Convection coef below zero

crinoid · April 5, 2019, 03:01

Hi
I am modeling the heat transfer through a fin and onto the air. I have the solid and the fluid domains.
In the tip of the fin, the heat transfer coef has the expected value, but it is below zero. Its temperature is, noneless, greater than the air temp around it and greater than the reference temp.
I don't know where's the problem

Thanks in advance!

LuckyTran · April 5, 2019, 11:00

Are you sure....? What does the heat flux look like?

crinoid · April 5, 2019, 13:54

Hi, LuckyTran
I attach you the heat flux contours and some other images that may be helpful for understanding my problem.

[The images are in the next reply, I don't know how to remove this one]

crinoid · April 5, 2019, 13:58

Hi, LuckyTran
I attach you the heat flux contours and some other images that may be helpful for understanding my problem.

LuckyTran · April 8, 2019, 13:59

Your temperature contour on the tip makes no sense. Check your setup.

Boundary conditions? Is it coupled for the tip or other? It looks like it's not coupled.

April 5, 2019, 03:01	Convection coef below zero	#1
crinoid New Member crinoid Join Date: Jan 2019 Posts: 21 Rep Power: 7	Hi I am modeling the heat transfer through a fin and onto the air. I have the solid and the fluid domains. In the tip of the fin, the heat transfer coef has the expected value, but it is below zero. Its temperature is, noneless, greater than the air temp around it and greater than the reference temp. I don't know where's the problem Thanks in advance!

April 5, 2019, 13:54		#3
crinoid New Member crinoid Join Date: Jan 2019 Posts: 21 Rep Power: 7	Hi, LuckyTran I attach you the heat flux contours and some other images that may be helpful for understanding my problem. [The images are in the next reply, I don't know how to remove this one] Last edited by crinoid; April 5, 2019 at 14:02. Reason: I hadn't uploaded the images

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April 5, 2019, 11:00		#2
LuckyTran Senior Member Lucky Join Date: Apr 2011 Location: Orlando, FL USA Posts: 5,675 Rep Power: 66	Are you sure....? What does the heat flux look like?

April 8, 2019, 13:59		#5
LuckyTran Senior Member Lucky Join Date: Apr 2011 Location: Orlando, FL USA Posts: 5,675 Rep Power: 66	Your temperature contour on the tip makes no sense. Check your setup. Boundary conditions? Is it coupled for the tip or other? It looks like it's not coupled.