Wall boundary condition (a very simple question)

safa_c · August 6, 2010, 13:37

Dear all,

I am a beginner in FLUENT and my apology for this simple question. I would appreciate your explanation.

I am using FLUENT in order to simulate natural convection in a room. All my boundary conditions are specified as wall. In pre-processing I assigned different uniform temperatures to all wall surfaces. But after the simulation is finished, when I check the surface temperature of the walls, I do not have uniform temperatures at the walls that I assigned.

Shouldn't the wall boundary conditions remain fixed and unchanged during the CFD iterations?

Why do the uniform wall surface temperature before the simulation change to non-uniform wall surface temperature after the simulation?

Thanks a lot for your explanation,
Safa van Jansen

xrs333 · August 15, 2010, 06:05

Hello, Safa,
two reasons: one is because of different temperature of the walls, the temperature at the intersect line of two walls is blend of temperatures on them. The other is that you displayed cell value for the temperature, which is actually the value in the cell adjacent to the wall. To display the wall temperature, use Wall Temperature(Outer Surface) under Contours of pulldown list.

August 6, 2010, 13:37	Wall boundary condition (a very simple question)	#1
safa_c New Member Safa van Jansen Join Date: Aug 2010 Posts: 2 Rep Power: 0	Dear all, I am a beginner in FLUENT and my apology for this simple question. I would appreciate your explanation. I am using FLUENT in order to simulate natural convection in a room. All my boundary conditions are specified as wall. In pre-processing I assigned different uniform temperatures to all wall surfaces. But after the simulation is finished, when I check the surface temperature of the walls, I do not have uniform temperatures at the walls that I assigned. Shouldn't the wall boundary conditions remain fixed and unchanged during the CFD iterations? Why do the uniform wall surface temperature before the simulation change to non-uniform wall surface temperature after the simulation? Thanks a lot for your explanation, Safa van Jansen

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August 15, 2010, 06:05		#2
xrs333 Senior Member xrs333 Join Date: Aug 2010 Posts: 125 Rep Power: 17	Hello, Safa, two reasons: one is because of different temperature of the walls, the temperature at the intersect line of two walls is blend of temperatures on them. The other is that you displayed cell value for the temperature, which is actually the value in the cell adjacent to the wall. To display the wall temperature, use Wall Temperature(Outer Surface) under Contours of pulldown list.