Post-Ignition Burning of Horizontal Wood Surfaces.

The effects of wind speed control and variable radiation input on the ignition and continued burning of horizontally mounted white pine wood pieces were investigated. The wind velocity and radiation energy input were varied before and after ignition in programmed sequences. The input flux reduction caused by pre-ignition smoke production was related to the wind velocity. Ignition times were measured with moderate wind, and ignition was prevented with certain wind velocities and heat flux. Measurements made with a calorimeter mounted in the test samples indicated how flame intensity increased with continued burning. Flame radiation intensity was also related to the amount of wind. Measurements were made to determine the amount of energy required to sustain burning after ignition, indicating a minimum amount and rate of energy input necessary for any given time of continued combustion.