RU2439358C2 - Air ramjet engine operating on powder metal fluid - Google Patents

Abstract

FIELD: engines and pumps.

SUBSTANCE: ramjet engine operating on metal powder fuel comprises starting system fuel feed system including fuel tank with metal powder fuel and perforated piston, and combustion chamber. Engine housing accommodates gas generator to initiate metal powder fuel feed system. Combustion chamber consists of at least 30 mm-long prechamber with dispenser arranged at its inlet to feed fuel at preset rate, igniter and final combustion chamber. Prechamber and final combustion chamber have air feed channels. Prechamber airflow allows complete suspension gasification with surplus air factor α=0.15…0.3.

EFFECT: higher heat release per unit volume due to complete combustion.

1 dwg

Description

The invention relates to an aircraft engine, and in particular to ramjet engines (ramjet) on a powdered metal fuel (PMG).

The use of metals as a fuel is due to their high activity, significant heat release and allows you to create a fundamentally new highly efficient ramjet engines for guided missiles. The advantages of ramjet engines using powdered metal fuels, using atmospheric air as an oxidizing agent, are that they provide high performance characteristics, can be used in wide speed ranges, and at the same time they are reliable in handling and storage.

Known ramjet engine for solid fuel containing a combustion chamber fed by combustible gas of the generator and atmospheric air (French patent, FR No. 2661454, IPC F02K 7/18, 1985).

The disadvantage of this engine is that at high flight speeds the completeness of fuel combustion is not ensured.

The closest in technical essence to the claimed invention is a ramjet engine selected as a prototype with a mechanical fluidized powder fuel supply system ((IPC 6 F02K 9/70, patent on PM No. 10222 of 08/17/1998), consisting of a system supply of powdered fuel, a jet turbine and a gas permeable piston.

The disadvantage of this device is the cumbersome design, including a turbine with a screw and a single combustion chamber, which does not provide the required completeness of fuel combustion.

The aim of the invention is to increase the volumetric energy output of the propulsion system by providing a more complete combustion of fuel.

The problem is solved due to the fact that a ramjet engine based on metal powder fuel is proposed, comprising an engine starting system, a fuel supply system including a fuel tank with a metal powder fuel and a perforated piston, a combustion chamber, characterized in that a gas generator is installed in the engine body ensuring the start-up of the powder metal fuel supply system, while the combustion chamber consists of a prechamber with a length of at least 300 mm, with an input dosing chamber is supplying fuel to a predetermined flow rate, igniter chamber and final reburning fuel, the pre-chamber and a final chamber afterburning have passages for feeding air.

In the first particular case of execution in the prechamber, the air flow ensures the completeness of gasification of the suspension with an excess air coefficient α = 0.15 ... 0.3.

In the second special case of execution, a reusable igniter was used to ignite the suspension.

In a third particular embodiment, granular aluminum powder can be used as a powdered fuel.

The proposed device allows to increase the volumetric energy output of the propulsion system due to the complete combustion of the metal-air mixture in the low pressure air stream.

The invention is illustrated graphic materials.

The drawing shows a diagram of a ramjet in section.

In drawing 1, the following positions are indicated:

1 - housing;

2 - gas generator;

3 - perforated piston;

4 - tank with powdered fuel;

5 - metal powder fuel;

6 - dispenser;

7, 8 - air channels;

9 - preliminary combustion chamber (prechamber);

10 - a chamber of final afterburning;

11 - igniter.

The ramjet contains a housing 1, in which a launch system (not indicated) is placed, a fuel supply system containing a gas generator 2, a displacement device in the form of a perforated piston 3, a tank 4 with metal powder 5, a dispenser 6, an air intake with exhaust air channels 7, 8, a combustion chamber (not indicated), consisting of a preliminary combustion chamber (prechamber) 9, a final afterburner 10 and a reusable igniter 11.

