Injection device, combustor, and rocket engine

An injection device comprising:

• a device main body partitioned into a fuel manifold and an oxidant manifold;
• and
• a plurality of injectors arranged at predetermined intervals in the device main body and inject fuel and oxidant into a combustion chamber, wherein
• the plurality of injectors each includes
• an oxidant channel including a proximal end portion communicating with the oxidant manifold and a distal end portion communicating with the combustion chamber,
• a restrictor provided on the proximal end portion of the oxidant channel, and
• a fuel channel including a proximal end portion communicating with the fuel manifold and a distal end portion communicating with the combustion chamber,
• the restrictors in the plurality of injectors have different shapes,
• shapes of the restrictors in the plurality of injectors are set different in accordance with a pressure oscillation mode occurring in the combustion chamber, and
• the shapes of the restrictors are set to amplify pressure oscillation of a preset certain frequency, and the combustion chamber communicates with a resonator configured to attenuate the pressure oscillation of the certain frequency.