Abstract
Effective fuel injection and mixing is of particular importance for scramjet engines to be operated
reliably
because the fuel must be injected into high-speed crossflow and mixed with the supersonic air at an
extremely short time-scale. This study numerically characterizes an injection jet under different
spray angles in a cold kerosene-fueled supersonic flow and thus assesses the effects of the spray
angle on the mixing between incident shock wave and transverse cavity injection. A detailed
computational fluid dynamics model is developed in accordance with the real scramjet combustor.
Next, the spray angles are designated as 45º, 90º, and 135º respectively with the other constant
operational conditions (such as the injection diameter, velocity and pressure). Next, a combination
of a three dimensional Couple Level Set & Volume of Fluids with an improved Kelvin-Helmholtz &
Rayleigh-Taylor model is used to investigate the interaction between kerosene and supersonic air.
The numerical predictions are focused on penetration depth, span expansion area, angle of shock
wave and sauter mean diameter distribution of the kerosene droplets with or without evaporation.
Finally, validation has been implemented by comparing the calculated to the measured in literature
with good qualitative agreement. Results show that no matter whether the evaporation is considered,
the penetration depth, span-wise angle and expansion area of the kerosene droplets are all
increased with the spray angle, and most especially, that the size of the kerosene droplets is
surely reduced with the spray angle increase. These calculations are beneficial to better
understand the underlying atomization mechanism in the cold kerosene-fueled supersonic flow and
hence provide
insights into scramjet design improvement.