BC for Natural Convection around an incandescent light bulb
 

Hello everyone,

I`m simulating the flow and heat transfer inside and around an incandescent light bulb.

I`ll give a short overview of my setup.

I want to simulate the heat transfer of a light bulb and compare it with thermographic measurements that were done one the same type of bulb.

My Setup up so far:

Coil:

I aproximate the coil with a cylinder of the diameter of the coil. The cylinder is a heat source in my simulation.

Bulb:

The bulb is my secondary fluid zone filled with argon.

Glas:

The glas is a zero thickness wall with shell conduction turned on.

Volume around the bulb:

The volume around the bulb is air. The flow is just a result by natural convection caused by the heating of the bulb.

The Volume is surounded by a Cube.

Outlet/Inlet:

I have a pressure outlet (0 Pa gauge pressure) above and a pressure inlet (1.5 Pa gauge pressure) below the light bulb. The pressure difference is because of the hydrostatic pressure difference between the outlet and the inlet.

Both fluids are compressible and of course gravity is turned on.

My question now is: What boundary condition should the faces of my cube be, that is surounding the volume around my light bulb? I already did a simulation using the symmetry condition for the cube walls, but I`m not sure if i can do that.

Would pressure-far field be better? And do I have to establish a pressure profile for these faces (because of the hydrostatic pressure distribution)?

At this point my resulting temperature distribution is roughly 40K lower than that of the measured result.

Kind regards,

Sebastian