阅读说明：本技术 一种用于火箭发动机的可控式开槽喷管 (Controllable slotted spray pipe for rocket engine ) 是由 于海旭 魏志军 于 2021-08-20 设计创作，主要内容包括：本发明公开的一种用于火箭发动机的可控式开槽喷管,属于火箭发动机技术领域。本发明包括开槽喷管、通气槽控制装置；所述开槽喷管在喷管扩张段,沿轴线方向开有若干组通气槽,同一组内的若干个尺寸一致的通气槽沿周向均匀分布；每个上述通气槽外侧都配有与之匹配的通气槽控制装置；通过通气槽控制装置控制通气槽开启或关闭；通气槽均开启时,通过控制喷管内部的流动分离来有效提高喷管在低空工况下的性能,起到高度补偿的作用；通过不对称控制一组或多组通气槽的开启或关闭状态,引起喷管内流动的不对称,达到推力矢量控制的目的。本发明能够显著提高火箭发动机的喷管效率,有效提高喷管在低空工况下的性能,且能够提高喷管的结构稳定性及火箭入轨精度。(The invention discloses a controllable slotted spray pipe for a rocket engine, and belongs to the technical field of rocket engines. The invention comprises a slotted spray pipe and a vent groove control device; the slotted spray pipe is provided with a plurality of groups of vent grooves in the expansion section of the spray pipe along the axial direction, and a plurality of vent grooves with the same size in the same group are uniformly distributed along the circumferential direction; the outer side of each vent groove is provided with a vent groove control device matched with the vent groove; the opening or closing of the vent groove is controlled by a vent groove control device; when the vent grooves are all opened, the performance of the spray pipe under the low-altitude working condition is effectively improved by controlling the flow separation in the spray pipe, and the height compensation effect is achieved; the opening or closing state of one or more groups of vent grooves is asymmetrically controlled to cause the asymmetry of the flow in the spray pipe, thereby achieving the purpose of thrust vector control. The invention can obviously improve the efficiency of the jet pipe of the rocket engine, effectively improve the performance of the jet pipe under the low-altitude working condition, and improve the structural stability of the jet pipe and the orbit entering precision of the rocket.)

1. A controllable formula fluting spray tube for rocket engine which characterized in that: comprises a slotted spray pipe (1) and a vent groove control device (2);

the slotted spray pipe (1) is provided with a plurality of groups of vent grooves in the expansion section of the spray pipe along the axial direction, and a plurality of vent grooves with the same size in the same group are uniformly distributed along the circumferential direction;

the outer side of each vent groove is provided with a vent groove control device (2) matched with the vent groove;

the opening or closing of the vent groove is controlled by a vent groove control device (2);

when the vent grooves are all opened, the performance of the spray pipe under the low-altitude working condition is effectively improved by controlling the flow separation in the spray pipe, and the height compensation effect is achieved;

the opening or closing state of one or more groups of vent grooves is asymmetrically controlled to cause the asymmetry of the flow in the spray pipe, thereby achieving the purpose of thrust vector control.

2. A controllable slotted nozzle for a rocket engine as recited in claim 1, wherein: each ventilation groove control device (2) comprises a fixed seat (21), an actuating cylinder (23), a connecting piece (24) and a cover plate (25); the actuating cylinder (23) is used for realizing the feeding and resetting movement along the axial direction; the actuating cylinder (23) is connected with the fixed seat (21) through a rotating shaft (22), the rotating shaft (22) is driven by the motor to rotate within a certain angle, and the actuating cylinder (23) controls the position of the cover plate (25) so as to control the opening or closing of the vent groove.

3. A controllable slotted nozzle for a rocket engine as defined in claim 1 or 2, wherein: in order to realize thrust vector control, the number of each group of vent grooves is not less than three.

4. A controllable slotted nozzle for a rocket engine as defined in claim 1 or 2, wherein: according to the performance requirement and the size change, the corresponding performance requirement is realized by changing the number of the groups of the vent grooves, the number of each group of the grooves and the axial position of each group of the grooves; the respective performance requirements include a height compensation effect and a thrust vector control requirement.

5. A controllable slotted nozzle for a rocket engine as defined in claim 1 or 2, wherein: the working method is that the engine is ignited on the ground and starts to work, at the moment, the spray pipe is in an initial state, all vent grooves are opened, outside ambient air enters the interior of the spray pipe through the vent grooves and disturbs the internal flow, so that the flow separation in the spray pipe is controlled, the pressure distribution of the inner wall surface of the spray pipe behind the flow separation point is improved, the thrust is larger than that of a conventional spray pipe, and the height compensation effect is achieved;

when the flying height of the rocket is increased and reaches a first preset height, the first group of vent grooves (11) are closed, so that the gas is prevented from leaking to the environment through the first group of vent grooves (11); the flying height continues to increase, and when a second preset height is reached, the second group of ventilation slots (12) are closed; and so on until all vent grooves are closed;

at any flying height, the opening or closing state of one or more groups of vent grooves is asymmetrically controlled to cause the asymmetry of the flow in the spray pipe, thereby achieving the purpose of thrust vector control.

