One- and two-sided burning of thermally thin materials

The rate of heat release from a thermally thin material burning on both sides will be more than twice the value seen when only one side is burning. Two simplified models demonstrate that this is a consequence of the Arrhenius temperature dependence of the gasification rate of the solid. Experiments carried out on three composite materials over a range of incident heat fluxes confirm this effect. It is inferred that a further consequence of this heat release enhancement is an increased tendency for concurrent flame spread in the two-sided burning case. Materials whose application could lead to two-sided burning should thus be assessed in this mode to obtain a true picture of their flammability potential.