1. Free Convection in a Light Bulb

2. Free Convection in a Light Bulb
The model solves for the temperature distribution and the flow field inside a light bulb
Axisymmetric model, accounts for conduction, convection, radiation and nonisothermal flow
Model shows how to model free convection, how to treat ideal gasses, and how to model radiation

3. Free Convection in a Light Bulb
Tungsten filament approximated with a solid torus to allow modeling in 2d
Surface-to-surface radiation at interior boundaries
Surface-to-ambient radiation at outer boundaries

4. Free Convection in a Light Bulb
Argon gas treated as an ideal gas
When the light is turned on, the gas heats and induces a flow

5. Free Convection in a Light Bulb
The filament heats rapidly over the first seconds
Pictures shows temperature over the first 10 seconds
t=2s
t=6s
t=10s

6. Free Convection in a Light Bulb
Induces a flow driven by natural convection
Pictures shows velocity field over the first 10 seconds
t=2s
t=6s
t=10s

7. Free Convection in a Light Bulb
Temperature on the boundary heats slowly

8. Free Convection in a Light Bulb
Radiative heat flux on the outer boundary

9. Free Convection in a Light Bulb