A device for reducing the servo load torque of a reusable rocket reentry stage engine

Abstract

This application relates to a device for reducing the servo load torque of a reusable rocket's return stage engine, comprising a central engine and multiple skirts. These skirts are foldable and uniformly arranged circumferentially on the outer wall of the central engine's thrust chamber. This application offers the following anticipated technical advantages: the device can significantly reduce the aerodynamic load torque of the central engine's servo system during the return phase, greatly reducing the design complexity of the central engine servo system and lowering the development cost of the reusable rocket; the skirts are folded during the central engine's ascent and return phases, fitting snugly against the outer wall of the central engine's thrust chamber, without affecting the central engine's oscillation operation; the skirts are controlled by linear servos, resulting in a simple structure that can be freely folded and unfolded.

Description

Technical Field

[0001] This invention belongs to the aerospace field and relates to the design of reusable rockets, specifically a device for reducing the servo load torque of a reusable rocket's return stage engine. Background Technology

[0002] With the continuous advancement of global aerospace technology, the space economy is booming. Space "new infrastructure," represented by large-scale low-Earth orbit internet and communication satellite constellations, has become an important national development direction. It is projected that in the next 5 to 10 years, the dense networking and maintenance launches of satellite constellations will create significant market demand for launch vehicles, particularly low-cost launch vehicles. Internationally, SpaceX's Falcon 9 launch vehicle, through reusability, has significantly reduced launch costs, accumulating launch orders exceeding $10 billion and promoting the development of the space economy. Reusability is a crucial way to reduce costs, and developing reusable launch vehicles will greatly enhance my country's ability to access and utilize space.

[0003] The return phase of a recoverable rocket requires multiple activations of the central engine for braking and deceleration. The central engine thrust chamber directly faces the high-speed incoming flow, and the recovered rocket body will experience a high Mach number and high dynamic pressure reentry environment. The central engine servo will bear enormous load torque, placing stringent design requirements on the central engine servo system, resulting in significant design challenges and high costs. Therefore, it is necessary to design a load torque reduction device for the reentry phase engine servo system of a recoverable rocket. Summary of the Invention

[0004] To address the shortcomings or improvement needs of the existing technologies, this invention provides a device for reducing the servo load torque of a reusable rocket's return stage engine. This device can significantly reduce the aerodynamic load torque of the central engine servo system during the return stage, greatly reduce the design difficulty of the central engine servo system, and lower the development cost of reusable rockets.

[0005] To achieve the above objectives, the present invention provides the following technical solution:

[0006] The first aspect proposes a servo load torque reduction device for the reentry stage engine of a reusable rocket, including a central engine and multiple skirts.

[0007] Multiple foldable skirt panels are evenly arranged circumferentially on the outer wall of the thrust chamber of the central engine.

[0008] Preferably, the number of skirts is the same as the number of engines arranged circumferentially around the central engine.

[0009] Preferably, the skirt has three curved edges, the curvature of which matches the curvature of the outer wall of the engine thrust chamber.

[0010] Preferably, the side of the skirt panel closest to the central engine is connected to the outer wall of the thrust chamber of the central engine via a hinge.

[0011] Preferably, it further includes a drive mechanism for controlling the folding and unfolding of the skirt, the drive mechanism comprising a linear servo and a linkage.

[0012] The linear servo is fixedly mounted on the outer wall of the thrust chamber of the central engine. One end of the connecting rod is fixedly connected to the output end of the linear servo, and the other end is hinged to the first surface of the skirt.

[0013] Preferably, the outer edge of the skirt panel is covered with a flexible heat-resistant material.

[0014] Preferably, when the skirt is in a fully extended state, after the circumferentially arranged engines swing 6-8 degrees toward the central engine, the outer wall of the thrust chamber of the circumferentially arranged engines compacts the flexible heat-resistant material on the outer edge of the skirt.

[0015] Preferably, when the skirt is in the folded state, the angle between it and the axis of the central engine is acute, and when the skirt is in the fully unfolded state, it is perpendicular to the axis of the central engine.

[0016] Secondly, this application also proposes a method for using a servo load torque reduction device for a reusable rocket reentry stage engine, comprising the following steps:

[0017] S1. During the rocket's ascent and reentry phases, the skirt is folded during the operation of the central engine. When the skirt is folded, the angle between it and the axis of the central engine is acute, which does not affect the swing operation of the central engine.

[0018] S2. During the aerodynamic deceleration of the rocket's reentry phase, the linear servo motor is activated, and all skirts are fully deployed to be perpendicular to the axis of the central engine;

[0019] S3. The circumferentially arranged engines swing toward the central engine until they reach the maximum swing angle, which is generally 6° to 8°.

