Numerical Investigation on Effects of Equivalence Ratio on Two-phase Detonation Wave Formation

Deflagration to Detonation Transition (DDT) phenomena of liquid fuel octane droplets in air in detonation tube are simulated here. The numerical formulation is described, on which code-CPTD is developed. Basic properties of liquid-fueled detonation structure together with the effects of partial preevaporation and droplet amount on detonation structure and development are investigated in current study. Simulations reveal that the presence of some amount of initial fuel vapor in the tube will substantially expedite transition to detonation, on the other hand, the existence of some fuel droplets may exhibit a suppression to detonation wave, and increasing amount or concentration of fuel droplets will delay deflagration to detonation transition. The calculations show that the numerical results are in good agreement with experimental ones, which implies that a feasible numerical method has been provided here to simulate pulse detonation engine operation processes including DDT phenomena.