Numerical study on detonation initiation of aviation kerosene-hydrogen-air mixtures in an obstructed tube under various hydrogen ratios and initial pressures

Aviation kerosene mixed with hydrogen provides a promising approach to improve the detonation initiation performance of aviation kerosene. In this study, the detonation initiation processes in an obstructed tube fueled with aviation kerosene/hydrogen mixtures were numerically investigated, covering hydrogen ratios from 0.1 to 0.5 and initial pressures from 0.5 atm to 2 atm. The mechanism of flame acceleration and detonation initiation was analyzed, and the effects of hydrogen ratio and initial pressure on detonation initiation were explored. The results indicated that the detonation initiation process in the obstructed tube could be divided into three stages: flame acceleration, deflagration to detonation transition (DDT), and self-sustaining detonation. The variations in detonation initiation time, detonation initiation distance, DDT run up time, DDT run up distance, the time and distance required for the DDT process under different hydrogen ratios and initial pressures were summarized. Additionally, the effects of hydrogen ratio and initial pressure on detonation velocity were also investigated.