Numerical Study of Hydrogen Injection to initiate Oblique Detonation Wave

The current study is motivated to develop strategies for hydrogen injection in high-speed air stream, at upstream of finite length wedge of oblique detonation wave combustor using numerical simulations. The unsteady two-dimensional Navier-Stokes equations with reactive multi-species along with turbulence modelling are solved for the oblique shock wave (OSW) to oblique detonation wave (ODW) transition for hydrogen injection into high-speed air with wedge at angle θ = 220 for incoming air flow velocity of 2400-3400 m/s and pressure of 63 kPa and temperature of 300 K. Initially, premixed hydrogen-air mixture with above freestream speed and pressure and temperature is simulated for given wedge angle to establish oblique detonation wave as reference case. Further, equivalent cases with upstream hydrogen injection (subsonic/supersonic) are simulated with different fuel flow rate to establish shock induced combustion and oblique detonation wave on the finite length 10 cm of wedge length. The transition of oblique shock to oblique detonation wave depends on efficiency of mixing near the vicinity of wedge. The results are discussed with quantification of effective injection length as well as injected mass flow rate to establish the oblique detonation wave.