Investigation of shock wave and flame propagation induced by high pressure flammable gas within shock tube

초록

When high-pressure hydrogen is released into the air, ignition or explosion can occur due to the shock-induced heating without any ignition source, which is called self-ignition of high-pressure hydrogen. The self-ignition phenomenon is known to be mainly influenced by the shock strength with respect to the burst pressure and the length of the extension tube. In this study, a method of reducing the opening area ratio was adopted to lower the shock strength. As the area ratio decreased, the tendency of increasing the minimum burst pressure at which self-ignition occurred was confirmed, and it was proved that the small area ratio is effective in suppressing self-ignition. However, it has been found experimentally that, in the same shock strength condition, the self-ignition phenomenon is more likely to occur when the opening area ratio is small, and it is observed that a mixing between air and hydrogen could be related with the cause of this phenomenon from the numerical simulations.