Dynamics of flame propagation from localized ignition in rich hydrogen/air mixtures: Effects of elevated pressure and temperature

A computational study on expanding spherical premixed flames was conducted to investigate the dynamics of the stretch-affected, one-dimensional, and pulsating instability. Using a time-dependent, spherically symmetric code with detailed chemistry, transport, and radiation submodels, rich H₂/air mixtures were investigated. It was shown that the dynamics of spherically expanding flames was significantly different than that for planar flames. It was suggested that any consideration of flame propagation ignition must address the competition between excess enthalpy from external energy deposition and stretch/heat-loss-affected pulsation instability.