CN114810430A - A low-ablation rocket engine nozzle structure and cooling method for active cooling throat lining - Google Patents

Abstract

The invention discloses a low-ablation rocket engine nozzle structure with an active cooling throat insert and a cooling method, wherein the nozzle structure comprises a nozzle body, an active cooling system and a control system; the nozzle body comprises a skirt part and a throat liner which are integrally formed along the axial direction; an annular common rail cavity is formed in the throat liner in the direction around the axis; the inner wall surface of the throat insert is provided with a plurality of air inlets connected with the common rail cavity; external low-pressure cooling air is extracted and compressed through a low-pressure air inlet pipe by an electric air pump, and high-pressure air is input into the common rail cavity through a high-pressure air outlet pipe connected with the common rail cavity to cool the throat liner; on the other hand, high-pressure air is sent into the nozzle body, a layer of cooling air film is formed on the inner wall surface of the nozzle body, the throat insert and the inner wall surface of the nozzle body are cooled, and the expansion speed of the throat diameter due to high-temperature ablation is reduced; the main nozzle structure provided by the invention can effectively ensure that the engine is in the optimal performance state for a longer time, and improve the specific impulse of the rocket engine.

Description

A low-ablation rocket engine nozzle structure and cooling method for active cooling throat lining

technical field

The invention relates to the technical field of rocket engine nozzle design, in particular to a low ablation rocket engine nozzle structure and a cooling method for actively cooling throat linings.

Background technique

The nozzle of a rocket engine is a device that converts thermal energy into kinetic energy. The size of the throat determines the working point of the rocket engine, which can control the pressure and gas flow rate of the combustion chamber, which has an important impact on the performance and safety of the engine. . The high temperature and high pressure heat flow and particle erosion in the nozzle throat during operation will cause the internal profile ablation, resulting in profile retreat and size change. The expansion of the throat diameter will eventually reduce the engine performance and reduce the engine specific impulse. The thermal insulation structure of the nozzle in the prior art mainly adopts the method of increasing the thickness of the thermal insulation layer to improve the reliability of the engine, which increases the negative mass, which is not conducive to improving the mass ratio of the engine. In addition, the patent 2020116067168 uses a web structure to guide the cooling gas into the rear of the nozzle, and at the same time compress the cooling gas through the profile, but this technology cannot control the pressure of the cooling gas in real time, and cannot improve the robustness of the system.

SUMMARY OF THE INVENTION

Purpose of the invention: In view of the problems existing in the above-mentioned background technology, the present invention provides a low-ablation rocket engine nozzle structure and cooling method that can actively cool the throat lining. The active cooling system is used to cool the throat of the nozzle. A certain thickness of air film is formed inside the diameter of the throat, which reduces the temperature of the throat lining, thereby slowing down the increase of the throat diameter. In addition, when the throat diameter becomes larger due to severe ablation of the throat, the diameter of the interface formed by the cooling gas and the hot air flow is reduced by increasing the pressure of the cooling gas, that is, the effective diameter of the throat diameter is guaranteed, and the robustness of the nozzle is improved. sex. At the same time, the cooling effect of the cooling gas film on the inner profile of the nozzle can reduce the design thickness of the thermal insulation layer of the nozzle and reduce the negative mass.

Technical scheme: In order to realize the above-mentioned purpose, the technical scheme adopted in the present invention is:

A low-ablation rocket engine nozzle structure with active cooling throat lining, comprising a nozzle body, an active cooling system and a control system; the nozzle body includes a skirt and a throat liner integrally formed along an axis direction; the throat liner is inside An annular common rail cavity is arranged around the axis; the inner wall of the throat lining is provided with a number of air intake holes connected to the common rail cavity; the active cooling system includes an electric air pump, a low-pressure air inlet pipe and a high-pressure air outlet pipe; the electric air The pump extracts and compresses the external low-pressure cooling air through the low-pressure air inlet pipe, and inputs the high-pressure gas into the common rail cavity through the high-pressure air outlet pipe connected to the common rail cavity; the control system is used to control the active cooling system to work.

Further, the electric air pump is installed on the nozzle body through a bracket; a power battery is also installed at the lower part of the nozzle body; the power battery is connected with the electric air pump through a wire.

Further, after controlling the ignition of the rocket, the control system further controls the power battery to communicate with the electric air pump to make the electric air pump work.

Further, the cold airflow is uniformly ejected from the air inlet, and the diameter of the interface between the high-temperature, high-pressure and high-speed airflow at the throat lining position during operation is the equivalent throat diameter; according to the actual nozzle ablation, the electric air pump increases Or reduce the pressure to ensure that the equivalent throat diameter is within the effective diameter range.

