MEASUREMENT OF LAMINAR BURNING VELOCITY OF METHANOL .AIR MIXTURE

Abstract

An experimental study on the effects of pressure, temperature and equivalence ratio on the laminar burning velocity of methanol-air mixture has been conducted using the constant volume bomb method. The range of measurements covered the equivalence ratio from 0.8 to 1.2, the mixture pressure from 1 to 4 bar, while the initial temperature varied from 300 to 400 K. The pressure-time records have been used to calculate laminar burning velocity using simplified two zone thermodynamic model. For each experimental run, instantaneous burning velocities were calculated in the range of 1.5 Po to 0.75 Pmax and the laminar burning velocity values between the burned mass fraction of 0.2 and 0.3 were averaged to get burning velocity value for a particular experimental run. It is found that for the methanol-air mixture the laminar burning velocity decreases with pressure and increases with temperature. With respect to equivalence ratio, the burning velocity value is relatively small with lean mixture but . this increases continuously as the mixture is made progressively richer upto stoichiometric ratio and a little beyond (o -- 1.075), and again begins to drop down with increasing mixture richness. A comparison of the trends of laminar burning velocity variation with pressure with the results of other researchers who have worked on methanol-air mixture shows reasonably good agreement. This agreement gives confidence in the result of the present study to conclude the effects of various parameters on laminar flame propagation of methanol-air mixture.