Premixed flame propagation characteristics in a supersonic airstream

Measured values of flame angles are presented to aid the design of premixed combustion chambers and prediction of flame propagation. Flame spread, velocity, and dependence of burning rate on the properties of unburned flow and on turbulence levels are compared with the measured values. The premixed flame angle is found proportional to the amount of heat released, and correlates readily with the fuel mixture ratio through the rate of heat release or rate of water formation. Finite rate combustion affects flame angle mostly at off-stoichiometric conditions. The pilot affects the flame angle if abundant unburnt fuel is present in the pilot hot gases. Viscosity runs several times over the rated level.