TO STUDY THE EFFECT OF PRESSURE AND TEMPERATURE ON LAMINAR FLAME PROPAGATION USING BIOGAS-AIR-HYDROCARBON MIXTURE

Abstract

Laminar flame propagation in it biogas- iso octane-air mixture has been studied in a constant volume bomb. The effect of initial parameters like initial pressure and temperature was analysed using pressure-tine history alone .Initial pressure was varied over a range from 1 atilt. to 4 atilt. and initial temperature was varied over a range of 303 K to 398 K. The iso octane percentage in the mixture was varied from 0-100% (on energy basis) to simulate the condition of engine combustion with dual fuel operation. The equivalence ratio of mixture was limited to one stoichiometric, O = 1.0) The pressure-time records have been used to calculate flame velocity using simplified two zone thermodynamic model. For each experimental run, instantaneous flame velocities were calculated in the range of 1.5 P,, to 0.75 P,,,ax and the flame velocity values between the burned mass fraction of 0.2 and 0.3 were averaged to get flame velocity value for a particular experimental run. It is found that for the biogas-iso octane- air mixture the flame velocity decreases with pressure and increases with ' temperature. With respect to iso octane addition, the flame velocity value increases up to a certain limit (20-30%) of iso-octane addition but with furt'her iso octane addition the flame velocity decreases under the present study. A comparison of the trends of tiame velocity variation with pressure with the results of other researchers who have worked on methane air mixtures shows reasonably good agreement