Burning Velocity of Propane-Air Mixtures from Pressure-Time Records during Explosions in a Closed Spherical Vessel

The flame propagation during the deflagration of the propane air mixtures with variable initial concentration, pressure, and temperature ([C3H8] = 2.60-6.20 vol %, p(0) = 30-200 kPa, and T-0 = 298-433 K) in a spherical closed vessel with central ignition was monitored by means of pressure measurements. Using an improved relationship for the burnt Mass fraction, the burning velocities were calculated from pressure time records over an extended duration of spherical propagation. A very good agreement was found between the burning velocities of atmospheric laminar C3H8/air flames and literature data. Computed burning velocities, obtained from numerical modeling of one-dimensional laminar flames using two detailed chemical kinetic schemes (Warnatz mechanism and GRI Mech 3.0, respectively) are discussed in comparison to experimental burning velocities. The measured burning velocities are correlated with pressure and temperature using a power law; the baric and thermal exponents, nu and mu, lie within the usual range characteristic to alkane air-laminar flames.