Effect of Porous Wall on Detonation Propagation Velocity in Hydrogen-Oxygen Mixtures

In this paper, the effect of flexible and rigid porous wall on the detonation propagation velocity in hydrogen-oxygen mixtures is investigated systematically. The roles of hydrogen concentration, initial pressure, porous wall geometry and porosity are considered in detail. Pressure sensors are used to record the time-of-arrival of the detonation wave, and the average velocity of the detonation wave can be obtained. The results indicate that the detonation propagation limit in a tube filled with porous materials is shorter than the value obtained in a smooth tube, and the velocity deficits increase obviously with the increase of the porosity and thickness. In the detonation limit, the velocity of detonation wave decreases firstly and then rises after passing through the absorption wall, which is due to the reflection of the shock wave on the surface of the wall. The reaction rate is increased quickly by introducing the local disturbance in the reaction zone, compensating the adverse effects of the porous wall. Compared with changing porosity, increasing thickness has a more significant effect on detonation attenuation. This phenomenon can be due to the excessive bending of the wave front and the heat loss increases.