Formula 8.34

Radiation shields

Input(s)

$\mathrm{k}$: Stefan-Boltzmann Constant $\left(\mathrm{BTU} / \mathrm{s} \mathrm{ft}^{2}{ }^{\circ} \mathrm{R}^{4}\right)$

$T_{i}$: First Sheet's Temperature (K)

$T_{i+1}$: Next Sheet's Temperature (K)

$Q_{i, i+1}$: Heat Transfer Rate (BTU/s)

Output(s)

$R_{i, i+1}$: Resistance to Radiation $\left(\mathrm{ft}^{2} \mathrm{~K} / \mathrm{W}\right)$

Formula(s)

$$ \mathrm{R}_{\mathrm{i}, \mathrm{i}+1}=\frac{\sigma *\left(\mathrm{~T}_{\mathrm{i}}^{4}-\mathrm{T}_{\mathrm{i}+1}^{4}\right)}{\mathrm{Q}_{\mathrm{i}, \mathrm{i}+1}} $$

Reference(s)

Bird, R.B., Stewart, W.E. and Lightfoot, E.N. (2002). Transport Phenomena (Second Ed.). John Wiley \& Sons, Chapter: 16, Page: 509.