Consider an average windspeed over the height range H to H + Hp, where Hp is the 

 extension of the flame above the fuel bed. 



H + Hr 



U = tV 



U dz = 1 



^ °^ Hp K 



H + Hp I D \ 

 H 



dz 



(5) 



let X = 



Hp K 



/ 



z 







!in X dx = -q— ■j<^ ^ (2.nx-l) 



U = H 



F ^ ' ^ 



H + H, 



(6) 



Note that at the lower limit (H) the value is nearly zero since: 



" \ 0.13H / ' 



(7) 



Thus we find 



- H + Hp - 0.64H 



in 



/H + Hp - 0.64H\ 

 \^ 0.13H ~ J 



-1 



U 



r ^ 0-36 Fp) ^"(--w— j 



(8) 



4 



