Effects of mixture initial conditions on deflagration to detonation transition enhanced by transverse jets

To explore the effects of mixture initial conditions on the deflagration to detonation transition (DDT) enhanced by transverse jets, numerical studies were conducted on the flame acceleration of H2/Air mixture under different initial conditions, including initial pressure, temperature, and equivalence ratio. The results indicate significant differences in flame acceleration processes under different initial pressures (0.05, 0.1, 0.15, and 0.2 MPa). Changes in jet intensity and combustion rate induced by variations in mixture initial pressure collectively influence the flame acceleration process, but the impact of jet intensity is more significant. However, effective coupling between transverse wave propagation and flame acceleration is also crucial for the DDT process. Changes in mixture initial temperature (300, 350, 400, and 450 K) and equivalence ratio (0.8, 1.0, 1.2, and 1.4) have negligible impact on jet intensity. The variation trend of flame velocity under different initial temperatures or equivalence ratios is consistent, but the detonation initiation performance is slightly different. As the initial temperature increases, the DDT distance and DDT time are shortened. With an increasing equivalence ratio, the DDT distance and DDT time initially decrease and then increase, reaching the shortest at slightly rich fuel conditions.