[0020] In summary, the above-mentioned one or more technical solutions provided in this application can produce at least the following beneficial effects or advantages:

[0021] 1. This device can greatly reduce the aerodynamic load torque of the central engine servo system during the reentry phase, significantly reduce the design difficulty of the central engine servo system, and reduce the development cost of reusable rockets;

[0022] 2. The skirt is folded during the ascent and return phases of the central engine, fitting against the outer wall of the central engine thrust chamber, without affecting the swing operation of the central engine; 3. The skirt is controlled by a linear servo motor, which has a simple structure and can be freely folded and unfolded. Attached Figure Description

[0023] Figure 1 This is a schematic diagram of the structure of a reusable rocket return stage engine servo load torque reduction device in one embodiment of this application;

[0024] Figure 2 This is a schematic diagram of the skirt panel of the reusable rocket return stage engine servo load torque reduction device in one embodiment of this application, in its folded state.

[0025] Figure 3 This is a partial side view of the skirt of the reusable rocket return stage engine servo load torque reduction device in a folded state according to an embodiment of this application;

[0026] Figure 4 This is a partial side view of the skirt of the reusable rocket return stage engine servo load torque reduction device in the deployed state according to an embodiment of this application;

[0027] Figure 5 This is a schematic diagram of the circumferentially arranged engine swinging towards the central engine in one embodiment of this application, which is a servo load torque reduction device for the return section engine of a reusable rocket.

[0028] In all the accompanying drawings, the same reference numerals are used to denote the same elements or structures, wherein:

[0029] 1-Center engine, 2-Skirt, 201-First surface, 202-Second surface, 3-Linear servo, 4-Linkage, 5-Circumferentially arranged engine. Detailed Implementation

[0030] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention. Furthermore, the technical features involved in the various embodiments of this invention described below can be combined with each other as long as they do not conflict with each other.

[0031] In the description of this invention, it should be understood that the terms "center," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention. In addition, in the description of this invention, unless otherwise stated, "a plurality of" means two or more.

[0032] like Figure 1 As shown, this application provides a servo load torque reduction device for a reusable rocket return stage engine, comprising a central engine and multiple skirts. The skirts are foldable and circumferentially uniformly arranged on the outer wall of the central engine's thrust chamber. The number of skirts corresponds to the number of engines circumferentially arranged on the central engine. In this embodiment, there are six circumferentially arranged engines, and correspondingly, six skirts are provided. Each skirt has three curved edges, a first surface facing the central engine and a second surface facing the circumferential engines when folded. The outer edges of the skirts, i.e., the junctions of the three curved edges and adjacent curved edges, are coated with a flexible heat-resistant material. The curvature of each curved edge is the same as or close to the curvature of the outer wall of the engine's thrust chamber. The curved edge of each skirt closest to the central engine is connected to the outer wall of the central engine's thrust chamber via hinges. The curved edge can be hinged to the outer wall of the thrust chamber at both ends, or at least any two points on the curved edge can be hinged to the outer wall of the thrust chamber.

[0033] like Figures 2 to 4 As shown, each skirt panel is controlled by a drive mechanism consisting of a linear servo and a linkage to fold and unfold. The linear servo is fixedly mounted on the outer wall of the thrust chamber of the central engine. One end of the linkage is fixedly connected to the output end of the linear servo, and the other end is hinged to the first surface of the skirt panel. The extension of the linear servo output end can cause the connected skirt panel to unfold via the linkage, and the retraction of the linear servo output end can cause the connected skirt panel to fold via the linkage. When the skirt panels are fully unfolded, each skirt panel is perpendicular to the axis of the central engine. Figure 5 As shown, when the circumferentially arranged engines swing 6-8 degrees toward the central engine, the flexible heat-resistant material on the outer edge of the skirt panel of the outer wall of the circumferentially arranged engine thrust chamber is compacted. When the skirt panel is in the folded state, the angle between each skirt panel and the axis of the central engine is an acute angle.

[0034] The use of the reusable rocket return stage engine servo load torque reduction device of this application includes the following steps:

[0035] S1. During the rocket's ascent and reentry phases, all skirts are folded during the operation of the central engine. When the skirts are folded, the angle between them and the axis of the central engine is acute, which does not affect the swinging operation of the central engine and can avoid interference between the central engine and the circumferentially arranged engines when the central engine swings.

