Sa. Elsayed, EFFECT OF HEATING A SEMITRANSPARENT MEDIUM BY RADIANT ENERGY ON IGNITION CHARACTERISTICS IN THERMAL-EXPLOSION THEORY, Journal of loss prevention in the process industries, 8(2), 1995, pp. 103-110
In ignition theory, there are no volume heat sources in a substance wh
ich is being heated through the surface. In most actual cases, ignitio
n occurs under more complex heating conditions. One of these heating c
onditions is the ignition of a semi-transparent body by the flow of ra
diant energy. This case is investigated, showing the effect of the pre
sence of volume heat sources of anon-chemical nature on critical and i
gnition conditions. The Arrhenius heat reaction law and the Frank-Kame
netskii exponential approximation for this law are also used. The igni
tion characteristics and transition conditions are demonstrated. The t
ransition conditions can be obtained from the condition d theta/d thet
a(a) = 0, as well as from d(2) psi/d theta(2) = 0. The results show th
at the critical point in the temperature-time plane can be obtained by
setting d theta/d tau = 0, d(2) theta/d tau(2) = 0, and d(3) theta/d
tau(3) = 0. The non-stationary solutions are also presented.