Comparison of Hypermixer Geometries in an Axisymmetric Supersonic Combustion Flowpath

The combustion characteristics of shock-enhanced mixing devices were studied in an axisymmetric Mach 2.6 combustion flowpath. Tapered, wall-mounted wedges were placed downstream of transverse fuel injection for mixing enhancement. Otherwise identical wedges featuring castellations cut into the tapered wedge geometry were investigated for additional enhancement of streamwise vorticity. Wall pressure measurements, pitot measurements, and high-speed images were recorded to establish a comparison between the geometries for ram- mode combustion. Results revealed the ability of the plain wedge to autoignite the flow, whereas the flowpath was incapable of autoignition without augmentation. The castellated wedge further enhanced flameholding stability, providing an experimental example of a classical "hypermixer" adapted to an axisymmetric geometry.