Variable geometry turbine split type adjustable blade structure and application thereof

Abstract

The invention discloses a split type adjustable blade structure of a variable geometry turbine and application of the split type adjustable blade structure, and relates to the technical field of variable geometry turbines of aero-engines. An adjustable blade is designed into a fixed petal body and a rotating petal body in a split mode, the fixed petal body is fixed in a turbine blade channel, a blade front edge and a pressure face front blade body are formed, and no radial gap exists between the blade front edge and a casing; the structure stability is ensured; the end region leakage is reduced; the rotating valve body is located on the rear portion of the fixed valve body and connected with an external adjusting mechanism through the rotating boss to achieve angle adjustment, and a blade suction face, a tail edge and a blade body on the rear portion of a pressure face are formed. A molded line transition fit structure is arranged between the fixed petal body and the rotating petal body, and the gap between the fixed petal body and the rotating petal body is kept minimum and mechanical interference does not occur in the initial and adjusting processes. A dynamic and static clearance sealing structure is further designed, and clearance leakage flow is effectively restrained by arranging a sealing groove and sealing teeth. The structure can reduce flow loss and clearance leakage loss and improve turbine efficiency and engine performance.

Description

Technical Field

[0001] The present invention belongs to the technical field of variable geometry turbines for aircraft engines, and relates to turbine blade structure design and adjustment and control technology. Specifically, the present invention provides a variable geometry turbine split-petal adjustable blade structure and its application, which can adjust the throat flow area without destroying the continuity of the suction surface profile, effectively reduce aerodynamic losses and leakage flow, and improve the performance adaptability of the turbine under multiple working conditions. Background Art

[0002] The variable geometry turbine is one of the core technologies for aircraft engines to achieve efficient operation in multiple working conditions. It changes the flow characteristics of the turbine components by adjusting the flow capacity of the blade channel, so that the engine has good performance in various operating conditions (such as takeoff, cruising, and acceleration). It can greatly widen the engine airspace and reduce the engine fuel consumption rate. It is often used in variable cycle engines and adaptive engines and is an important direction for the future development of aircraft engines.

[0003] As a key executive component of a variable geometry turbine, adjustable blades directly affect the efficiency of the variable geometry turbine, the adaptability of the engine airspace, and the efficiency of the thermodynamic cycle. Currently, variable geometry turbine adjustable blade technology mostly adopts two forms: adjustable mounting angle blades and segmented blades. In the adjustable mounting angle blade technology, there is a rotational gap between the blade end and the casing end face, which causes gas leakage and increases aerodynamic losses. In addition, the inlet angle of attack of the blade changes after rotation, which can easily lead to separation of the blade surface under non-design conditions, resulting in large aerodynamic losses. Moreover, the blades will change their position relative to the mainstream direction during rotation, resulting in an increase in the blade drag coefficient and reduced turbine efficiency.

[0004] The segmented blade divides the blade into two sections along the axial direction. The leading edge or trailing edge part of the blade body can rotate, and the other part of the blade is fixed, so as to reduce the radial clearance leakage in the end area of ​​the adjustable installation angle adjustable blade technology and the loss caused by the change of the angle of attack. However, during the adjustment process of this technology, the discontinuous curvature of the blade suction surface profile will lead to significant flow loss, and the circumferential clearance leakage loss from the pressure surface to the suction surface of the blade at the segment is additionally increased, which is difficult to be effectively suppressed by traditional sealing means, especially in high temperature and high pressure environments.

[0005] For example, the axially adjustable variable geometry turbine guide vane disclosed in Chinese invention patent CN116877210A adjusts the throat area through the axial displacement of the secondary blades. However, this technology has a limited adjustment range, has little effect on flow regulation, and does not address the problem of circumferential gap leakage. The linear design of the secondary blade movement trajectory easily leads to airflow disturbances, and the discontinuity of the suction surface profile can lead to severe flow separation. Another example is the flap sliding rotation adjustment method proposed in CN118407809A. Although this method expands the adjustment range through combined actions, the introduction of suction surface boundary layer sweeping significantly increases circumferential leakage losses. Furthermore, the continuity of the suction surface profile is not guaranteed, resulting in sudden changes in local flow velocity and increased aerodynamic losses.

