Tailored fuel injection for performance enhancement in a Mach 12 scramjet engine

To investigate the potential performance benefits of tailored fuel injection in a scramjet engine, flow through a rectangular-to-elliptical shape-transitioning scramjet was simulated with two different combustor injection geometries: one with uniformly-spaced boundary-layer fuel injection, and the other with oblique-angle porthole injectors targeting the flow structures observed in engine simulations. Both engines utilized inlet injection to promote rapid ignition and burning of the combustor-injected fuel. The simulations were compared with experimental data for validation purposes. The tailored-injection engine fueled to an equivalence ratio of 1.24 was found to have superior mixing and combustion efficiencies, improving upon the 1.33 equivalence ratio symmetric engine by 7% and 2%, respectively. Tailored injection was shown to be a promising method for improving scramjet performance, potentially allowing higher fuel efficiency and a shorter combustor section