[0036] S2. During the aerodynamic deceleration of the rocket's reentry phase, the control system, which is electrically connected to the linear servo, controls the linear servo to extend, and all the skirts are fully deployed to be perpendicular to the axis of the central engine.

[0037] S3. The control system controls the circumferentially arranged engines to swing towards the central engine to enter the aerodynamic deceleration stage. When the engines swing to the maximum swing angle, which is generally 6° to 8°, the aerodynamic load torque of the thrust chamber of the circumferentially arranged engines is greatly reduced under the protection of the skirt, which significantly reduces the design requirements for the load torque of the servo system.

[0038] Specifically, during the ignition and liftoff of the reusable rocket, the engine servo load torque reduction device is folded, ensuring it does not interfere with the circumferentially arranged engines when the central engine oscillates. After the recovered rocket separates from the second stage, the engine servo load torque reduction device remains folded. When the recovered rocket re-enters below 50 km altitude, the device unfolds, and the circumferentially arranged engines oscillate radially towards the central engine. All engines at the bottom of the rocket, combined with the servo load torque reduction device, form a blunt-nosed shape. Under the protection of this device, the circumferentially arranged engines experience minimal aerodynamic load torque during the high dynamic pressure re-entry phase. When the recovered rocket re-enters below 5 km altitude, the engine servo load torque reduction device folds again, the central engine restarts, and the recovered rocket completes its landing under the main thrust control of the central engine.

[0039] Using Ansys CFX simulation software, the aerodynamic load data before and after the engine servo load torque reduction device was activated were obtained in Table 1 below. As can be seen from the table, after adding the reusable rocket return stage engine servo load torque reduction device of this application, the maximum servo load torque of the return stage center engine was significantly reduced, and the aerodynamic load torque at different angles of attack decreased by more than 54% compared with the original state.

[0040] Table 1 Comparison of maximum aerodynamic load torque in the central engine's return phase

[0041]

[0042] Those skilled in the art will readily understand that the above description is merely a preferred embodiment of this application and is not intended to limit this application. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this application should be included within the scope of protection of this application.

Claims

1. A recoverable rocket return stage engine servo load torque reduction device comprising a central engine, characterized in that, Also comprising: a plurality of aprons, a plurality of said aprons are circumferentially and uniformly arranged on the outer wall of the thrust chamber of the central engine; the outer edge of each of said plurality of aprons is attached with a flexible heatproof material, when the plurality of said aprons are in a fully unfolded state, the circumferentially arranged engines swing 6-8 degrees towards the central engine, and the outer wall of the thrust chamber of the circumferentially arranged engines compacts the flexible heatproof material of the outer edge of the aprons.

2. The servo load torque reduction device for a recoverable rocket return stage engine according to claim 1, characterized in that: The number of said aprons is consistent with the number of circumferentially arranged engines of the central engine.

3. The servo load torque reduction device for a recoverable rocket return stage engine according to claim 1, characterized in that: Each of said aprons has three curved edges, and the curvature of each curved edge matches the curvature of the outer wall of the thrust chamber of the engine.

4. The servo load torque reduction device for a recoverable rocket return stage engine according to claim 1, characterized in that: One side of said apron close to the central engine is connected to the outer wall of the thrust chamber of the central engine through a hinge.

5. The servo load torque reduction device for a recoverable rocket return stage engine according to claim 1, characterized in that: Also comprising a driving mechanism for folding and unfolding said aprons, said driving mechanism comprising a linear actuator and a connecting rod, said linear actuator is fixedly arranged on the outer wall of the thrust chamber of the central engine, one end of said connecting rod is fixedly connected to the output end of said linear actuator, and the other end is hingedly connected to the first surface of said apron.

6. The servo load torque reduction device for a recoverable rocket return stage engine of claim 1, wherein: When said apron is in a folded state, the included angle between said apron and the axis of the central engine is an acute angle, and when said apron is in a fully unfolded state, said apron is perpendicular to the axis of the central engine.

7. A method of using a servoloading moment reduction device for a recoverable rocket return stage engine, based on the moment reduction device according to any one of claims 1 to 6, characterized in that The method comprises the following steps: S1. During the ascending and returning stages of the rocket, the aprons are in a folded state during the working process of the central engine, and the included angle between the aprons and the axis of the central engine is an acute angle when the aprons are in a folded state, which does not affect the swinging work of the central engine; S2. During the aerodynamic deceleration process of the rocket in the returning stage, the linear actuator is actuated, and all aprons are fully unfolded to be perpendicular to the axis of the central engine; S3. The circumferentially arranged engines swing towards the central engine to the maximum swing angle, and the maximum swing angle is generally 6-8 degrees.

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