[0006] In summary, the existing variable geometry turbine adjustable blade technology still faces defects such as discontinuous suction surface profile, large leakage losses in the end area and circumferential gap, and flow separation easily induced by angle of attack adjustment during the adjustment process. Therefore, how to reduce flow losses and improve sealing performance while ensuring blade adjustability is a key issue that needs to be urgently addressed in the field of variable geometry turbine technology for aircraft engines. Summary of the Invention

[0007] (1) Purpose of the invention

[0008] In view of the above-mentioned defects and shortcomings of the prior art, the purpose of the present invention is to provide a variable geometry turbine split-petal adjustable blade structure and its application, by dividing the blade into a fixed petal and a rotating petal along the circumferential direction and the axial direction, so that the leading edge of the blade body and part of the pressure surface blade body are fixed, the suction surface, the trailing edge and the rear part of the pressure surface blade body can be rotated, and the suction surface blade body is an integrated profile line, so as to solve the problem of discontinuous curvature of the suction surface profile line during the blade adjustment process, reduce the radial and circumferential gap leakage problems of the variable geometry turbine adjustable blade, and reduce the blade profile loss and gap leakage loss of the variable geometry turbine adjustable blade.

[0009] (2) Technical solution

[0010] In order to achieve the purpose of the invention and solve the technical problems, the present invention adopts the following technical solutions:

[0011] The first object of the present invention is to provide a variable geometry turbine split-petal adjustable blade structure for dynamically adjusting the throat area of ​​the airflow passage in the variable geometry turbine. The adjustable blade includes a fixed petal body and a rotating petal body that cooperate with each other to form the blade body of the adjustable blade, wherein:

[0012] The fixed petal body is fixedly arranged in the turbine blade slot, and its aerodynamic shape forms the leading edge of the adjustable blade body and the blade body in front of the pressure surface. Its upper and lower end surfaces are respectively fixedly connected to the corresponding upper and lower end surfaces of the casing in a manner without radial clearance, so as to ensure the stability of the entire adjustable blade, keep the leading edge position of the adjustable blade unchanged during the rotation adjustment process, and reduce end area leakage;

[0013] The rotating petal body is arranged at the rear position of the fixed petal body, and is arranged as a rotatable structure as a whole. There is a radial gap between the upper and lower end surfaces of the rotating petal body and the corresponding upper and lower side end surfaces of the casing, and they are pivotally connected to each other, so that the rotating petal body can achieve angle adjustment relative to the fixed petal body around its own rotation center; the aerodynamic shape of the rotating petal body starts from the front edge of the suction surface of the adjustable blade and ends at the rear of the pressure surface, forming the entire suction surface, trailing edge and rear blade of the pressure surface of the adjustable blade body, and the rear blade of the pressure surface and the front blade of the pressure surface constitute the entire pressure surface of the adjustable blade body;

[0014] A profile transition matching structure is structurally provided between the fixed petal body and the rotating petal body, so that the gap between the two is kept to a minimum and no mechanical interference occurs during the initial and rotational adjustment process; when the rotating petal body rotates, the suction surface and trailing edge of the adjustable blade are driven to deflect as a whole and change the curvature of the pressure surface, and the flow area of ​​the throat of the turbine blade groove changes accordingly, realizing the flow regulation function of the variable geometry turbine under different working conditions, and reducing the aerodynamic loss and gap leakage loss caused by adjustment through the blade structure partitioning and profile continuity design.

[0015] The second object of the present invention is to provide a variable geometry turbine, including the above-mentioned variable geometry turbine split-petal adjustable blade structure of the present invention.

[0016] The third object of the present invention is to provide a variable cycle engine or adaptive engine, including the above-mentioned variable geometry turbine of the present invention.

[0017] (3) Technical effects

[0018] Compared with the prior art, the adjustable blade structure for a variable geometry turbine and its application of the present invention have the following beneficial and significant technical effects:

[0019] (1) The suction surface profile of the rotating petal is a continuous smooth curve. When adjusting the flow rate, it can rotate around the rotating boss as a whole, avoiding the flow loss caused by the discontinuous curvature of the suction surface profile during the adjustment process.

