Experimental Research on Expanding Turbulent Flames of Lean Methane/Hydrogen/Air Mixtures

Evolution of expanding turbulent flames of lean methane/hydrogen/air mixtures under strong turbulence intensity was obtained using a constant volume, fan-stirred turbulent combustion chamber. And the turbulent flame propagation characteristics were investigated under negative Markstein number conditions. It is found that the propagation of expanding flame is self-similar. The flame propagation is affected by flame instability even unthin intense turbulence. Furthermore, the effect of instability on expanding turbulent flame increases as the decreasing of Markstein number. A new correlation for turbulent burning velocity is obtained with the consideration of the flame instability effect under negative Markstein number conditions.