Abstract
The present work reports the measurement of the laminar burning velocity of liquefied petroleum gas (LPG)-air mixtures at high temperatures using the planar flame propagation mode appearing in the preheated mesoscale diverging channel. The experiments were carried out for a range of equivalence ratios, 0.7 <= Phi <= 1.3. The present data for LPG-air mixtures are reported for a temperature range of 370-650 K in comparison to maximum mixture temperatures of 400 K reported in the literature. Experimental studies complimented with computational studies for conditions similar to present experiments confirm that the effect of heat loss from flame to channel walls on burning velocity is minimal and measured burning velocities are nearly equal to adiabatic burning velocity. The stabilized flame is nearly flat in both transverse and depth directions. The power law form of correlations from present experiments help in understanding the variation of laminar burning velocity with mixture temperatures and equivalence ratios. An increase in mixture temperature significantly enhances the burning velocity. Maximum burning velocity is obtained for slightly rich mixtures, unlike for the highly rich mixtures reported in the literature. A minimum value of the temperature exponent is observed for slightly rich mixtures.