Self-ignition in high-pressure hydrogen jets may take place when transverse shock waves are generated from diaphragm transformation. In this study, a numerical analysis was performed to find out the mechanism of self-ignition in a high-pressure hydrogen jet in a tube. High-pressure hydrogen and air at the atmospheric pressure were mixed to yield vortices in the boundary layer and at the contact surface. The high temperature and high-pressure atmosphere in the mixing region, and the generation of a precursor shock wave following the flow of hydrogen under such high-pressure conditions, caused self-ignition. A numerical simulation showed that the ignition happens within the vortices in the tube.
self-ignition, hydrogen, shock wave, contact surface, transverse wave