[0020] (2) The dynamic and static gaps between the rotating petal body and the fixed petal body are located from the front edge of the suction surface to the rear of the pressure surface. By utilizing the flow field characteristics that the pressure on the pressure surface of the blade is greater than the pressure on the suction surface and the pressure on the leading edge is greater than the pressure on the trailing edge, the pressure difference at both ends of the dynamic and static gaps is reduced through the coordination of the circumferential and axial pressure fields, thereby alleviating the leakage flow problem of the circumferential gap of the segmented blade and reducing the leakage flow loss of the circumferential gap.

[0021] (3) There is no radial gap between the fixed flap and the end face of the flow channel, which reduces the radial gap leakage loss of the adjustable installation angle blade. When adjusting the flow rate, the structural angle of the fixed flap leading edge remains unchanged, avoiding the angle of attack loss caused by the rotation of the adjustable installation angle blade. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] The accompanying drawings, which constitute part of the present invention, are provided to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are provided to explain the present invention and do not constitute undue limitations thereon. The embodiments of the present invention will be described in detail below with reference to the accompanying drawings, wherein:

[0023] Figure 1 A schematic plan view of a variable geometry turbine split-petal adjustable blade structure according to the present invention;

[0024] Figure 2 A three-dimensional schematic diagram of the variable geometry turbine split-petal adjustable blade structure of the present invention;

[0025] Figure 3 It is a radial schematic diagram of the split-type adjustable blade structure and the casing end wall;

[0026] Figure 4 Schematic diagram of adjusting the throat area using a split-type adjustable blade structure.

[0027] Description of reference numerals:

[0028] 10-fixed petal body, 11-sealing groove, 20-rotating petal body, 21-sealing tooth, 22-rotating boss, 30-lower receiver end face, 40-upper receiver end face. DETAILED DESCRIPTION

[0029] The present invention aims to provide a variable-geometry turbine split-lobed adjustable blade structure and its application for dynamically adjusting the throat area of ​​the airflow passage in a variable-geometry turbine of an aircraft engine. To make the objectives, technical solutions, and advantages of the present invention more clear, the technical solutions of the present invention are further specifically described below through examples and in conjunction with the accompanying drawings. The following description of the embodiments of the present invention with reference to the accompanying drawings is intended to explain the overall inventive concept of the present invention. The specific data does not represent universal applicability and should not be construed as a limitation of the present invention.

[0030] As a specific example, the variable geometry turbine split-petal adjustable blade structure proposed in the embodiment of the present invention divides the adjustable blade of the traditional integrated structure into two parts along the circumferential direction and the axial direction, such as Figure 1 、 Figure 2 As shown, the adjustable blade includes a separate fixed petal body 10 and a rotating petal body 20, which cooperate to form the blade body of the adjustable blade. Specifically, the fixed petal body 10 is fixedly set in the turbine blade channel, and its aerodynamic shape forms the leading edge of the adjustable blade body and the blade body in front of the pressure surface. Its upper and lower end faces are fixedly connected to the corresponding upper and lower casing end faces 40 and 30 respectively, without radial clearance, to ensure the stability of the entire adjustable blade, maintain the position of the adjustable blade leading edge unchanged during the rotation adjustment process, and reduce end area leakage. Figure 3 This radial clearance-free fixing method not only improves the structural strength of the blade, but also effectively prevents high-temperature and high-pressure combustion gas from leaking from the blade end, thereby improving the efficiency of the turbine.

[0031] In an embodiment of the present invention, the rotating flap body 20 is positioned rearward of the fixed flap body 10. Its upper and lower end faces have radial clearances with the corresponding upper and lower casing end faces 40 and 30, respectively. This radial clearance allows the rotating flap body 20 to rotate freely within a certain range, thereby adjusting the airflow path. A rotating boss 22 is provided on each of its upper and lower end faces. Each rotating boss 22 is a cylindrical structure. One end of the rotating boss 22 is fixed to one of the upper and lower end faces of the rotating flap body 20, and the other end passes through one of the upper and lower casing end faces 40 and 30 to be connected to the turbine's external adjustment mechanism. This is used to locate the rotating flap body's rotation center and transmit rotational torque. The rotating flap body 20 is connected to the external adjustment mechanism through the rotating boss 22, allowing it to rotate around the center of the rotating boss 22. By moving the position of the trailing edge and the suction blade, the throat flow area formed by the trailing edge and the suction blade is changed, ultimately achieving flow regulation. The external adjustment mechanism can adopt various drive modes, such as electric, hydraulic, or pneumatic, and can be selected according to actual needs.

