Determination of the laminar burning velocities for mixtures of ethanol and air at elevated temperatures

Experimental test for premixed laminar combustion of ethanol-air mixtures has been conducted in a constant volume combustion bomb. The laminar burning velocities of ethanol-air mixtures are determined over a wide range of equivalence ratio at elevated temperatures, by means of the measurements of spherically expanding flames using schlieren photography technique. The effect of flame stretch imposed at the flame front has been discussed and the Markstein lengths are deduced to characterize the stretch effect on flame propagation. Following a linear relation between flame speed and flame stretch, the unstretched laminar burning velocities of ethanol-air flames have been derived. Over the ranges studied, a power law correlation has been suggested for the unstretched laminar burning velocities as a function of initial temperature and equivalence ratio. The empirical correlation is also compared with those data available in the literature, and it is found that the discrepancies are acceptable.