The inventors introduce the Borissov-Markusic Cycle as the new rocket engine cycle to solve the problem of low efficient open gas generator or tap-off gas generator cycles used to supply power to turbopump. A liquid rocket engine directs turbopump exhaust from a turbopump to a booster engine having an intake to accept ambient airflow, such as a variation of a ramjet, scramjet or dual mode ram scramjet engine. The turbopump is powered by combustion gases, such as from a gas generator or a tap-off manifold interfaced with the liquid rocket engine combustion chamber, and applies energy of the combustion gases to pump fuel and/or liquid oxygen to the liquid rocket engine combustion chamber. The combustion gases have a fuel-rich composition that includes unconsumed fuel from incomplete oxidation so that, upon injection into the combustion chamber of the booster engine, oxidation by ambient air of the unconsumed fuel releases energy to generate thrust with the booster engine.

The inventors introduce the Borissov-Markusic Cycle as the new rocket engine cycle to solve the problem of low efficient open gas generator or tap-off gas generator cycles used to supply power to turbopump. A liquid rocket engine directs turbopump exhaust from a turbopump to a booster engine having an intake to accept ambient airflow, such as a variation of a ramjet, scramjet or dual mode ram scramjet engine. The turbopump is powered by combustion gases, such as from a gas generator or a tap-off manifold interfaced with the liquid rocket engine combustion chamber, and applies energy of the combustion gases to pump fuel and/or liquid oxygen to the liquid rocket engine combustion chamber. The combustion gases have a fuel-rich composition that includes unconsumed fuel from incomplete oxidation so that, upon injection into the combustion chamber of the booster engine, oxidation by ambient air of the unconsumed fuel releases energy to generate thrust with the booster engine.

A rocket in one example includes separate chambers for storing two thrust grains: an initial thrust grain and a boost thrust grain. The initial thrust grain is stored in a first chamber and the boost thrust grain is stored in a second chamber. The initial thrust grain is ignited separately from the boost thrust grain, such as in a two-stage process where the initial thrust grain is ignited before, or at the same time as, the boost thrust grain. The initial thrust grain has a large surface area (different burn pattern) relative to the boost thrust grain, which causes the initial thrust grain to have a shorter burn time than the boost thrust grain.

An air-breathing rocket engine in certain embodiments comprises an hourglass-shaped outer shell and an interior portion situated entirely within the front end of the outer shell. The interior portion includes a funnel-shaped intake that terminates in a floor and an inner front wall that forms a first circumferential gap between the inner front wall and the outer surface of the funnel-shaped intake. The intake has a central aperture that is in fluid communication with the throat and exhaust areas within the outer shell. A second circumferential gap is formed between the outer surface of the front inner wall and the inner surface of the front end of the outer shell and is in fluid communication with the throat and exhaust areas within the outer shell. One or more injector polis and one or more ignition ports are situated at the front end of the second circumferential gap.

An air-breathing rocket engine in certain embodiments comprises an hourglass-shaped outer shell and an interior portion situated entirely within the front end of the outer shell. The interior portion includes a funnel-shaped intake that terminates in a floor and an inner front wall that forms a first circumferential gap between the inner front wall and the outer surface of the funnel-shaped intake. The intake has a central aperture that is in fluid communication with the throat and exhaust areas within the outer shell. A second circumferential gap is formed between the outer surface of the front inner wall and the inner surface of the front end of the outer shell and is in fluid communication with the throat and exhaust areas within the outer shell. One or more injector polis and one or more ignition ports are situated at the front end of the second circumferential gap.

The jet engine comprising a ramjet air path extending from an intake, into a combustion chamber, and out an exhaust nozzle, a fuel inlet leading into the combustion chamber, an oxidizer inlet leading into the combustion chamber and a partition being operable to selectively close the ramjet air path upstream of the combustion chamber to allow operation of the jet engine in rocket mode and open the ramjet air path to allow operation of the jet engine in ramjet mode.

The jet engine comprising a ramjet air path extending from an intake, into a combustion chamber, and out an exhaust nozzle, a fuel inlet leading into the combustion chamber, an oxidizer inlet leading into the combustion chamber and a partition being operable to selectively close the ramjet air path upstream of the combustion chamber to allow operation of the jet engine in rocket mode and open the ramjet air path to allow operation of the jet engine in ramjet mode.

Described is a propulsion system (1) for hypersonic aircraft, having an air inlet (10) of a fluid (110), a containment duct (20) and an exhaust nozzle (30). The propulsion system (1) comprises a bypass duct (40) for a flow (100) of fluid (110), an air-breathing engine (22) and a rocket (23) configured for processing respective flows (22a, 23a) of fluid (110). The bypass duct (40), the air-breathing engine (22) and the rocket (23) are operatively associated with each other in such a way as to generate a thermodynamic-fluid interaction in a same portion of space (33) between the respective flows (40a, 22a, 23a) processed in an operating configuration of the propulsion system (1) and wherein the portion of space (33) is inside the containment duct (20).

Described is a propulsion system (1) for hypersonic aircraft, having an air inlet (10) of a fluid (110), a containment duct (20) and an exhaust nozzle (30). The propulsion system (1) comprises a bypass duct (40) for a flow (100) of fluid (110), an air-breathing engine (22) and a rocket (23) configured for processing respective flows (22a, 23a) of fluid (110). The bypass duct (40), the air-breathing engine (22) and the rocket (23) are operatively associated with each other in such a way as to generate a thermodynamic-fluid interaction in a same portion of space (33) between the respective flows (40a, 22a, 23a) processed in an operating configuration of the propulsion system (1) and wherein the portion of space (33) is inside the containment duct (20).

An air-breathing rocket engine with an hourglass-shaped outer shell and an interior portion situated entirely within the front end of the outer shell. The interior portion includes a funnel-shaped intake that terminates in a floor and an inner front wall that forms a first circumferential gap between the inner front wall and the outer surface of the funnel-shaped intake. The intake has a central aperture that is in fluid communication with the throat and exhaust areas within the outer shell. A second circumferential gap is formed between the outer surface of the front inner wall and the inner surface of the front end of the outer shell and is in fluid communication with the throat and exhaust areas within the outer shell. One or more injector ports and one or more ignition ports are situated at the front end of the second circumferential gap.