direction as a boundary condition in a steady-state thermal simulation. When I add "Temperature" to the "Steady-State Thermal" folder in the "Setup" step I can only make it dependent from x or y, but not from both. Can anybody tell me whether it is possible to add a 2D temperature distribution? It should be something like T1-x^2-y^2.

Best regards

Seems like you're creating your model in Mechanical. This is the forum for CFX. You can do that simulation in CFX using a CEL Expression, as Chris mentioned, and it is quite straightforward.

FluidCFD · December 3, 2012, 06:27

Hi,

thanks to you both. I first tried to do it in CFX and with the help of CEL, then had some other problems and thought, Steady-state Thermal is designed to do exactly what I want to do. Apparently, it is easier to implement in CFX than in Thermal analysis. I got it running now.

Another question: When I want to know the heat flux at an arbitrary plane, is the one displayed normal to that plane?

Best regards

cdegroot · December 3, 2012, 10:38

Glad you got it running. I'm not sure I understand your current question. If you define a plane, the heat flux reported will be the heat flux through that plane.

FluidCFD · December 3, 2012, 11:12

Yeah, that was my question. Can you also tell me what the difference between heat flux and wall heat flux is, as the heat flux is often "not defined" and I don't understand why.

brunoc · December 3, 2012, 12:01

Heat fluxes come from the solver, they're not calculated by CFD-Post, and I think the results file don't include that field. You can calculate it yourself, though. Just create one variable that calculates the temperature gradient, and another one that does the rest of the calculation (heat flux by conduction, advection, etc).

Cheers

November 29, 2012, 11:18	Temperature depending on x,y as boundary condition in Steady-state Thermal simulation	#1
FluidCFD Member Deutschland Join Date: Nov 2012 Posts: 31 Rep Power: 14	Hi, I'd like to add a varying temperature distribution depending on the x and y direction as a boundary condition in a steady-state thermal simulation. When I add "Temperature" to the "Steady-State Thermal" folder in the "Setup" step I can only make it dependent from x or y, but not from both. Can anybody tell me whether it is possible to add a 2D temperature distribution? It should be something like T1-x^2-y^2. Best regards

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November 29, 2012, 11:47		#2
cdegroot Senior Member Chris DeGroot Join Date: Nov 2011 Location: Canada Posts: 414 Rep Power: 18	Yes using CEL this is possible.

December 3, 2012, 06:27		#4
FluidCFD Member Deutschland Join Date: Nov 2012 Posts: 31 Rep Power: 14	Hi, thanks to you both. I first tried to do it in CFX and with the help of CEL, then had some other problems and thought, Steady-state Thermal is designed to do exactly what I want to do. Apparently, it is easier to implement in CFX than in Thermal analysis. I got it running now. Another question: When I want to know the heat flux at an arbitrary plane, is the one displayed normal to that plane? Best regards

December 3, 2012, 10:38		#5
cdegroot Senior Member Chris DeGroot Join Date: Nov 2011 Location: Canada Posts: 414 Rep Power: 18	Glad you got it running. I'm not sure I understand your current question. If you define a plane, the heat flux reported will be the heat flux through that plane.

December 3, 2012, 11:12		#6
FluidCFD Member Deutschland Join Date: Nov 2012 Posts: 31 Rep Power: 14	Yeah, that was my question. Can you also tell me what the difference between heat flux and wall heat flux is, as the heat flux is often "not defined" and I don't understand why.

December 3, 2012, 12:01		#7
brunoc Senior Member Bruno Join Date: Mar 2009 Location: Brazil Posts: 277 Rep Power: 21	Heat fluxes come from the solver, they're not calculated by CFD-Post, and I think the results file don't include that field. You can calculate it yourself, though. Just create one variable that calculates the temperature gradient, and another one that does the rest of the calculation (heat flux by conduction, advection, etc). Cheers