Learning Forum

[n01469239]

Hello all, 

I am reaching out for some help on a problem I am having with an Ansys Fluent CFD simulation I am running. I am trying to pump heat into an enclosure using a heater source but I believe my boundary conditions on the wall shadow of my heater itself are what are giving me the wrong renderings. 

Attached below are some picture for reference. 

 

 

This is a temp plot along a critical part of the geometry of the enclosure. For reference, the walls with the holes on them represent velocity inputs and outputs to the enclosure.

 

This is where I thought the heater (the box in the upper right) would be dispersing heat throughout the enclosure. But it seems to being cut off at its geometrical extent. The red arrows are where I am trying to get the heat from the heater to go. 

 

This is the thermal boundary condition on the interface between the heater and the open air of the enclosure where I though it having  “coupled” thermal conditions meant it was 1 to 1 heat transfer. 

 

Any suggestions, tips, or help, on how I could get the heater to disperse heat throughout my enclosure is greatly appreciated. Please let me know if you guys need any ouhter information for me.

 

Thank you!

[Essence]

 

Hello,

If you have wall as a heater, you can specify heat flux. But this heat flux will not have any convective part. If you need convection along with heating, use inlet BC. This is because, for the heat from the heater to be dispersed along the direction, you need a carrier (fluid) from heater to the enclosure air. Therefore, please ensure the inlets are properly defined. If you have natural convection, please turn On the gravity term.

[n01469239]

I have an inlet BC. The two red arrows, in the picture above, in -X coordinate direction are the air velocity I have converging in the center of the enclosure then funneling in the -X direction. Do i need the gravity term for forced convection?   But if I understand your information correctly that velocity is enough to disperse the heater throughout the enclosure. 

From my understanding, it looks like the heat isn’t passing out of the heater at all.

Another option I could try is try to put natural convention over the wall of the heater.

Please let me know what you think, and I thank you for your very helpful information so far.

[Essence]

If the -X velocity is high enough, you won't have sufficient heat getting transferred to entire enclosure. The diffusivity of heat will be lower.