Low Mach Number Testing of a Scramjet for Access to Space

摘要

Experiments with a scramjet engine fur a planned Mach 5-10 access-to-space vehicle have been undertaken in the T4 reflected shock tunnel at low Mach number conditions. The 3D scramjet flow path is designed to integrate with a conical vehicle and involves significant shape transition to enhance aerodynamic efficiency. Gaseous hydrogen is used as the fuel, injected at multiple locations through the engine. A generic thrust nozzle is included downstream of the diverging section of the combustor. Distributed injection is shown to be effective at a Mach 7 flight condition with a nominal dynamic pressure of 55 kPa. For an increased dynamic pressure of 130 kPa, robust separated combustion is observed at lower total equivalence ratios and without the need for distributed injection. At a simulated Mach 6 flight condition, no ignition is observed at 55 kPa while robust combustion occurs at the high pressure condition. These experiments utilised a flowpath which was altered from an operational flight design to fit within the tunnel core flow. Hence, the experiments are exploratory in nature rather than demonstrating the performance of an operational engine.