Effects of the pore size on hydrogen-air detonation propagation in the channel with porous walls

We considered the problem of detonation suppression and weakening of the blast wave effects occurring during the combustion of hydrogen-air mixtures in the confined spaces. Detonation decay in hydrogen-air mixture was experimentally investigated in rectangular cross-section channels with four types of foam polyurethane with a number of pores per inch ranging from 10 to 80. Shock wave pressure dynamics inside the section with porous coating were studied using pressure sensors. For all mixtures, the detonation wave was formed before entering the section with porous coating. The number of pores per inch was found to significantly affect the detonation wave parameters. Non-monotonic evolution of the shock wave pressure and velocity was discovered while using porous materials with bigger pores. By the end of the porous section, the shock wave pressure in porous material with 10 pores per inch was 100% higher compared to polyurethane with 80 pores per inch. The evolution of the shock wave pressure and velocity along the porous section for different types of porous material is presented.