Initiation of spherical detonation in hydrogenair

The propagation mechanism of high speed turbulent deflagrations

“…A higher concentration of H radicals in rich mixtures facilitates the very important chain branching reaction. As weIl, it was also reported by Atkinson et al 15 that calculated induction times for rich mixtures are shorter than those for lean mixtures, which was credited to enhanced H0 2 and H202 formation on the lean side. Therefore, local quenching of the combustion…”

Regimes of Supersonic Combustion: Detonation Waves

“…In particular, in [29] critical energy values measured in experiments with H 2 + air stoichiometric were reported: E * ¼ 4.6 kJ or E * ¼ 6.3 kJ at initial temperature T 0 ¼ 298 K and pressure P 0 ¼ 0.1 MPa. The U-shaped relation between the initiation energy and the mixture [1,14,[33][34][35] dependence of the critical energy for spherical detonation initiation in H 2 + air mixtures on the equivalence ratio f. The dependence has been plotted based on data from [1,14,[33][34][35]. The data base [36] contains results of critical energy determination using a given HE charge weight and the known exothermic properties of the reaction and the initiation energy values calculated based on measured detonation cell size and the relation from [37].…”

“…A specific feature of the models is that their detonation wave is assumed to be smooth and one-dimensional. It was shown in [1][2][3] that there are correlations between some detonation parameters and the chemical induction time (ignition delay) calculated with the help of detailed chemical kinetic models. However, the detonation cell size a and the detonation wave width are in direct proportion when the induction zone length is significantly larger than the energy release area [12].…”

“…Let us use the data presented in [1][2][3]. Figure 7.1 illustrates the dependence of the detonation wave velocity D and the gas velocity u on the equivalence ratio f for the hydrogen + air mixture.…”

“…In [1,2] it was found that the induction zone length D in the ZND model is proportional to the transverse detonation cell size (width) a. The experiments revealed that the critical tube diameter for initiation is at least 13 transverse waves [30].…”