Laminar flame | Zifeng Weng

Spontaneous ignition of hydrogen jet

(More is coming)

Laminar flame speed

Supercritical laminar flame speed was studied for syngas for sCO₂ application. (More is coming)

Extrapolation relation

Relation between stretch rate and flame speed was derived via asymptotic analysis. The result obtained by Ronney and Sivashinsky [1] was extended from perfect gas to Noble-Abel gas.

\begin{equation} \label{eq:Evolution_S_R} \left(\frac{S}{1+b}\right)^{2}\ln\left(\frac{S}{1+b}\right)^{2} = -\frac{d}{dR}\left(\frac{S}{1+b}\right) + \frac{2}{R}\left(\frac{S}{1+b}\right) -\frac{d}{dR}\left(\frac{S}{1+b}\right) -l. \end{equation}

The Markstein length (number) was given as

\begin{equation} L_{b} = -\frac{\delta_{ad}I\beta}{2}= -\frac{\delta_{ad}\beta}{2}\int_{\varepsilon}^{1} \frac{1+b}{T^{0}+b}\left[\left(\frac{T^{0}-\varepsilon}{1-\varepsilon}\right)^{\mathrm{Le}-1}-1\right] {\rm d} T^{0}. \end{equation}

The extrapolation relation was validated with spherical flame simulation based on recently developed solver for real gas laminar flame.

The variations of flame speed with the Karlovitz number simulated with IG and NA EoS. The fresh mixture was stoichiometric H2-air.

Related publications

The effect of finite molecular volume on the propagation of unsteady spherical flame front

Zifeng Weng , Yakun Zhang , Brian M. Maxwell , and 1 more author

Combustion and Flame, 2024

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@article{SphericalFlame2024,
  title = {The effect of finite molecular volume on the propagation of unsteady spherical flame front},
  author = {Weng, Zifeng and Zhang, Yakun and M. Maxwell, Brian and M{\'e}vel*, R{\'e}my},
  year = {2024},
  journal = {Combustion and Flame},
  volume = {263},
  pages = {113404},
}

References

[1] P.D. Ronney, and G.I. Sivashinsky, “A Theoretical Study of Propagation and Extinction of Nonsteady Spherical Flame Fronts,” SIAM J. Appl. Math. 49(4), 1029–1046 (1989).