Thrust augmentation of an additively manufactured hybrid rocket system using secondary oxidizer injection

A hybrid rocket, comprising:

• a housing having a first end and a second end;
• a solid-grain fuel material positioned in the housing and defining a bore that extends from the first end to the second end, the bore in the solid-grain fuel material defining an internal surface of the solid-grain fuel material exposed within the housing;
• at least two electrodes positioned adjacent to the solid-grain fuel material and extending through the housing to the internal surface of the solid-grain fuel material to ignite the solid-grain fuel material at the first end;
• a primary oxidizer port positioned at the first end to inject a primary oxidizer to flow in a downstream direction from the first end to the second end;
• a nozzle positioned at the second end and having a converging portion and a diverging portion;
• an additive oxidizer port to inject an additive oxidizer downstream of the converging portion, the additive oxidizer comprising at least 85% H2O2;
• wherein:
• the bore has a geometry configured to produce a hot-gas, fuel-rich mixture at the nozzle as the solid grain fuel material and the primary oxidizer burn while flowing downstream, and
• the diverging portion is configured to spontaneously combust the additive oxidizer and the hot-gas, fuel-rich mixture.

A method of augmenting combustion in a hybrid rocket, comprising:

• providing a housing having a first end and a second end, a solid-grain fuel material positioned in the housing and defining a bore that extends from the first end to the second end, the bore in the solid-grain fuel material defining an internal surface of the solid-grain fuel material exposed within the housing, at least two electrodes positioned adjacent to the solid-grain fuel material and extending through the housing to the internal surface of the solid-grain fuel material at the first end, a nozzle positioned at the second end and having a converging portion and a diverging portion, a primary oxidizer port positioned at the first end, and a secondary oxidizer port positioned downstream of the converging portion;
• delivering a primary oxidizer into the bore at the primary oxidizer port;
• igniting the solid-grain fuel material at the first end with the at least two electrodes;
• delivering a hot-gas, fuel-rich mixture to the nozzle through the bore, the bore has a geometry configured to produce the hot-gas, fuel-rich mixture at the nozzle as the solid-grain fuel material and the primary oxidizer burn while flowing downstream;
• delivering a secondary oxidizer through the secondary oxidizer port to spontaneously combust the additive oxidizer and the hot-gas, fuel-rich mixture in the diverging portion.