Tail nozzle adjustment mechanism and design method

Abstract

This application proposes a tail nozzle adjustment mechanism and design method, the steps include: S1: designing a fan-shaped transition area between the tail nozzle circular convergence section and the tail nozzle square expansion section; S2: adopting a rotation and translation composite double-plate structure, hinged connecting rods on the outer surface of the translation plate, and rotatably connected at one end of the translation plate to one end of the rotation plate; the other end of the rotation plate is rotatably fixed to the tail nozzle circular convergence section, and the front end of the rotation is connected to the translation plate, the translation plate is tightly fitted with the tail nozzle square expansion section, and the outer surface of the rotation plate is also connected to the translation plate by a hydraulic push rod, so that the translation plate and the rotation plate can move in coordination. Through this design method, in the process of opening and closing, it meets the change of the tail nozzle throat area, can be started and stopped at any time, and continuously adjusted to meet the thrust requirements, and meet the airtightness conditions when fully closed.

Description

Technical Field

[0001] The present application relates to the technical field of tail nozzles, and in particular to a tail nozzle adjustment mechanism and a design method. Background Art

[0002] Achieving hypersonic flight is an important scientific and technological means to enhance my country's comprehensive national strength, but it is difficult to achieve hypersonic flight with just a single air-breathing engine. Therefore, to meet the needs of hypersonic flight, a combined engine came into being.

[0003] Combined engines fall into two categories: rocket-based combined cycle (RBCC) and turbine-based combined cycle (TBCC). These engines combine the technologies of turbine engines (including turbojets and turbofans) and ramjets (including scramjets, scramjets, and dual-mode combustion ramjets). These engines leverage the strengths of turbine engines and ramjets within their respective flight ranges, offering advantages such as conventional takeoff and landing, reusability, high reliability, excellent low-speed performance, and low technical risk, demonstrating promising engineering applications.

[0004] The tail nozzle is a crucial component of the engine and a crucial source of power. As the Mach number of a hypersonic vehicle changes, the tail nozzle must adjust its throat area and exit cross-sectional area to fully expand the air at the exit, achieving the most effective thrust and unleashing the engine's optimal performance. Furthermore, the tail nozzle's opening and closing must be coordinated with the inlet switch, closing the corresponding engine channel under various operating conditions to achieve the desired flight state.

[0005] One of the problems brought about by the invention of the combined engine is how to match the operating mode of each engine, realize the opening and closing of the engine under various working conditions, and realize the mode conversion of each engine. Taking the engine as an example, in order to realize the mode conversion of the tail nozzle, and to achieve the best regulation performance of the tail nozzle on the airflow under the system requirement of saving thrust, it is necessary to design a corresponding tail nozzle adjustment mechanism to realize the opening and closing of the turbine channel. Relying solely on the rotation of a single partition to achieve the mode conversion of the tail nozzle will cause leakage problems, and there will be separation of the airflow boundary layer, which aggravates flow loss. During the conversion process, the diverter plate will be subjected to high temperature and excessive air load problems. Therefore, it is necessary to propose a new design method for the tail nozzle adjustment mechanism to change the airflow performance and improve flight efficiency. Summary of the Invention

[0006] In order to solve the above technical problems, the present application provides a tail nozzle adjustment mechanism and a design method.

[0007] In one aspect of the present application, a method for designing a tail nozzle adjustment mechanism is proposed, comprising the following steps:

[0008] S1: Design a fan-shaped transition area between the circular convergent section and the square divergent section of the tail nozzle;

[0009] S2: A composite double-plate structure of rotation and translation is adopted, with a connecting rod hinged on the outer surface of the translation plate and one end of the translation plate rotatably connected to one end of the rotation plate; the other end of the rotation plate is rotatably fixed to the circular convergence section of the tail nozzle, and the front end of the rotation is connected to the translation plate. The translation plate fits tightly with the square expansion section of the tail nozzle, and the outer surface of the rotation plate is also connected to the translation plate through a hydraulic push rod, so that the translation plate and the rotation plate can move in coordination.

