Learning Forum

[yeongseok choi]

My 3D model looks like a cylinder and the energy is created at the center of the cylinder.

And inside the cylinder is a vacuum state.

I want to check the temperature of the outside of the cylinder surface.

But in my model, the surface didn't get the heat.

 

Now I wonder if there is any option or setup to work properly or if I never get this result with a steady state.

[peteroznewman]

Please reply with a cross-section of your geometry to clarify some questions.

It sounds like you have a closed-end cylindrical tube with some wall thickness and a vacuum on the inside.

Is there a second body at the center of the vacuum space?  If so, does that body have a Heat Generation Rate in watts?  Or does that body have a specified surface temperature?

On the outside surface of the closed-end cylindrical tube, I assume that is exposed to some kind of large body of fluid that is kept at some environmental temperature. Is that correct? In that case, you will use a Convection boundary condition on thoses surfaces.

Since there is a vacuum on the inside of the closed-end cylinder, the only heat transfer mechanism to send head from the second body inside that space to the inner walls of the closed-end cylinder is by a Radiation boundary condition.

Please watch this training course for an example much like yours.

https://courses.ansys.com/index.php/courses/topics-in-heat-transfer-analyses/lessons/how-to-model-thermal-radiation-between-surfaces-lesson-3/