Experimental Study and Kinetic Modeling of Laminar Flame Propagation in Premixed Stoichiometric n-butane-air Mixture

Venera Giurcan,Domnina Razus,Maria Mitu,Dumitru Oancea

doi:10.37358/rc.19.4.7077

Abstract

The laminar burning velocities and propagation speeds of stoichiometric n-butane-air mixture were obtained for outwardly propagating spherical flames by measurements of pressure rise during the early stage of propagation in a spherical vessel. The experiments were carried out at various initial pressures within 0.3 and 1.2 bar, and various initial temperatures within 298 and 423 K. The experimental laminar burning velocities were compared with those provided by the detailed kinetic modelling based on Warnatz mechanism for combustion of C1-C4 hydrocarbons, using INSFLA package. The baric and thermal coefficients of laminar burning velocities, calculated from their dependence on initial temperature and pressure, were compared with coefficients characteristic for other fuel-air mixtures. The overall activation parameters (reaction order and activation energy) are reported and discussed in comparison with similar data characteristic for alkane-air flames.

Highlights

The laminar burning velocities and propagation speeds of stoichiometric n-butane-air mixture were obtained for outwardly propagating spherical flames by measurements of pressure rise during the early stage of propagation in a spherical vessel
The present paper reports the laminar burning velocities and propagation velocities of the stoichiometric n-butaneair mixture determined by measurements of pressure rise during the early stage of outwardly propagating spherical flames, in experiments at various initial pressures (0.3 1.2 bar) and temperatures (298 - 423 K)
At ambient initial temperature and pressure the laminar burning velocity of the stoichiometric n-butane-air was sfotruentcdh-Scuo,0r=rec3t8e.d4 cm s-1, burning in very good agreement with velocities reported in literature: 38.0 cm s-1, obtained with the heat flux method [13,14]; 37.1 cm s-1, obtained with the counterflow twin flame method [15] and 36.9 cm s-1 [18]

Summary

Experimental laminar burning velocities

A simple way to determine the laminar burning velocity of a fuel-air mixture is to restrict the examination of flame propagation to the early stage of an outwardly propagating flame, when the temperature gradients in both unburned and burned gas are small and can be neglected. This simple method is based on the relationship between the pressure increase in the early stage ∆p and the time from ignition, t [33]: REV.CHIM.(Bucharest)♦70♦ No 4 ♦2019.

The results are d temperatur given in table e range the

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Conclusions