the flaming plastics (polyurethane)

the flaming plastics (polyurethane) fire and the flaming liquid (n-heptane) fire, before burning the
optical flow of polyurethane change from 0.10 to 0.18; the optical flow of n-heptane change from 0.12 to 0.21. And in the
middle stage of combustion the optical flow of polyurethane increase to 0.52 0.68; the optical flow of n-heptane increase
to 3.79 4.73.The changes before and after combustion are obvious. For the smoldering (pyrolysis) wood fire and the
smoldering Cotton fire, before the combustion the optical flows are small, in the middle of combustion, the optical flow of
wood will increase to about 0.54 and the optical flow of cotton will increase to about 0.83.