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Untitled - Aerobib - Universidad Politécnica de Madrid

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144 CHAPTER 6. LAMINAR FLAMES<br />

a) Reaction zone.<br />

After substituting (6.34) into (6.26), we have<br />

dθ<br />

dξ = θ i − θ 0<br />

1 − θ 0<br />

(1 − θ), (6.46)<br />

where the following dimensionless distance was introduced<br />

being<br />

ξ = x l , (6.47)<br />

l =<br />

λ<br />

mc p<br />

(6.48)<br />

a characteristic length of the wave. The integration of (6.46), once it is assumed that<br />

reaction starts at point x = 0, gives<br />

Likewise, one obtains for ε and Y<br />

1 − θ = (1 − θ i ) e −θ i − θ 0<br />

1 − θ i<br />

ξ<br />

. (6.49)<br />

1 − ε = e −θ i − θ 0<br />

1 − θ i<br />

ξ<br />

, (6.50)<br />

1 − Y =<br />

(<br />

1 + 1 ) −1<br />

θ i − θ 0<br />

e −θ i − θ 0<br />

ξ<br />

1 − θ i . (6.51)<br />

L 1 − θ i<br />

1.0<br />

0.8<br />

Y(L=0.5)<br />

0.6<br />

ε, Y<br />

0.4<br />

Y(L=1)<br />

ε<br />

0.2<br />

Y(L=2)<br />

0.2 θ 0.6 0.8 1.0<br />

i<br />

=0.4<br />

θ =0.125 0 θ<br />

Figure 6.3: Distributions of Y and ε as a function of θ when the activation energy is zero.

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