Free Convection in a Light Bulb. The model solves for the temperature distribution and the flow...

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


• 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


• Argon gas treated as an ideal gas

• When the light is turned on, the gas heats and induces a flow


• The filament heats rapidly over the first seconds• Pictures shows temperature over the first 10 seconds

t=2s t=6s t=10s


t=2s t=6s t=10s

• Induces a flow driven by natural convection• Pictures shows velocity field over the first 10 seconds


• Temperature on the boundary heats slowly


• Radiative heat flux on the outer boundary

Free Convection in a Light Bulb. The model solves for the temperature distribution and the flow...

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