Geometric influence of perforated plate on premixed hydrogen-air flame propagation

Geometrical influence of the perforated plate on flame propagation in hydrogen-air mixtures with various equivalence ratios and initial pressures was experimentally investigated in a channel with the length of 1 m and the cross-section of 7 cm x 7 cm. The perforated plate has the same cross section and three thicknesses of 40 mm, 80 mm and 120 mm. High-speed schlieren photography was employed to capture the flame shape evolution and derive the flame tip velocity. High-speed piezoelectric pressure transducers were flush mounted upstream and downstream of the perforated plate to measure the pressure transient. It was found that, with the perforated plate in the path of flame, flame undergoes either "go", or "quench" propagation mode. The limit between these two was dependent on the geometrical size of the perforated plate and the initial conditions of mixtures. Both velocity and pressure were effectively attenuated with the increase in the perforated plate length. Moreover, for "go" propagation mode, the flame process through the perforated plate was characterized by three obvious stages: laminar flame stage, jet flame stage and turbulent flame stage. Whereas, only laminar flame stage was observed in the "quench" mode. (C) 2018 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.