Combustion characteristics of methane/n-decane mixed fuel

In order to study the combustion characteristics and combustion stability of CH4/n-decane mixed fuel, the diffusion velocity of flame radius, the stretched flame speed, Marksein length, unstretched flame speed and laminar burning velocity of CH4/n-decane mixture were measured experimentally in a constant volume chamber at initial pressure of 0.1MPa, initial temperature of 420K, over the equivalence ratios range of 0.8－1.5 and over the methane concentration range of 0－0.8. The influences of methane concentration on Marksein length and laminar burning velocity were investigated. Results showed that at equivalence ratio of 1.3, the observed cellular structure at the end of flame propagation disappeared with the increase of methane concentration and the flame front became smooth, along with the increase of the flame stability; the decreasing trend of Marksein length with the growing equivalence ratio became slower due to the increase of methane concentration, and there was a critical equivalence ratio, with the methane concentration of 0.8 the combustion stability was poor when the equivalence ratio was smaller than 1.2 and to the contrary the combustion stability was better when the equivalence ratio was bigger than 1.2; over the equivalence ratio of 1.0－1.3 the laminar burning velocities of mixed fuel with methane concentration of 0.2 and 0.4 were faster, and over the equivalence ratios range of experiment conditions the laminar burning velocities of mixed fuel with methane concentration of 0.8 were slower.