Technical Field

The invention relates to a controllable slotted spray pipe for a rocket engine, and belongs to the technical field of rocket engines.

Background

The nozzle is one of the important components of the rocket engine. With conventional rocket nozzles, the operating conditions typically go through three phases: when the rocket takes off, the pressure of the external environment is higher than the pressure of the outlet of the spray pipe, and the spray pipe works in an over-expansion state; when the rocket flies to a certain height, the external environment pressure is equal to the outlet pressure of the spray pipe, and the spray pipe works in a designed state; and the pressure of the external environment is lower than the pressure of the outlet of the spray pipe along with the continuous lifting of the flying height of the rocket, and the spray pipe works in an under-expansion state. When the spray pipe works in a design state, the efficiency is highest, the ideal spray pipe is that the outlet area of the spray pipe can continuously change along with the flying height of the rocket, so that the outlet pressure of the spray pipe is always equal to the environmental pressure, the spray pipe works in the design state all the time, but the spray pipe structure is difficult to realize in the prior engineering.

When the nozzle is operated in a non-design state, non-adaptive loss occurs, and the efficiency of the nozzle is reduced. Particularly, when the nozzle is in an over-expansion state, the high back pressure often causes an unsteady and asymmetric complex wave system to appear in the nozzle, so that a lateral force and even a serious fluid-solid coupling phenomenon are caused, and the structural stability of the nozzle and the orbit entering precision of the rocket are endangered. Therefore, in order to avoid the influence of the flow separation phenomenon in the over-expanded state of the nozzle on the reliability of the engine, the nozzle expansion ratio has to be designed to be small, thereby causing a problem that the nozzle is operated in the under-expanded state for a long time, causing a great loss of performance.

Disclosure of Invention

The invention aims to provide a controllable slotted spray pipe for a rocket engine, which can effectively improve the performance of the spray pipe under a low-altitude working condition by controlling the flow separation in the spray pipe, plays a role in height compensation and can achieve the purpose of thrust vector control.

The purpose of the invention is realized by the following technical scheme:

the invention discloses a controllable slotted spray pipe for a rocket engine, which comprises a slotted spray pipe and a vent groove control device.

The slotted spray pipe is provided with a plurality of groups of vent grooves in the expansion section of the spray pipe along the axis direction, and a plurality of vent grooves with the same size in the same group are uniformly distributed along the circumferential direction.

And the outer side of each air channel is provided with an air channel control device matched with the air channel.

The opening or closing of the vent groove is controlled by a vent groove control device;

when the vent grooves are all opened, the performance of the spray pipe under the low-altitude working condition is effectively improved by controlling the flow separation in the spray pipe, and the height compensation effect is achieved;

the opening or closing state of one or more groups of vent grooves is asymmetrically controlled to cause the asymmetry of the flow in the spray pipe, thereby achieving the purpose of thrust vector control.

Preferably, each of the vent groove control devices includes a fixing base, an actuating cylinder, a connecting member and a cover plate. The actuating cylinder is used for realizing the feeding and resetting movement along the axial direction. The actuating cylinder is connected with the fixed seat through a rotating shaft, the rotating shaft is driven by the motor to rotate within a certain angle, and the actuating cylinder controls the position of the cover plate so as to control the opening or closing of the vent groove.

For the thrust vector control, it is preferable that the number of each set of the vent grooves is not less than three.

Preferably, the performance requirements are met by varying the number of sets of aeration slots, the number of slots in each set and the axial position of the slots in each set, depending on the performance requirements and dimensional variations. The respective performance requirements include a height compensation effect and a thrust vector control requirement.

The invention discloses a working method of a controllable slotted spray pipe for a rocket engine, which comprises the following steps: the engine is ignited on the ground and starts to work, at the moment, the spray pipe is in an initial state, all the vent grooves are opened, outside environment air enters the interior of the spray pipe through the vent grooves and disturbs the internal flow, so that the flow separation inside the spray pipe is controlled, the pressure distribution of the inner wall surface of the spray pipe behind the flow separation point is improved, the thrust is larger than that of a conventional spray pipe, and the height compensation effect is achieved.

When the flying height of the rocket is increased and reaches a first preset height, the first group of vent grooves are closed, and gas is prevented from leaking to the environment through the first group of vent grooves; the flying height continues to be increased, and when the flying height reaches a second preset height, the second group of vent grooves are closed; and the rest is repeated until all the vent grooves are closed.

