Promoting of foam copper with chaotic distributed pores on the deflagration of premixed hydrogen-air flame in the tube

Abstract

The deflagration flame of stoichiometric hydrogen-air mixtures is studied in this paper. Combined with the foam copper structure, the deflagration characteristic is analyzed in this paper. The experimental results show that the foam copper can improve the flow instability at the flame front and the degree of turbulence in the propagation process, the flame propagates more rapidly in turbulence state, and the number of stages of flame morphology during the propagation process increases. The classic ?tulip? flame can be transformed into a distorted ?tulip? flame and a fractal ?tulip? flame before it collapses. When the flame passes through the foam copper, the flame front velocity increases as the number of structural layers increases. The flame front velocity propagates at supersonic speed through the accumulation of three layers of foam copper. The instability of overpressure in the propagation process will cause oscillation. More layers of the structure, the oscillation frequency, and the amplitude of the overpressure are increased significantly. Foam copper structure has a reverse action on overpressure. When the overpressure value is low in the early stage, the structure promotes the propagation, but the overpressure value is large in the later stage, the structure has a blocking effect.