Self-ignition of hydrogen jet due to interaction with obstacle in the obstructed space

Abstract

The paper numerically studies the process of pressurized hydrogen release through a hole or a slit into a confined space filled with air. Based on the obtained results, three basic consequences of hydrogen release are demonstrated depending on the initial pressure of hydrogen and the distance to the obstacle: (i) hydrogen ignition before the interaction of the flow with the obstacle, (ii) hydrogen ignition after the flow interaction with the obstacle, (iii) jet flow without ignition. It is shown that ignition limits are wider when hydrogen is released through the slit compared to the case of hydrogen release through a small hole. A similar effect could be achieved by changing the geometry and volume of the vessel from which hydrogen is released. Results of this study can be applicable to the elaboration of hydrogen power engineering systems dedicated either to the combustion initiation or to the suppression of ignition of non-premixed hydrogen-air mixtures.