Learning Forum

[ehkh]

Hi,

I am trying to a 3-D case to model a transient laminar heat transfer and compare the results with experimental one. In my case, the bottom layer is subjected to constant heat flux 1000W (temperature at 3000K) while the side wall are insulated and the top is free surface.

the experimental setup as follows:

The tank is made of double glass sidewalls with 6mm air gap to ensure thermal insulation. The bottom of the tank is made of black anodized aluminium, the under side of the base is insulated with a source of heat  of 1000-W halogen lamp (colour temperature of 3000 K).

My questions are:

What type of thermal boundary condition I need to set up for the insulated walls? does mixed BC works in this case or I need to define a new material for the side walls with insulation properties?

For the bottom layer I have tried either to apply constant heat flux or constant temp (not combined as in the user guide) and simulate for 200 timesteps (10 sec) but I didn't get plumes at the bottom layer, Do I need to use a S2S radiation in this case? what are the best options to apply similar source of heat at the bottom?

Additionally, do I need to specify  a value for the Heat Generation Rate when specifying the temp or heat flux at the bottom layer.

any help would be appreciated.

 

Thanks

 

 

[Rob]

Which solver are you using? 

[ehkh]

Pressure based solver

[Rob]

I assume that's in Fluent, thanks. 

Read up on the wall boundary conditions in the Fluent User's Guide, that'll give you a good idea about which boundary and what values to use. 

For buoyant plumes, I assume you added a temperature dependent density & turned on gravity?