In the housing 1 ramjet engine components are located, ensuring its operation. Gas generator 2 to ensure the operability of the fuel supply system. The fuel supply system is a displacement and includes a perforated piston 3, permeable to gas and the formation of gas-powder suspension. For filling the tank 4, for example, aluminum can be used as the metal powder fuel 5. In this case, the dispenser 6 is made with the possibility of portioned supply of fuel. The air channels 7, 8 are part of the air intake device and are used to separate and direct the flow of atmospheric air into the prechamber 9 and the final afterburning chamber of fuel 10. At the same time, a reusable igniter 11 is installed in the prechamber. The combustion of the fuel is ensured by the fact that the combustion chamber is made in the form of a pre-chamber 9 and a final afterburner 10.

The ramjet engine 1 operates as follows. The launch accelerator is launched and informs the rocket of the required initial speed, after which the launch accelerator is detached and the gas generator 2 is simultaneously launched. 3. The flow of gases, filtered through the entire volume of powder 5, moves it to the outlet and becomes a suspension . The movement of the perforated piston 3 prevents the formation of voids, maintaining a constant dynamics of the displacement system. The regulation of the flow of powdered suspension is carried out at a constant gas pressure by changing the bore of the dispenser 6, which allows you to change the thrust of the engine over a wide range. The design of the dispenser 6 provides a low speed of metal particles and their uniform concentration in the cross section, which is confirmed experimentally, the speed of the metal particles was measured with special sensors.

In the prechamber 9, the powder 5 is mixed with the primary air stream entering the air channel 7 from the air intake, which ensures stable combustion in the low pressure air stream. The fuel mixture with the primary air stream ignites under the action of high temperature from a reusable igniter, the primary combustion of the metal-air mixture occurs. In this state, the powder suspension is saturated with oxygen obtained from atmospheric air, part of the mixture burns out, and the unburned part flows from the prechamber 9 into the final afterburner 10. The saturation of the metal powder with oxygen is characterized by an excess air coefficient α. The experiments showed that the completeness of gasification of metal-air suspension is carried out with an excess air coefficient in the range α = 0.15 ... 0.3, while the length of the prechamber 9 should be at least 300 mm. An additional portion of air enters the final combustion chamber through the duct 8, and the fuel is completely burned out. The presence of two chambers: preliminary combustion and final afterburning of fuel allows to achieve complete combustion of fuel, which significantly increases the volumetric energy output of the propulsion system. At the exit of the nozzle, gas rudders can be installed that provide thrust vector control.

The proposed device allows to increase the volumetric energy output of the propulsion system due to the complete combustion of the aluminum-air mixture in the low pressure air stream.

The implementation of these combined characteristics can significantly improve the overall dimensions and energy characteristics of a ramjet engine compared to the prototype.

The technical solution proposed for patent protection can be manufactured at enterprises producing similar products based on the production technology of already known ramjet engines. The processes taking place in ramjet engines were modeled and successfully tested in experimental propulsion systems. The experiments carried out have confirmed that the optimal size of the prechamber for complete suspension gasification is at least 300 mm, while the coefficient of excess air in the preliminary combustion chamber is in the range α = 0.15 ... 0.3.

Claims (4)

1. A ramjet engine on a metal powder fuel containing a engine start system, a fuel supply system including a fuel tank with a metal powder fuel and a perforated piston, a combustion chamber, characterized in that a gas generator is installed in the engine casing to enable the start of the powder supply system metal fuel, while the combustion chamber consists of a prechamber with a length of at least 300 mm, with a dispenser located at the inlet of the chamber supplying fuel with a given flow rate, an igniter and a chamber for final afterburning of fuel, moreover, the prechamber and the chamber of final afterburning have channels for supplying air. 2. The engine according to claim 1, characterized in that in the prechamber the air flow ensures the completeness of gasification of the suspension with an excess air coefficient α = 0.15 ... 0.3. 3. The engine according to claim 1, characterized in that a reusable igniter is used to ignite the suspension. 4. The engine according to claim 1, characterized in that granular aluminum powder can be used as a powdered fuel.