Negative heat flow and radiation in steady state thermal

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  • Last Post 23 August 2018
Csongor Varadi posted this 21 August 2018

Dear ANSYS users,

 

I'm trying to simulate the cooling of an aluminium block inside a vacuum chamber by using a meander fixed to a copper plate (See screenshots below). For boundary conditions I have set a heat flow on the inside of the piping with -112.5 W, and a radiation on the inside enclosure of the vacuum chamber with an ambient temperature of 20°C and an emissivity of 0.8. Initial temperature is set to 20°C. The outer surface of the chamber is set to a temperature of 20°C.

If I set the heat flow to be positive (i.e. heating) the simulation converges just fine, however if I use a negative heat load the simulation fails to converge, or does so extremely slowly. The problem might lie with the radiation boundary condition, however I am somewhat stuck and can't progress with the issue, so any help would be appreciated. 

Cheers,

Csongor

 

Kremella posted this 23 August 2018

Hello,

What is the direction of heat flow in your problem? A positive value indicates heat flow into the node, while a negative value indicates out of the node.

Have you tried to isolate the problem by switching off the radiation heat transfer? 

Also, could you please help us understand your problem a little better? What are you looking to model?

Thank you.

Best Regards,

Karthik

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