DIRECT MEASUREMENT OF BURNING VELOCITY OF FLAME PROPAGATING IN FUEL-AIR HOMOGENEOUS MIXTURES IN A CLOSED VESSEL

The laminar burning velocity and the turbulent burning velocity of propane-air homogeneous mixture in a closed vessel were successfully measured from the difference between the flame propagation speed and the unburned gas velocity ahead of a flame front. The unburned gas velocity was measured with a laser Doppler anemometer. The flame propagation speed was determined by measuring the time of flame travel over a fixed distance. The flame front was detected by the refraction of a laser beam owing to the rapid change in the refractive index at the flame front. It was found that these measured values were reasonable as compared with the values determined from the configuration of flame and the pressure in the combustion chamber.