An active cooling method for a low-ablation rocket engine nozzle structure using the above-mentioned active cooling throat lining, comprising the following steps:

Step S1, after the control system controls the ignition of the rocket, the high-temperature and high-speed gas flows through the throat; at this time, the control system controls the power battery to communicate with the electric air pump, and the electric air pump starts to work;

Step S2, the electric air pump inhales air through the low-pressure air intake pipe, and after compression, sends the compressed gas into the common rail cavity through the high-pressure air outlet pipe, and the high-pressure air in the annular common rail cavity cools the throat lining; The air intake holes connected to the rail cavity flow into the inner wall of the throat lining, and spread to the skirt along the high-speed gas flow direction; a cooling gas film is formed along the inner surface of the entire nozzle body, which further cools the nozzle body and effectively prevents high temperature. The ablation of the inner surface of the nozzle body by the high pressure gas.

Beneficial effects:

(1) The rocket engine nozzle structure with the active cooling system provided by the present invention, by setting the annular common rail cavity, the active cooling system can perform air cooling on the throat liner with a controllable pressure and reduce the temperature of the throat liner position.

(2) The rocket engine nozzle structure with active cooling system provided by the present invention, the cooling gas of the throat is air and the airflow direction is perpendicular to the high-temperature, high-pressure and high-speed airflow, and the cooling airflow effectively reduces the particle velocity and slows down the particle to the throat. impact, while the air further oxidizes the particles, smaller particles have less effect on the throat erosion.

(3) When the throat diameter becomes larger due to severe ablation at the throat, the present invention increases the pressure of the cooling airflow by controlling the electric air pump, reduces the diameter of the interface formed by the cooling gas and the hot airflow, and ensures that the equivalent throat diameter is effectively diameter range.

It can be seen comprehensively that the low ablation rocket engine nozzle structure of the active cooling throat lining provided by the present invention can slow down the increase of the throat diameter, and at the same time, by controlling the electric air pump, the ablation throat diameter can be compensated, and the robustness of the nozzle can be improved. It can ensure the best performance of the engine for a longer time and improve the specific impulse of the rocket engine.

(4) The gas film formed in the nozzle throat lining can have a certain cooling effect on the throat lining and nozzle skirt, which improves the reliability. Under the same working conditions, a thinner nozzle insulation layer can be used to reduce the negative quality of the nozzle.

Description of drawings

Fig. 1 is the low ablation rocket engine nozzle structure schematic diagram of the active cooling throat lining provided by the present invention;

2 is a cross-sectional view of a low-ablation rocket engine nozzle structure of an active cooling throat lining provided by the present invention;

3 is a schematic diagram of the control principle of the low ablation rocket engine nozzle of the active cooling throat lining provided by the present invention;

FIG. 4 is a schematic working diagram of the low-ablation rocket engine nozzle structure of the active cooling throat liner provided by the present invention.

Description of reference numbers:

1-nozzle body; 1.1-skirt; 1.2-throat lining; 1.3-common rail cavity; 1.4-intake hole; 2-active cooling system; 2.1-electric air pump; 2.2-low pressure intake pipe; 2.3-high pressure Outlet pipe; 2.4-bracket; 3-power battery; 3.1-wire; 4-control system; 5-rocket ignition; 6-cooling film; 6.1-cooling gas direction; 7-high-speed, high-temperature and high-pressure airflow; 7.1-hot airflow particle Airflow direction.

Detailed ways

A specific embodiment is provided below in conjunction with the accompanying drawings to further illustrate the present invention.

The structure of the low ablation rocket engine nozzle provided by the present invention that can actively cool the throat lining is shown in FIG. The nozzle body 1 includes a truncated truncated skirt 1.1 and a cylindrical throat liner 1.2 integrally formed along the axial direction. An annular common rail cavity 1.3 is provided inside the throat liner 1.2 around the axis. The inner wall of the throat liner 1.2 is provided with a number of air inlet holes 1.4 connected with the common rail cavity 1.3. In particular, in this embodiment, both the skirt and the throat lining are made of ablation-resistant structures.

The active cooling system 2 includes an electric air pump 2.1, a low-pressure air intake pipe 2.2, a high-pressure air outlet pipe 2.3 and a bracket 2.4. The electric air pump 2.1 is arranged on the upper end of the nozzle body 1, and is installed and fixed by the bracket 2.4. The electric air pump 2.1 has a low-pressure air intake pipe 2.2 extending from the outside, and the external low-pressure cooling air is extracted through the low-pressure intake pipe 2.2 and compressed, and the high-pressure gas is fed into the common rail cavity 1.3 through the high-pressure air outlet pipe 2.3 connected to the common rail cavity 1.3, as shown in picture 2.

The electric air pump controls the air inlet to spray out cold air evenly, and the diameter of the interface with the high temperature, high pressure and high speed air flow at the throat lining position during operation is the equivalent throat diameter; according to the actual nozzle ablation, the electric air pump can increase or decrease it. Small pressure can ensure that the equivalent throat diameter is within the effective diameter range.

The power battery 3 is fixedly installed at the lower part of the nozzle body 1, and the electric air pump 2.1 is connected together through the wire 3.1 to supply power to the electric air pump 2.1.

