Quasi-homogeneous and pseudospin modes of zirconium-wire combustion in air

A novel experimental technique is proposed for examining the transition mechanism from quasi-homogeneous to heterogeneous combustion – burning of a variable-pitch spring. Depending on the pitch of air-combustible zirconium springs, two combustion modes are possible. Quasi-homogeneous (layer-by-layer) combustion is observed in the case of small-pitch springs; as the spring pitch increases, quasi-homogeneous combustion transforms into heterogeneous (pseudo-spin) combustion. Conditions for the occurrence of various combustion modes, depending on the spring diameter and pitch, are studied.