Transition from turbulence-dominated to instability-dominated combustion regime in lean hydrogen-air flames
Fluid Dynamics
2023-03-14 v1
Abstract
Recent complex-chemistry direct numerical simulations of lean hydrogen-air flames propagating in forced turbulence in a box were continued by switching-off the turbulence forcing. Results show that a decrease in burning velocity U_T(t), caused by the turbulence decay, is reversed when the turbulence becomes weak and a peak of U_T(t) appears, with the peak magnitudes and associated Karlovitz numbers being similar in two different cases. These results (i) are attributed to activation of laminar flame instabilities, which have been suppressed by intense turbulence, and (ii) are argued to indicate that the instabilities can substantially affect U_T in sufficiently weak turbulence only.
Keywords
Cite
@article{arxiv.2303.07057,
title = {Transition from turbulence-dominated to instability-dominated combustion regime in lean hydrogen-air flames},
author = {Hsu Chew Lee and Peng Dai and Minping Wan and Vladimir A. Sabelnikov and Andrei N. Lipatnikov},
journal= {arXiv preprint arXiv:2303.07057},
year = {2023}
}