The low-ablation rocket engine nozzle structure control method of the active cooling throat lining provided by the present invention is shown in FIG. 3 . After the control system 4 controls the rocket ignition 5 to work, it controls the power battery 3 to be connected with the electric air pump 2.1 circuit, and then controls the electric air Pump 2.1 works normally. The electric air pump 2.1 pressurizes the air sucked from the low-pressure air intake pipe 2.2, and sends the high-pressure air into the common rail cavity 1.3 through the high-pressure air outlet pipe 2.3. The high-pressure air in the high-pressure common rail cavity 1.3 cools the throat lining 1.2, At the same time, the high-pressure air is sent into the nozzle body 1 through the air inlet 1.4 on the throat lining 1.2. Under the action of the high-speed, high-temperature and high-pressure airflow 7 on the inner wall of the nozzle body 1, a layer of cooling is formed on the inner surface of the nozzle body 1. The gas film 6 cools the throat lining 1.2 and the inner wall surface of the nozzle body 1 to reduce the expansion speed of the throat diameter due to high temperature ablation, as shown in FIG. 4 .

Among them, the cooling air of the throat lining 1.2 is air and the cooling air direction 6.1 is perpendicular to the hot air particle direction 7.1. The airflow reduces the particle velocity and slows down the impact of the particles on the throat lining 1.2. At the same time, the air further oxidizes the particles, and the smaller the The particles have less erosion effect on the throat lining 1.2.

In addition, when the throat lining 1.2 is severely ablated and the throat diameter becomes larger, the control system 4 increases the pressure of the cooling gas by controlling the electric air pump 1.2, reduces the diameter of the interface formed by the cooling gas and the hot air flow, and ensures that the equivalent throat diameter is always Maintaining within the effective throat diameter range can slow down the increase in throat diameter. At the same time, the ablation throat diameter can be compensated by controlling the electric air pump, which can significantly improve the robustness of the nozzle and effectively ensure that the engine is in the best performance state for a longer time. , which increases the specific impulse of the rocket engine. The cooling effect of the cooling gas film on the inner profile of the nozzle can reduce the design thickness of the thermal insulation layer of the nozzle and reduce the negative mass.

The above is only the preferred embodiment of the present invention, it should be pointed out that: for those skilled in the art, without departing from the principle of the present invention, several improvements and modifications can also be made, and these improvements and modifications are also It should be regarded as the protection scope of the present invention.

Claims (5)

1. A low ablation rocket engine nozzle structure of an active cooling throat insert is characterized by comprising a nozzle body, an active cooling system and a control system; the nozzle body comprises a skirt part and a throat liner which are integrally formed along the axial direction; an annular common rail cavity is formed in the throat liner along the direction of an axis; the inner wall surface of the throat insert is provided with a plurality of air inlets connected with the common rail cavity; the active cooling system comprises an electric air pump, a low-pressure air inlet pipe and a high-pressure air outlet pipe; the electric air pump extracts external low-pressure cooling air through a low-pressure air inlet pipe and compresses the air, and high-pressure air is input into the common rail cavity through a high-pressure air outlet pipe connected with the common rail cavity; the control system is used for controlling the active cooling system to work.

2. The actively-cooled throat insert low ablation rocket engine nozzle structure as claimed in claim 1 wherein said electric air pump is mounted on the nozzle body by a bracket; the lower part of the spray pipe body is also provided with a power battery; and the power battery is connected with the electric air pump through a lead.

3. The low ablation rocket engine nozzle structure of active cooling throat insert of claim 1 wherein said control system further controls the power battery to communicate with the electric air pump to operate the electric air pump after controlling rocket ignition.

4. The low ablation rocket engine nozzle structure of claim 3 wherein the cold air flow is ejected uniformly from the inlet orifice, and the diameter of the interface between the cold air flow and the high temperature, high pressure and high velocity air flow at the throat insert position during operation is the equivalent throat diameter; according to the actual nozzle ablation condition, the pressure is increased or reduced through the electric air pump, and the equivalent throat diameter can be ensured to be in the effective diameter range.

5. A method of actively cooling a low ablation rocket engine nozzle structure based on an actively cooled throat insert according to any one of claims 1-4, comprising the steps of:

step S1, after the control system controls the rocket to ignite, high-temperature and high-pressure high-speed gas flows through the throat; at the moment, the control system controls the power battery to be communicated with the electric air pump, and the electric air pump starts to work;

step S2, the electric air pump sucks air through the low-pressure air inlet pipe, after compression, the compressed air is sent into the common rail cavity through the high-pressure air outlet pipe, and the throat liner is cooled by the high-pressure air in the annular common rail cavity; high-pressure air flows into the inner wall surface of the throat insert through an air inlet connected with the common rail cavity and is diffused to the skirt part along the flow direction of high-speed air; a layer of cooling air film is formed along the inner profile of the whole spray pipe body, the spray pipe body is further cooled, and ablation of high-temperature and high-pressure air on the inner profile of the spray pipe body is prevented;

and step S3, when the actual throat diameter is increased due to ablation of the throat liner, the control system controls the electric air pump to increase the pressure of the cooling air flow, reduce the equivalent throat diameter, ensure that the equivalent throat diameter is always maintained in the range of the effective throat diameter, and slow down the increase of the throat diameter.

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