The present disclosure comprises a thrust augmentation device for liquid rocket engines that will enable higher thrust throttling when launch vehicles require the additional thrust and be turned off when the additional thrust is no longer required. The present disclosure provide a higher mission-average engine specific impulse (Isp) performance by offering a greater nozzle exit area ratio and option of MR-shift in main combustion chamber. The present disclosure retains the technology advancements made in historical rocket engine development where cost and technical challenges were great, that is in the turbopump and main injector/combustion chamber, and take advantage of engine component that is least developed and understood, the nozzle section by providing a secondary propellant injection port and combustion zone to optimize liquid rocket engine performance required by launch vehicles.

A rocket engine has a combustion chamber having an inlet and an outlet, the inlet fluidly connectable to a source of oxidizer, the outlet in fluid communication with an environment outside the combustion chamber for expelling combustion gases, a first fuel having a first solid propellant and a second fuel having a second solid propellant, the first and second fuels located within the combustion chamber and configured to be exposed to the oxidizer injected in the combustion chamber via the inlet, the first solid propellant having a regression rate greater than that of the second solid propellant.

A hybrid rocket engine system has: an oxidizer tank containing a liquid oxidizer; a rocket engine having a combustion chamber operatively connected to the oxidizer tank; a solid propellant fuel within the combustion chamber; a nozzle fluidly connected to the combustion chamber, the nozzle having a convergent section and a divergent section downstream of the convergent section; and a thrust vector control device operatively connected to the divergent section of the nozzle and operable to inject a fluid through at least one aperture defined through the divergent section for controlling a direction of a thrust generated by the rocket engine.

A hybrid rocket engine system has: an oxidizer tank containing a liquid oxidizer; a rocket engine having a combustion chamber operatively connected to the oxidizer tank; a solid propellant fuel within the combustion chamber; a nozzle fluidly connected to the combustion chamber, the nozzle having a convergent section and a divergent section downstream of the convergent section; and a thrust vector control device operatively connected to the divergent section of the nozzle and operable to inject a fluid through at least one aperture defined through the divergent section for controlling a direction of a thrust generated by the rocket engine.

A method of producing a pulsatile jet flow from a substantially constant flow primary jet in a way that is mechanically efficient, easy to implement, and allows direct control over pulse duration and pulsing frequency is disclosed herein. The invention includes at least two components: (a) a constant flow fluid jet produced by any normal method (e.g., propeller) that can be directionally vectored fluidically, mechanically, or electromagnetically and (b) a nozzle with multiple outlets (orifices) through which the vectored jet may be directed. By alternately vectoring the jet through different outlets, a transient (pulsatile) flow at an outlet is obtained even with a substantially constant primary jet flow. Additionally, the nozzle outlets may be oriented in different directions to provide thrust vectoring, making the invention useful for maneuvering, directional control, etc.

A method of producing a pulsatile jet flow from a substantially constant flow primary jet in a way that is mechanically efficient, easy to implement, and allows direct control over pulse duration and pulsing frequency is disclosed herein. The invention includes at least two components: (a) a constant flow fluid jet produced by any normal method (e.g., propeller) that can be directionally vectored fluidically, mechanically, or electromagnetically and (b) a nozzle with multiple outlets (orifices) through which the vectored jet may be directed. By alternately vectoring the jet through different outlets, a transient (pulsatile) flow at an outlet is obtained even with a substantially constant primary jet flow. Additionally, the nozzle outlets may be oriented in different directions to provide thrust vectoring, making the invention useful for maneuvering, directional control, etc.

Electrically operated propellant is used to supplement the thrust provided by solid rocket motor (SRM) propellant to manage thrust produced by a SRM. The gas produced by burning the electrically operated propellant may be injected upstream of the nozzle to add mass and increase chamber pressure Pc, injected at the throat of the nozzle to reduce the effect throat area At to increase chamber pressure Pc or injected downstream of the throat to provide thrust vector control or a combination thereof. Certain types of electrically operated propellants can be turned on and off provided the chamber pressure Pc does not exceed a self-sustaining threshold pressure eliminating the requirement for physical control valves.

Electrically operated propellant is used to supplement the thrust provided by solid rocket motor (SRM) propellant to manage thrust produced by a SRM. The gas produced by burning the electrically operated propellant may be injected upstream of the nozzle to add mass and increase chamber pressure Pc, injected at the throat of the nozzle to reduce the effect throat area At to increase chamber pressure Pc or injected downstream of the throat to provide thrust vector control or a combination thereof. Certain types of electrically operated propellants can be turned on and off provided the chamber pressure Pc does not exceed a self-sustaining threshold pressure eliminating the requirement for physical control valves.

Rocket propulsion systems and associated methods are disclosed. A representative system includes a combustion chamber having an inwardly-facing chamber wall enclosing a combustion zone. The chamber has a generally spherical shape and is exposed to the combustion zone. A propellant injector is coupled to the combustion chamber and has at least one fuel injector nozzle positioned to direct a flow of cooling fuel radially outwardly along the inwardly-facing chamber wall. In addition to or in lieu of the foregoing features, the injector can include an oxidizer piston and a fuel piston that deliver oxidizer and fuel, respectively, to the combustion chamber, in a sequenced manner so that the oxidizer is introduced prior to the fuel.

Rocket propulsion systems and associated methods are disclosed. A representative system includes a combustion chamber having an inwardly-facing chamber wall enclosing a combustion zone. The chamber has a generally spherical shape and is exposed to the combustion zone. A propellant injector is coupled to the combustion chamber and has at least one fuel injector nozzle positioned to direct a flow of cooling fuel radially outwardly along the inwardly-facing chamber wall. In addition to or in lieu of the foregoing features, the injector can include an oxidizer piston and a fuel piston that deliver oxidizer and fuel, respectively, to the combustion chamber, in a sequenced manner so that the oxidizer is introduced prior to the fuel.