fig4

Figure 4. Hydrogen ignition and explosion. (A) MIE of H₂, CH₄ and C₃H₈ in air. Reproduced with permission^[67], Copyright 2023, Springer Fachmedien Wiesbaden GmbH. (B) Schematic of hydrogen self-ignition within a tube, depicted from top to bottom: the setup prior to rupture; the initial formation of a shockwave; the creation of vortex rings and reactions in both the core and boundary layer regions, triggered by interactions between shockwaves and the boundary layer; reactions occurring primarily in the core region; and the eventual merging of the two reactive zones. Reproduced with permission^[69], Copyright 2010, The Combustion Institute. Published by Elsevier Inc. (C) Time histories of overpressure from ignition experiments with 29.3% hydrogen concentrations. Reproduced with permission^[95], Copyright 2012, Elsevier Ltd. (D) High-speed images from hydrogen-air cloud detonation test. Reproduced with permission^[98], Copyright 2007, Elsevier Ltd. (E) Temperature contours, Schlieren images, and pressure contours capture the final stage of DDT in an uneven H₂/Air mixture with a 20% concentration. Reproduced with permission^[100], Copyright 2022, Elsevier Ltd.