Mixing augmentation induced by the interaction between the oblique shock wave and a sonic hydrogen jet in supersonic flows

• Interaction between oblique shock wave and hydrogen jet was investigated numerically.
• Influences of wedge angle and jet-to-crossflow pressure ratio were evaluated.
• Oblique shock wave has a great impact on the mixing augmentation in supersonic flows.
• There exists a critical value for wedge angle irrespective of jet-to-crossflow pressure ratio.

The mixing process between the injectant and air is very important for the operation of scramjet engine, and the injectant and air should be mixed sufficiently before entering into the combustor. The three-dimensional Reynolds-average Navier–Stokes equations coupled with the SST k–ω turbulence model have been employed to investigate the interaction of the oblique shock wave and the hydrogen jet, and the influence of the wedge angle has been taken into consideration, namely the intensity of the produced oblique shock wave, as well as the jet-to-crossflow pressure ratio. In this paper, the produced oblique shock wave collides with the bottom wall upstream and downstream of the jet orifice with the variance of the wedge angle. The obtained results show that the incident shock wave makes a great difference to the mixing enhancement between the injectant and air, and there exists a critical value of the wedge angle for the scramjet engine with a certain boundary condition. This value is 20° in the range considered in the current study, and the hydrogen is brought into the separation zone upstream of the jet orifice when the wedge angle is 20°. At the same time, the produced oblique shock wave nearly collides with the Mach disk produced by the hydrogen jet.