Theory
The shell is the first planar layer of a heat-loss wall; the solver receives its thickness and this conductivity (thicknessLayers, kappaLayers of externalWallHeatFluxTemperature). The resistance of the layer is . With "User defined" there is no library emissivity: on auto the emissivity becomes 0.8 (the oxidised-steel value), so set Emissivity for a bright or coated surface.
Equations
(1)
| where | meaning | unit |
|---|---|---|
| Shell resistance per unit area | m² K/W | |
| Shell thickness (Shell thickness) | m | |
| Shell conductivity (this setting) | W/(m K) |
Default and rule
- Default
- 20 W/(m K) in the box (material 'User defined' only)
- Rule
20 W/(m K) in the box (the stainless-steel value); required when the material is "User defined".
- Source
The conduction resistance is elementary; the conductivity is passed to
externalWallHeatFluxTemperatureaskappaLayers.
Valid range > 0
Values
Positive. Steels 15-50, aluminium about 150-200, cast iron about 50 W/(m K).