Cableizer ®

Heat transfer coefficient radiation

Heat transfer coefficient for radiation in channel acc. Heinhold eq. 18.21

Symbol
$\alpha_{st}$
Unit
W/(K.m$^2$)
Formulas
$\frac{K_{t} \sigma \left(\left(\theta_{de}+\theta_{abs}\right)^4-\left(\theta_{t}+\theta_{abs}\right)^4\right)}{\Delta \theta_{s}}$
Related
$\Delta \theta_{s}$
Temperature difference surface—ambient [K]
$K_{t}$
Effective emissivity object surface
$\sigma$
Stefan Boltzmann constant [W/m$^2$K$^4$]
$\theta_{abs}$
Absolute temperature [K]
$\theta_{de}$
Temperature duct outer surface [°C]
$\theta_{t}$
Temperature wall (inner) [°C]
Used in
$T_{st}$
Thermal resistance radiation object—tunnel [K.m/W]