Fire Safety Science Digital Archive

The Frank-Kamenetskii thermal explosion parameter, ?c, is calculated for rectangular parallelepipeds with sides in the ratio of 1:p:q. It is given by:- ?c = 0.873(1+1/p^2+1/q^2). The coefficient includes a small correction to give agreement to within 1 per cent of existing values of ?c for the extreme configurations, i.e. the cube when p=q=1 and the infinite plane slab when p=q=?.