Effect of ignition position on premixed hydrogen-air flame quenching behaviors under action of metal wire mesh

Abstract

For obtaining effective inhibitory strategies for hydrogen combustion in terms of safety, the effect of ignition position on premixed hydrogen-air flame quenching behaviors under action of metal wire mesh is experimentally analyzed. Combustible hydrogen/air gases with volume ratio of 2:3 is adopted. Metal wire mesh of 60 meshes-60 layers is selected as the flame inhibitory structure. Three different ignition positions are arranged for obtaining different stages of flame entering suppression section. The results indicate that ignition position affects flame quenching results significantly. The flame quenching difficulty increases as the distance between ignition position and wire mesh location increases. Besides, the ignition position influences flame behaviors greatly. Tulip flame is actually led by the vortices in IP1 case, and the internal mechanism is attributed to the interactions of flame front and pressure waves. However, for IP3, the special tulip flame with an extremely long inversion cusp is actually led by the enhanced reverse gas flow in burnt field, and the root cause is metal wire mesh enlarges the discrepancies of combustion intensity between flame propagating toward positive and negative directions. Moreover, the ignition position changes flame tip speed and pressure greatly. As ignition position changes from IP1 to IP2 and IP3, the maximum flame tip speed toward positive direction decreases from 120.5 m/s to 105.2 m/s and 56.9 m/s, separately. Also, the maximum pressure reduces from 0.13 MPa to 0.08 MPa and 0.07 MPa, respectively, which further proves a more pronounced inhibitory effect when setting ignition position closer to wire mesh.