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Fixed Temperature Boundary Condition

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Hello, I'm new to COMSOL and am trying to run a non-isothermal flow problem where I have basically a rectangular solid object immersed in a volume of air flowing across the object. I placed a fixed temperature boundary condition on one of the sides of the rectangle, a temperature and velocity boundary condition on the inlet and a pressure boundary condition on the outlet. What I'm trying to accomplish is to determine the heat loss from the object to the air (without radiation for the time being). After I run the scenario, I plot the temperature and to my surprise the temperature on the wall that I placed the fixed boundary condition on is somehow lower than the fixed value I applied. What have I done wrong, or is there something else I need to do to the model?

Thanks

1 Reply Last Post May 22, 2012, 11:47 a.m. EDT
Ivar KJELBERG COMSOL Multiphysics(r) fan, retired, former "Senior Expert" at CSEM SA (CH)

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Posted: 1 decade ago May 22, 2012, 11:47 a.m. EDT
Hi

how much is "somewhat lower" in % or other values. nad how do you define the value ? an average ...

If you are running a time series its easy to get numerical errors from too coarse mesh and to short time steps relative to the material properties

--
Good luck
Ivar
Hi how much is "somewhat lower" in % or other values. nad how do you define the value ? an average ... If you are running a time series its easy to get numerical errors from too coarse mesh and to short time steps relative to the material properties -- Good luck Ivar

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