[0010] Through the above technical solution, the translation plate drives the rotating plate to move under the action of the driving force until the translation plate is completely in contact with the lower wall of the tail nozzle, thereby realizing the characteristic of complete closure of the nozzle pipe, and the driving force driving the translation plate to move drives the rotating plate to rotate through the hydraulic push rod link, thereby realizing the purpose of continuous adjustment of the nozzle area and starting and stopping at any time.

[0011] Preferably, the circular tail nozzle is extended inwardly to transform into a square structure so that the tail nozzle has the same throat area in each part, ensuring that the performance of the tail nozzle is not much different before and after, and the fan-shaped transition area is set between the circular convergent section and the square expansion section of the tail nozzle.

[0012] Through the above technical solution, the tail nozzle has the same throat area in each part, the performance of the tail nozzle is not much different before and after, and the throat area of ​​the tail nozzle is adjustable.

[0013] In a specific embodiment, the tail nozzle includes a circular convergent section, a square expansion section, and a fan-shaped transition area.

[0014] Preferably, a fixed base is provided above the circular convergent section of the tail nozzle, and the fixed base is connected to the translation plate through an active push rod and a driven rotating rod, and can drive the translation plate to move.

[0015] Preferably, the translation plate is an arc-shaped structure, and the inner surface contour of the translation plate is the same as the lower wall contour of the square expansion section of the tail nozzle.

[0016] Preferably, the rotating plate is arranged in the fan-shaped transition area of ​​the tail nozzle.

[0017] Through the above technical solutions, the diverter plate adopts a rotational method to improve the expansion ratio and enhance the airflow performance; the translational method can expand the throat area, taking into account the thrust performance and flow requirements of each nozzle, and making it easy to maintain air tightness; the rotation plus translational adjustment method is adopted, and an external hydraulic push rod is used to connect the rotating plate and the translational plate, thereby improving the reliability of the adjustment mechanism; moreover, the translational plate is designed to be a curved shape with a certain curvature to avoid boundary layer separation. The curved surface structure is conducive to the smooth flow of air, reduces gas flow loss, and avoids high temperature and excessive air load.

[0018] In another aspect of the present application, a tail nozzle adjustment mechanism is proposed, including: a tail nozzle, a translation plate, and a rotating plate, one end of the rotating plate is rotatably fixedly connected to the tail nozzle, and the other end of the rotating plate is rotatably fixedly connected to the translation plate; the translation plate has a certain curvature, and the translation plate can drive the rotating plate to rotate when it moves.

[0019] The tail nozzle includes a circular convergent section, a square expansion section, and a fan-shaped transition area.

[0020] The inner surface profile of the translation plate is the same as the lower wall profile of the square expansion section of the tail nozzle, so that the inner surface of the translation plate can fit closely with the lower wall of the square expansion section of the tail nozzle.

[0021] The rotating plate is arranged in the fan-shaped transition area of ​​the tail nozzle.

[0022] A fixed base is provided above the circular convergent section of the tail nozzle, and the fixed base is connected to the translation plate through an active push rod and a driven rotating rod, and can drive the translation plate to move.

[0023] The translation plate and the rotating plate are connected via a hydraulic push rod, so that when the translation plate moves, the rotating plate can be driven to rotate around the convergent section of the tail nozzle.

[0024] Compared with the prior art, the beneficial results of this application are:

[0025] The modal conversion adjustment process is controllable, meeting the internal requirements of size and space constraints. The translating plate fits tightly with the upper and lower walls of the tail nozzle, matching the tail nozzle configuration. The translating thin plate can not only fully close the square channel, but also avoid excessive burden on the overall weight of the fuselage. It can meet the complex environment of high-altitude and high-speed flight of aircraft.

