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Dear all,

I am having trouble with modeling natural convection for a while. I have started with a very simple case of having a hot plate at 150 degC surrounded by room temperature air and want to check the velocity and temperature profile n the air and validate it with experimental results.

I set up a hot plate on a desk in our lab. I set the temperature of the plate to be 150 degC and the room temperature was 22.5 degC . the hot plate surface was a square of 14*14 cm. I modeled the quarter of the process due to symmetry.

I used a small air box on the surrounding (80*80*80 cm) yet much bigger than the size of the plate.

after I left the hot plate for a while assuming to reach a steady-state condition I used the thermocouple to measure temperature in its surrounding. I found out that when I got to 30 cm above the hot plate's center air temperature reduces close to room temperature. but unfortunately the model predicts temperature at that location to be 50 degC !

I think somehow the area right above the plate does not getting cooled enough by air motion. maybe there is problem in air movement in that area close to the plate.

I used different combinations of inlet/outlet/open boundary conditions on the bottom face close to the plate and turning plate faces to wall (slip) instead of wall (no slip) to facilitate the air movement but I could not get any better result!

Maybe I should also apply some specific meshing in the domain above the plate such as boundary layer condition!!?

I appreciate if you could take a quick look and kindly give me suggestion for the source causing this problem.

thanks in advance for you time,

Regards,

Mohammad