Numerical study on the stabilization of ball-like reacting fronts at normal gravity*

A computational investigation on the stabilization and dynamics of lean premixed flames in tubes at near lean-limit conditions is conducted. Hydrogen-methane-air premixed mixtures are considered in tubes with two different diameters (13.5 and 55 mm) and under the influence of normal gravity. As the lean flammability limit is approached, individual (13.5 mm tube) and multiple (55 mm) ball-like flames are formed and stabilized. Through high-fidelity simulations with detailed transport and chemical models as well as the inclusion of heat losses, the stabilization and dynamics of such flames are examined.