[0026] The translational plate's external hinged connecting rod shaft structure meets the system's thrust-saving requirements. The adjustment mechanism is placed outside the fuselage, eliminating the need to occupy the internal tail nozzle space.

[0027] The design concept and functional principle of the present invention are applicable to square pipes and square-like pipes, and the solution of pushing the translation plate to drive the rotation plate to rotate to adjust the area of ​​the pipe ventilation opening is adopted. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] The accompanying drawings are included to provide a further understanding of the embodiments and are incorporated into and constitute a part of this specification. The accompanying drawings illustrate the embodiments and, together with the description, serve to explain the principles of the present application. Other embodiments and many of the expected advantages of the embodiments will be readily apparent as they become better understood by reference to the following detailed description. The elements of the drawings are not necessarily to scale with respect to each other. Like reference numerals designate corresponding similar parts.

[0029] Figure 1 1 is a schematic structural diagram of a tail nozzle adjustment mechanism when it is opened according to an embodiment of the present application;

[0030] Figure 2 1 is a schematic structural diagram of a tail nozzle adjustment mechanism when closed according to an embodiment of the present application;

[0031] Figure 3 is an exploded view of a tail nozzle adjustment mechanism according to an embodiment of the present application;

[0032] Figure 4 This is a schematic diagram of a round-to-square nozzle structure after adding a fan-shaped transition area to a tail nozzle adjustment mechanism according to an embodiment of the present application.

[0033] The meaning of each number in the figure is: 1. Fixed base; 2. Active push rod; 3. Hydraulic push rod housing; 4. Driven rotating rod; 5. Translation plate; 6. Tail nozzle; 7. Hydraulic push rod; 8. Rotating plate; 9. Tail nozzle circular convergence section; 10. Fan-shaped transition area; 11. Tail nozzle square expansion section. DETAILED DESCRIPTION

[0034] In the following detailed description, reference is made to the accompanying drawings, which form a part of the detailed description and are shown by illustrative specific embodiments in which the present application can be practiced. In this regard, directional terms, such as "top", "bottom", "left", "right", "up", "down", etc., are used with reference to the orientation of the figures being described. Because the components of the embodiments can be positioned in several different orientations, directional terms are used for illustrative purposes and are in no way limiting. It should be understood that other embodiments can be utilized or logical changes can be made without departing from the scope of the present application. Therefore, the following detailed description should not be taken in a limiting sense, and the scope of the present application is defined by the appended claims.

[0035] This application proposes a tail nozzle adjustment mechanism and design method. Figure 1 1 is a schematic structural diagram of a tail nozzle adjustment mechanism when it is opened according to an embodiment of the present application. Figure 2 This is a structural diagram of a tail nozzle adjustment mechanism when it is closed according to an embodiment of the present application, combined with Figure 1 、 Figure 2As shown, the fixed base 1 is arranged above the circular convergent section 9 of the tail nozzle, one end of the active push rod 2 is connected to the fixed base 1, and the other end of the active push rod 2 is hinged to the driven rotating rod 4; the driven rotating rod 4 is hinged to the translation plate 5, and under the action of the driving force, the active push rod 2 drives the driven rotating rod 4 to move, thereby causing the translation plate 5 to move. Furthermore, a hydraulic push rod 7 is hinged to the outer surface of the rotating plate 8 and is connected to the translation plate 5 through the hydraulic push rod 7; when the translation plate 5 moves, the translation plate 5 can drive the rotating plate 8 to rotate through the hydraulic push rod 7, so that the closing process of the rotating plate 8 and the translation plate 5 is continuously adjustable and controllable until the translation plate 5 is completely in contact with the lower wall of the tail nozzle 6 and is in a completely closed state.