At any flying height, the opening or closing state of one or more groups of vent grooves is asymmetrically controlled to cause the asymmetry of the flow in the spray pipe, thereby achieving the purpose of thrust vector control.

Has the advantages that:

1. the invention discloses a controllable slotted spray pipe for a rocket engine, wherein a plurality of groups of vent grooves are formed in the expansion section of the spray pipe along the axial direction, and a plurality of vent grooves with the same size in the same group are uniformly distributed along the circumferential direction. Outside environment air enters the spray pipe through the vent groove and disturbs the internal flow, so that the flow separation inside the spray pipe is controlled, the pressure distribution of the inner wall surface of the spray pipe after the flow separation point is improved, the thrust is larger than that of a conventional spray pipe, the height compensation effect is achieved, namely the flow separation inside the spray pipe is controlled, the spray pipe efficiency of the rocket engine is obviously improved, and the performance of the spray pipe under the low-altitude working condition is effectively improved.

2. The invention discloses a controllable slotted spray pipe for a rocket engine, which causes asymmetry of flow in the spray pipe by asymmetrically controlling the opening or closing state of one or more groups of vent grooves at any flight height so as to achieve the purpose of thrust vector control.

3. The invention discloses a controllable slotted spray pipe for a rocket engine, wherein a plurality of groups of vent grooves are formed in the expansion section of the spray pipe along the axis direction, and the vent grooves are controlled to be opened or closed by a vent groove control device, so that the expansion ratio of the spray pipe can be ensured, the spray pipe can be prevented from working in an under-expansion state for a long time, and an unsteady and asymmetric complex wave system in the spray pipe caused by high back pressure when the spray pipe is in an over-expansion state can be avoided, and the structural stability of the spray pipe and the orbit entering precision of a rocket can be improved while the efficiency of the spray pipe is remarkably improved.

4. The invention discloses a controllable slotted spray pipe for a rocket engine, which controls the opening or closing of a vent groove through a vent groove control device, wherein the vent groove control device comprises a fixed seat, an actuating cylinder, a connecting piece and a cover plate. The actuating cylinder is used for realizing the feeding and resetting movement along the axial direction. The actuating cylinder is connected with the fixed seat through a rotating shaft, the rotating shaft is driven by the motor to rotate within a certain angle, and the actuating cylinder controls the position of the cover plate so as to control the opening or closing of the vent groove.

Drawings

FIG. 1 is an assembly view of a controllable slotted nozzle for a rocket engine as disclosed herein;

FIG. 2 is a slotted spray tube;

FIG. 3 is a vent slot control device;

FIG. 4 is a schematic view of a first height compensation state;

FIG. 5 is a vent slot closed condition;

FIG. 6 is a schematic view of a second height compensation state;

FIG. 7 is a schematic view of thrust vectoring state 1;

FIG. 8 is a schematic view of thrust vectoring state 2;

the device comprises a slotted spray pipe 1, a slotted spray pipe 11, a first group of vent grooves 12, a second group of vent grooves 2, a vent groove control device 21, a fixed seat 22, a rotating shaft 22, an actuating cylinder 23, a connecting piece 24 and a cover plate 25.

Detailed Description

The conception, the specific structure and the technical effects of the present invention will be further described with reference to the accompanying drawings and embodiments, so as to understand the objects, the features and the effects of the present invention.

As shown in fig. 1 and 2, in the controllable slotted nozzle for a rocket engine disclosed in this embodiment, a plurality of groups of ventilation slots are formed in the nozzle expansion section 1 along the axial direction, and a plurality of ventilation slots with the same size in the same group are uniformly distributed along the circumferential direction.

The outer side of each air channel is provided with an air channel control device 2 matched with the air channel;

the vent groove is controlled to be opened or closed by the vent groove control device 2;

each air channel control device 2 comprises a fixed seat 21, a rotating shaft 22, an actuating cylinder 23, a connecting piece 24 and a cover plate 25; the actuating cylinder 23 is used for realizing the feeding and resetting movement along the axial direction; the actuating cylinder 23 is connected with the fixed seat 21 by a rotating shaft 22, the rotating shaft 22 is driven by a motor to rotate in a certain angle, and the actuating cylinder 23 controls the position of a cover plate 25 so as to control the opening or closing of the vent groove.

According to the performance requirements and the size change of the rocket engine, the corresponding performance requirements are realized by changing the parameters such as the number of the vent grooves, the number of each vent groove group, the positions of each vent groove group and the like. In order to realize thrust vector control, the number of each group of vent grooves is not less than three. For example, as shown in FIG. 1, two sets of 3 aeration grooves may be formed, or as shown in FIG. 2, three sets of four aeration grooves may be formed.

