刚性和柔性多孔材料作用下氢气爆轰胞格结构的演化规律

As highly efficient absorbing and dissipating materials, porous materials were widely used in the study of detonation wave attenuation. In order to further explore the mechanism of explosion suppression by porous materials, the effects of typical flexible (sponge) and rigid (wire mesh) porous materials on the detonation cellular structure for hydrogen and oxygen mixture were investigated systematically. The effects of thickness and porosity of sponge and wire mesh on the structure and size of detonation cell were discussed in detail. The cellular pattern of detonation wave was recorded by using smoke plate technology, and the cell size was calculated. The pressure sensors were used to record the arrival time of the detonation wave, and the average propagation velocity of detonation wave was obtained. The results show that the detonation cellular structure closely depends on the thickness and porosity of sponge and wire mesh, and three phases of the propagation can be observed in the tube, including detonation failure, acceleration and re-initiation. In addition, size of the detonation cell is also closely related to the thickness and porosity of sponge and wire mesh. Increasing the thickness of porous materials and decreasing the porosity both can increase the size of the detonation cell. By comparing the effects of sponge and wire mesh on the detonation cellular structure, it can be found that at the same initial condition, the rigid porous material has a stronger inhibition effect on detonation. But the difference will be gradually decreased with the increase of the thickness of the porous materials. Finally, the limit of the detonation propagation is analyzed quantitatively by introducing the dimensionless parameter D_H/λ. For flexible and rigid porous materials, the detonation limit can be nearly quantified as D_H/λ≈3.0 and D_H/λ≈3.1.