In a weakly constrained, confined space, four common ignition sources—electrical spark, open flame, tungsten filament, and electrochemical igniter—were employed to investigate how the ignition mode influences the overpressure and flame-propagation characteristics during the vented explosion of gasoline vapor. The results show that the explosion process can be divided into four stages, featuring three typical overpressure peaks. The flame velocity exhibits two pronounced accelerations: one upon rupture of the vent membrane and another when the flame reaches the vent opening. Among the ignition sources tested, the electric spark produced the most severe destructive effects associated with overpressure, while the electrochemical igniter yielded the fastest flame propagation, and the tungsten filament ignition generated the longest external flame, constituting the greatest external fire threat. Explosions initiated by the tungsten filament and electrochemical igniter experience flame instability at the outset, induced by disturbances from the ignition source itself.
Li et al. (Sat,) studied this question.