A parallel pre-cooling stamping combined propulsion system and propulsion method

Abstract

The invention discloses a parallel type precooling-stamping combined propelling system which comprises two paths of propelling devices in parallel. One path of propelling device is a strong precoolingpropelling device and comprises a first air inlet passage, an engine precooling device and a first exhaust nozzle; the other path of propelling device is a stamping propelling device and comprises asecond air inlet passage, a second fuel regulating valve, a second combustion chamber and a second exhaust nozzle; a fuel flow path outlet of the engine precooling device communicates with a fuel inlet of the second combustion chamber through a communicating pipeline; the second fuel regulating valve is arranged on the communicating pipeline; an outlet of the second combustion chamber communicateswith an inlet of the second exhaust nozzle; when the flight Mach number reaches to a first preset range value, the second fuel regulating valve is switched off, the stamping propelling device is onlyused for circulating air but does not produce a propelling force; and when the flight Mach number reaches to a second preset range value, the second fuel regulating valve is switched on, and the stamping propelling device works to produce a propelling force. The waste of fuel under high Mach number is avoided. The invention further discloses a parallel type precooling-stamping combined propellingmethod.

Description

Technical field [0001] The invention relates to the technical field of hypersonic aircraft, in particular to a parallel precooling stamping combined propulsion system and propulsion method. Background technique [0002] The military and civilian fields have an urgent need for high-speed flight, and high-speed aircraft is an important development direction in the aviation field in the future. At present, one of the main problems that plague high-speed flight is the propulsion system of the aircraft. When the aircraft is flying at hypersonic speed, the temperature of the incoming air is too high after stagnating through the intake duct, and the compressor cannot directly effectively compress the incoming air. At this time, the general Brayton cycle is no longer suitable for the aerodynamic heat of the hypersonic engine Circulation, therefore, humans try to change the aerodynamic heat circulation mode in the engine to increase the flight Mach number, thrust, specific impulse, expan...

AI Technical Summary

Problems solved by technology

When the aircraft flies at hypersonic speed, the temperature of the incoming air is too high after stagnating through the inlet, and the compressor cannot directly and effectively compress the incoming air. At this time, the general Brayton cycle is no longer suitable for the aerodynamic heat of the hypersonic engine. Therefore, human beings try to change the aerodynamic thermal cycle mode in the engine to increase the flight Mach number, thrust, specific impulse, expand its flight envelope, and pre-cooling technology has thus been used

[0003] The hydrogen / oxygen rocket engine originally designed uses low-temperature liquid hydrogen fuel to liquefy the incoming air, and then the liquid air is sent to the rocket combustion chamber through the booster pump to participate in the combustion. At a high Mach number, the intake port is closed, and the engine enters the pure rocket mode, its thrust-to-weight ratio can provide a certain power for the aircraft, but its specific impulse still does not meet the requirements of the aircraft’s single-stage orbital round-trip, and is limited by its launch mode and cannot be reused. big limitations

Afterwards, hydrogen / oxygen rocket engines were improved to some extent. The inflow deep cooling technology replaced the original inflow liquefaction technology, and hydrogen turbine expansion was used to drive the air compressor to compress the air. This solution can greatly improve the performance of the engine. Specific impulse performance, but the metal is still prone to hydrogen embrittlement under high temperature and high pressure and system safety at high temperature, which makes the precooled engine also have certain limitations

[0004] In order to solve the problem of the hydrogen / oxygen rocket engine, multiple circulation subsystems are coupled together, such as a Brayton helium cycle is set between the "hot source" air and the "cold source" liquid hydrogen, such as the SABER engine in the UK. Cold engine, but at high Mach number, the amount of hydrogen used for cooling in the strong pre-cooling propulsion system is much more than the amount used for combustion, which reduces the specific impulse of the propulsion system and causes a great waste of fuel

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