Experimental investigation on the effect of a barrier wall on unconfined hydrogen explosion

27 m3 unconfined hydrogen explosion experiments are conducted to investigate the effect of barrier wall on explosion characteristics. The results show that the flame propagation velocity is highly related with the development of the flame instability, not only dependent on the laminar burning velocity. In front of the wall, due to the wave reflection, the overpressure peak Pmax and positive overpressure impulse IP increase while the positive overpressure duration time tdur decreases. In the rear of the wall, due to the wave diffraction, Pmax and IP decrease while tdur increases. The time reaching overpressure peak tpeak increases on both sides of the wall. Pmax is about twice the incident overpressure on the wall surface because of the pressure reflection. The enhancement or mitigation effect of the barrier wall only works in a certain range. The mitigation effect is highly related with the relative height between gas cloud and barrier wall.(c) 2023 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.