[0032] The aerodynamic shape of the rotating flap body 20 starts from the front edge of the suction surface of the adjustable blade and ends at the rear of the pressure surface, forming the entire suction surface, trailing edge and rear blade body of the adjustable blade body. The rear blade body of the pressure surface and the front blade body of the pressure surface constitute the entire pressure surface of the adjustable blade body. In addition, a profile transition matching structure is provided between the fixed flap body 10 and the rotating flap body 20 in the structure, so that the gap between the two is kept to a minimum and no mechanical interference occurs during the initial and rotational adjustment process. When the rotating flap body 20 rotates, the suction surface and trailing edge of the adjustable blade are driven to deflect as a whole and change the curvature of the pressure surface. The flow area of ​​the throat of the turbine blade slot changes accordingly, realizing the flow regulation function of the variable geometry turbine under different working conditions, and reducing the aerodynamic loss and gap leakage loss caused by adjustment through blade structure partitioning and profile continuity design.

[0033] Preferably, the axis of the rotating boss 22 coincides with the center of rotation, and its axial position is determined through computational optimization to minimize the sum of the circumferential gap leakage loss between the fixed flap body 10 and the rotating flap body 20 and the radial gap leakage loss at the end of the rotating flap body 20. It should be noted that the closer the rotating boss 22 is to the rear of the blade, the smaller the proportion of the pressure surface of the rotating flap body 20 in the axial direction, that is, the smaller the area of ​​the radial gap, and the reduced radial leakage loss. However, the closer the rotating boss 22 is to the rear of the blade, the closer the circumferential gap between the fixed flap body 10 and the rotating flap body 20 is to the rear, where the pressure is lower, and the pressure difference with the other end of the gap increases, increasing the circumferential gap leakage loss. Therefore, there is an optimal axial position for the rotating boss 22, which needs to be determined through specific calculations based on the blade operating conditions to minimize the sum of the radial and circumferential leakage losses. The larger the boss radius, the more significant the blocking effect on the radial gap leakage flow at the end of the rotating flap body 10, which can reduce the radial gap leakage loss.

[0034] In a preferred embodiment, the rotation range of the rotating flap body 20 is designed to be +4° to -16.5°. When the rotating flap body 20 and the fixed flap body 10 are at the +4° position, the throat passage flow area is the largest, corresponding to the maximum flow state. When the rotating flap body is rotated to -16.5°, the trailing edge of the rotating flap body contacts the suction surface, the throat width is zero, corresponding to the minimum flow state. Figure 4As shown, when the rotating flap body 20 rotates to +4°, the corresponding adjustable blade throat width is Xmax. At this time, the rotating flap body 20 contacts the fixed flap body 10, and the flow area reaches the maximum value. When the rotating flap body 20 rotates to -16.5°, the trailing edge of the rotating flap body 20 touches the suction surface blade, and the throat width is 0. At this time, the adjustable blade flow reaches the minimum value. If the radial clearance between the rotating flap and the end wall of the casing is small, it will mechanically interfere with the casing and cannot continue to rotate before rotating to a throat width of 0, and the minimum flow value has been reached. The design of this rotation range fully considers the flow requirements of the engine under different operating conditions and ensures the strength and reliability of the blade structure.

[0035] The present invention proposes an adjustable blade dynamic and static clearance sealing structure, such as Figure 1 、 Figure 2 As shown, 11 is a sealing groove and 21 is a sealing tooth. Specifically, a sealing groove 11 is provided on one side of the leading edge suction surface of the fixed flap body 10, located at the junction of the leading edge of the fixed flap body 10 and the rotating flap body 20. A sealing tooth 21 is provided on the leading edge of the rotating flap body 20, located at the junction of the suction surface of the rotating flap body 20 and the leading edge of the fixed flap body 10. When the rotating flap body 20 rotates within a preset angle range, the sealing tooth 21 remains inserted into the sealing groove 11, and the combination of the two is used to seal the leakage flow in the gap between the fixed flap body 10 and the rotating flap body 20. For example, when the rotating flap body rotates within the range of +4° to -7°, the sealing tooth 21 remains inserted into the sealing groove 11, forming a sealing effect on the gap flow between the fixed flap body 10 and the rotating flap body 20. When the rotating petal body rotates to -7°, the corresponding adjustable blade throat width is X_1. After the rotating petal body rotates beyond -7°, the sealing effect of the sealing groove 11 and the sealing tooth 21 disappears, but the flow rate can still be adjusted until the minimum flow rate adjustment capacity.

