Conclusions 



Nonuniform ignition over the unit cell weakens the analysis. This effect was 

 minimized by choosing a small unit cell (3=0.08). The packing ratio here is represent- 

 ative of the upper range of packing ratios occurring in natural fuels. 



The heating efficiency required to bring fuel ahead of a fire to ignition as it 

 closes with the fire front has been investigated. Results show the dependence of e, 

 the fractional amount of the bulk density effectively brought to ignition, on the 

 surface area-to-volume ratio of the fuel in the bed. At present, these data provide 

 the only means for evaluating e. 



Structure and geometry have limited the number of sensing devices that can be 

 installed in fuel members without greatly altering the measurement. Therefore, more 

 thermocouples were placed in areas of greater sensitivity to the incoming flux. 

 Combined results from the temperature profiles of the longitudinal and transverse fuel 

 members provide a measure of the fractional amount of the bulk density that is involved 

 in the ignition process. These results are reasonably sensitive to the surface 

 area-to-volume ratio of the fuel member. 



14 



