The propagation of a lean hydrogen-air isobaric flame in a quiescent mixture contained between two parallel plates closed on one side (named Hele-Shaw chamber) is investigated numerically.
Making use of three-dimensional (3D) simulations with detailed chemistry and transport we examine the effect of the distance between the plates, h, on the dynamics and the overall propagation speed of the flame. In term of the characteristic flame thickness, δf, the distance h takes the values h=0.1δf, h=0.5δf, and h=δf.
We also use a quasi-two-dimensional (quasi-2D) approximation formulation based on Darcy’s law (valid in the limit of small h) for comparisons with the full set of 3D equations. From the 3D simulations we observe a strong cell splitting and merging dynamics for h=0.1δf, while for larger h the cell dynamics suffers a much smoother evolution. In the case h=1δf, the flame is non-symmetric along the h direction which considerably increases the flame propagation speed.
For the smallest distance h=0.1δf the 3D and quasi-2D numerical simulations exhibit very similar results.
Title: Three-dimensional simulations of lean H2-Air flames propagating in a narrow gap: on the validity of the quasi-two-dimensional approximation
Authors: J Melguizo-Gavilanes, D Fernández-Galisteo, A Dejoan, M Sánchez-Sanz, V Kurdyumov
International Conference on Hydrogen Safety Sep 2021, Edinburgh, United Kingdom. ffhal-03424213
Publication date: September 2021.
You can read an excerpt here