Radiation Effects on Burning

Surfaces are opaque and approach emittance and absorptance of unity. 

External radiant flux is not affected by the flame, e.g. thin flame. 

Flame incident radiant flux ( r) and total radiant energy (XtQ) might be estimated from measurements. 

External radiant heat flux (q ) is expressed as that measured by a heat flux meter maintained at Too. Correspondingly, the surface loss is given with respect to T as 

If we can define the radiative terms a priori, we are simply adding a constant to the RHS. An expedient transformation reduces the boundary condition to its original convective form  

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