THEORETICAL EVALUATION OF THE FLAME VELOCITY FROM EXPERIMENTALLY OBTAINED PRESSURE-TIME PLOTS

Abstract

Knowledge of laminar flame velocity is useful in understanding various combustion problems. In the present work the pressure-time plots obtained experimentally, have been used to calculate laminar flame velocity, with the use of simplified, two zone thermodynamic model. An identification algorithm which uses the model has been developed for the determination of laminar flame velocity from the measure of pressure increase only.. The software developed in c-language based on theoretical model will be useful in determining laminar flame velocity, burned mass fraction, burned gas temperature for different hydrocarbon air mixtures at various initial conditions of pressure, temperatures and equivalence ratio. Presently the• calculated flame velocities• have been plotted against initial temperature for isooctane-air mixture and bio gas air-mixture. The graphs show that flame velocity decreases with increase of initial temperature, which is comparable with the values obtained by different workers with constant volume bomb method. A comparison of the trends of flame velocity variation with pressure and unburned gas temperature, with the results of other workers for isooctane-air and C114-air are shown. Which show reasonably good agreement which provides a base for the software developed presently for the determination of laminar flame