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Stefan Boltzmann constant

The Boltzmann constant is the physical constant of proportionality in the Stefan–Boltzmann law, which states that the total intensity radiated over all wavelengths of a black body is proportional to the fourth power of the thermodynamic temperature.

Symbol
$\sigma$
Unit
W/m$^2$K$^4$

Default
5.67036713e-08

Used in
$\alpha_{st}$
Heat transfer coefficient for radiation [W/(K.m$^2$)]
$h_{rad,ce}$
Radiation heat transfer coefficient, conductor to enclosure [W/(K.m$^2$)]
$h_{rad,ext}$
Radiation heat transfer coefficient, duct to air [W/(K.m$^2$)]
$h_{rad,int}$
Radiation heat transfer coefficient, object to duct [W/(K.m$^2$)]
$h_{rad,sa}$
Radiation heat transfer coefficient, surface to air [W/(K.m$^2$)]
$T_{st}$
Radiation thermal resistance, surface to tunnel [K.m/W]
$W_{rad,ce}$
Radiation heat transfer, conductor to enclosure [W/m]
$W_{rad,ext}$
Radiation heat transfer, duct to air [W/m]
$W_{rad,int}$
Radiation heat transfer, object to duct [W/m]
$W_{rad,sa}$
Radiation heat transfer, surface to air [W/m]