[0036] Figure 3 : is an exploded view of a tail nozzle adjustment mechanism according to an embodiment of the present application. Figure 4 : is a schematic diagram of a round-to-square nozzle structure of a tail nozzle adjustment mechanism after adding a fan-shaped transition area according to an embodiment of the present application, such as Figure 3 、 4 As shown, the tail nozzle 6 includes a circular convergent section 9, a fan-shaped transition area 10, and a square expansion section 11 of the tail nozzle. One end of the rotating plate 8 is rotatably connected to the circular expansion section 9 of the tail nozzle, and the other end is rotatably connected to the translation plate 5. The rotating plate 8 is arranged above the fan-shaped transition area 10, and its outer surface is also connected to the translation plate 5 through a hydraulic push rod 7. A driven rotating rod 4 is also hinged on the outer surface of the translation plate 5. The driven rotating rod 4 is connected to the active push rod 2, and the active push rod 2 is connected to the fixed base 1. Through this connection method, the driving force is provided to the translation plate 5.

[0037] In addition, the translating plate 5 has a certain curvature, so that when it moves to the closed state, it can fit with the inner wall of the square expansion section 11 of the tail nozzle. The shape design of the left and right edges of the translating plate 5 is closely fitted with the contours of the walls on both sides of the square expansion section 11 of the tail nozzle, ensuring the sealing characteristics when fully closed.

[0038] The present invention is applicable to square pipes and similar square pipes, and is a solution for adjusting the ventilation opening area of ​​the pipe by pushing the translation plate to drive the rotation plate to rotate.

[0039] Obviously, those skilled in the art can make various modifications and changes to the embodiments of the present application without departing from the spirit and scope of the present application. In this way, if these modifications and changes are within the scope of the claims of the present application and their equivalents, the present application is also intended to cover these modifications and changes. The word "comprising" does not exclude the presence of other elements or steps not listed in the claims. The simple fact that certain measures are recited in mutually different dependent claims does not indicate that the combination of these measures cannot be used to advantage. Any reference signs in the claims should not be considered as limiting the scope.

Claims

1. A design method for a tail nozzle adjustment mechanism, characterized in that: The following steps are involved: S1: A fan-shaped transition region is designed between the circular convergent section and the square divergent section of the tail nozzle; a fixed base is provided above the circular convergent section of the tail nozzle, and the fixed base is connected to the translation plate via an active push rod and a driven rotating rod, and can drive the translation plate to move; S2: A composite double-plate structure of rotation and translation is adopted, with a connecting rod hinged on the outer surface of the translation plate and one end of the translation plate rotatably connected to one end of the rotation plate; the other end of the rotation plate is rotatably connected to the circular convergent section of the tail nozzle, and the front end of the rotation plate is connected to the translation plate, the translation plate is an arc-shaped structure, and the inner surface contour of the translation plate is the same as the lower wall contour of the square expansion section of the tail nozzle, the translation plate fits tightly with the square expansion section of the tail nozzle, and the outer surface of the rotation plate is also connected to the translation plate through a hydraulic push rod, so that the translation plate and the rotation plate can move in coordination.

2. The design method of a tail nozzle adjustment mechanism according to claim 1, characterized in that: In S1, an equal cross-sectional area axisymmetric design method is adopted to extend the circular tail nozzle inwardly into a square structure, and the fan-shaped transition area is set between the circular convergent section of the tail nozzle and the square expansion section of the tail nozzle.

3. The design method of a tail nozzle adjustment mechanism according to claim 2, characterized in that: The rotating plate is arranged in the fan-shaped transition area of ​​the tail nozzle.

4. The design method of a tail nozzle adjustment mechanism according to claim 2, characterized in that: The translation plate and the rotation plate are connected via a hydraulic push rod.

5. The method for designing a tail nozzle adjustment mechanism according to claim 2, characterized in that: The rotating plate is in a closed state and fits with the rear end of the circular convergent section of the tail nozzle.

6. A tail nozzle adjustment mechanism, characterized in that: The tail nozzle adjustment mechanism is manufactured by the design method according to any one of claims 1-5.

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