The number n of sets of aeration slots and the position of each set of aeration slots will affect the height compensation effect. In order to maximize the effect of height compensation, the number of sets of aeration grooves and the position of each set of aeration grooves are optimized, the position of the aeration grooves is determined by the expansion ratio e of the cross section at the axial position of the aeration grooves_iAnd (4) showing. The following table lists the corresponding relation between the number of the vent groove groups and the optimal vent groove position, the adopted optimization algorithm is a genetic algorithm, the optimized objective function is the total thrust of the spray pipe in the whole working process, and the calculation parameters adopted in the optimization process refer to a certain type of solid carrier rocket. The maximum expansion ratios for the nozzles listed in the table are all 40, and the total thrust reference is for a conventional nozzle having an expansion ratio of 40. It can be seen that the total gain of the controllable slotted nozzle compared to the conventional nozzle is over 20%, almost comparable to the ideal nozzle.

Table 1 optimized design parameters and performance parameters of controllable slotted spray pipes

The following embodiment is illustrated by way of example of the slotting scheme shown in figure 1.

The working method of the controllable slotted spray pipe for the rocket engine disclosed by the embodiment comprises the following steps:

the engine is ignited at the ground and begins to work, and the spray pipe is in a first height compensation state at the moment. As shown in fig. 4, the two sets of ventilation slots are opened, and the outside air enters the inside of the nozzle through the two sets of ventilation slots, thereby disturbing the internal flow, advancing the position of flow separation in the nozzle, and increasing the pressure of the inner wall surface of the nozzle after the point of flow separation, so that the thrust of the engine can be increased.

When the first predetermined height is reached as the working height is raised, as shown in fig. 5, the vent groove control device 2 controls the first set of vent grooves to close, preventing gas from leaking to the environment. The nozzle operating condition is now the second level compensation condition, as shown in figure 6, with the first set of aeration slots 11 closed and ambient air entering the nozzle interior only through the second set of aeration slots 12.

And the lifting is continued along with the working height, when the second preset height is reached, the vent groove control device 2 controls the second group of vent grooves to be closed, and the spray pipe is in a final height compensation state at the moment, so that the device has no height compensation effect. When the rocket reaches the first preset height and the second preset height, the corresponding vent grooves are closed in time, so that gas leakage under the high-altitude working condition can be prevented. Taking the first set of aeration grooves 11 as an example, the cross-sectional area of the nozzle at the beginning of the aeration groove is A₁When the rocket climbs to a predetermined height H₁At the same time, the first set of ventilation slots is closed, and the ambient atmospheric pressure is p_e1Then A is₁And p_e1Should be in correspondence with

In the above formula A_tIs the area of the throat part of the spray pipe, k is the specific heat ratio of the fuel gas working medium, p_cThe nozzle inlet pressure is a known parameter. And K is a correction coefficient which is related to parameters such as a propellant formula, a spray pipe profile, a working height and the like.

The opening or closing state of any group of three vent grooves is asymmetrically controlled, so that the flow in the spray pipe is asymmetric, and the effect of thrust vector control is achieved. For example, opening two of the second set of louvers 12, one closed as shown in fig. 7, or opening one of the second set of louvers as shown in fig. 8, both closed, may cause an asymmetry in the flow within the nozzle, which has the effect of generating a lateral force F or F' perpendicular to the axial direction, causing the resultant thrust to be offset from the rocket axial direction. The operation shown in fig. 8 can achieve a greater lateral force than the operation shown in fig. 7 at the same operational height, and if the thrust vector angle obtainable by the operation shown in fig. 7 is α, the thrust vector angle obtainable by the operation shown in fig. 8 is 2 α · cos (pi/6).

The direction of the lateral force generated by the above method depends on the direction of the air flow of the associated vent slot. If the airflow direction flows into the spray pipe from the outside after a certain vent groove is opened, the direction of the lateral force generated by opening the vent groove is pointed to the vent groove from the rocket axis, otherwise, the direction of the lateral force is opposite. For example, as shown in fig. 6, if the current operating state is the second altitude compensation state, the external air enters the interior of the nozzle through the opened vent slot, and the direction of the generated lateral force is F; if the current working state is the final height compensation state, the gas in the spray pipe leaks to the environment after the vent groove is opened, and the direction of the generated lateral force is F' shown in the figure.

The above detailed description is intended to illustrate the objects, aspects and advantages of the present invention, and it should be understood that the above detailed description is only exemplary of the present invention and is not intended to limit the scope of the present invention, and any modifications, equivalents, improvements and the like made within the spirit and principle of the present invention should be included in the scope of the present invention.