Numerical Simulation of the Influence of Hydrogen Concentration on Detonation Diffraction Mechanism

In this study, the impact of hydrogen concentration on deflagration to detonation transition (DDT) and diffraction mechanisms was investigated. The combustion chamber an ENACCEF facility, with nine obstacles at a blockage ratio 0.63 three mixtures concentrations 13%, 20%, 30%. Detonation were numerically investigated by density-based solver OpenFOAM CFD toolbox named ddtFoam. simulation, for low Mach numbers, pddtFoam applied, high speeds, switched ddtFoam simulate flame propagation without resolving all microscopic details in flow grid, provide basis simulating acceleration (FA) onset large three-dimensional geometries. results showed that, lean H2–air mixture 13% concentration, intense interaction between propagating turbulent led rapid from slow fast deflagration. However, did not occur inside tube. For 20% initiation appeared It also found that following detonation, collision transverse waves wall tube reflection most essential effective parameters re-initiation detonation. 30% occurred while passing through obstacles. Subsequently, diffraction, direct mechanism observed.