Scramjet engine and flying object

A scramjet engine comprising:

• a first flow path forming member;
• a second flow path forming member provided opposite to the first flow path forming member;
• a first fuel injection device;
• and
• a second fuel injection device,
• wherein a flow path is formed between the first flow path forming member and the second flow path forming member,
• wherein the flow path includes:
• a turbulence formation region to which compressed air is introduced from upstream;
• and
• a combustion region that is located downstream of the turbulence formation region and where combustion using the compressed air is carried out,
• wherein the second flow path forming member comprises at least one protrusion located in the turbulence formation region, the at least one protrusion protruding toward the first flow path forming member,
• wherein the first fuel injection device is configured to inject first fuel into the compressed air via a first fuel nozzle provided on the at least one protrusion,
• wherein the second flow path forming member is formed with a cavity located in the combustion region,
• wherein the second fuel injection device is configured to inject second fuel into the compressed air via a second fuel nozzle provided to the cavity,
• wherein the cavity comprises:
• a bottom surface;
• and
• an inclined surface connected to a downstream side end of the bottom surface,
• wherein an inclination of the inclined surface of the cavity is configured to be adjusted such that a shock wave is generated in the combustion region to generate a discontinuity surface that reaches inside the cavity, and
• wherein the second fuel nozzle is configured to inject the second fuel from a location proximate the bottom surface of the cavity and downstream of the discontinuity surface such that:
• (i) the second fuel is injected with an upstream axial component into an upstream flowing portion of cavity recirculation flow;
• and (ii) the second fuel crosses the discontinuity surface in the cavity to join the cavity recirculation flow.