Negative heat flow and radiation in steady state thermal

  • 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. 




Kremella posted this 23 August 2018


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,