[0036] In a preferred embodiment, Figure 1 、 Figure 2 As shown, the tail of the fixed flap body 10 is designed as a concave arc surface, the center of which is located at the center of the rotating boss 22. Constrained by the thickness of the blades in this embodiment, the radius of the concave arc surface is selected to be 3mm. The junction of the trailing edges of the rotating flap body 10 and the fixed flap body 22 is designed as a convex arc surface, the center of which is located at the center of the rotating boss, with a radius of 2.75mm. The gap between the rotating flap body and the fixed flap body is maintained at 0.25mm to ensure that there is no mechanical interference during the flow regulation process, and the gap size is not affected by the blade rotation angle. The boss radius needs to be smaller than the radius of the convex arc surface of the rotating flap body. Constrained by the size of the turbine external adjustment mechanism in this embodiment, the boss radius is selected to be 1.5mm.

[0037] In a preferred embodiment, Figure 1 、 Figure 2As shown, the front side profile of the sealing groove 11 is a concave arc profile, the center of the concave arc profile is concentric with the rotating boss 22, and the radius is 18.35mm; the front side profile of the sealing tooth 21 is a convex arc profile, the center of the convex arc profile is concentric with the rotating boss, and the radius is 18.1mm; the gap distance between the sealing groove 11 and the sealing tooth 21 is maintained at 0.25mm, ensuring that there is no mechanical interference during the flow regulation process, and the gap size is not affected by the blade rotation angle.

[0038] In the variable geometry turbine split-petal adjustable blade structure of the present invention, the rotating petal body includes a complete suction surface profile. When rotating, the blade suction surface profile is complete and continuous, avoiding the suction surface protrusion that occurs during the rotation of the segmented blade, and preventing the flow separation loss of the air induced thereby. The dynamic and static gaps between the fixed petal body and the rotating petal body appear at the leading edge close to the suction surface position and the pressure surface close to the trailing edge position. By adjusting the circumferential and axial positions, the pressure difference at both ends of the gap is reduced, thereby alleviating the circumferential gap leakage flow and slowing down the circumferential gap leakage loss at the segmented blade. The leading edge of the fixed petal body is fixed, which can solve the problem of increased angle of attack loss under variable working conditions faced by adjustable installation angle blades. In addition, there is no radial gap between the upper and lower ends of the fixed petal and the end face of the flow channel, which can reduce the leakage flow area of ​​the end area, thereby slowing down the end area leakage loss problem of the adjustable installation angle blade.

[0039] Furthermore, to achieve precise control of the variable-geometry turbine, an advanced control system can be employed. This control system comprises sensors, actuators, and a controller. Sensors monitor engine operating parameters such as speed, temperature, and pressure in real time. Based on pre-set control strategies and sensor data, the controller controls the actuators to adjust the angle of the rotating lobes, achieving precise control of the airflow channel area to meet performance requirements under varying operating conditions. The control system can also automatically adjust control parameters based on the actual engine operating status, achieving adaptive control of the variable-geometry turbine.

[0040] Furthermore, it should be noted that the specific embodiments described in this specification may vary in shape, designation, dimensions, and other aspects of their components. Any equivalent or simple variation based on the structure, features, and principles described in this patented concept is included within the scope of protection of this patent. Persons skilled in the art may make various modifications, additions, or substitutions to the described specific embodiments, and these modifications, as long as they do not deviate from the structure of the present invention or exceed the scope defined by these claims, shall fall within the scope of protection of this invention.

Claims

1. A variable geometry turbine split-petal adjustable blade structure for dynamic adjustment of the throat area of ​​the variable geometry turbine airflow channel, characterized in that: The adjustable blade includes a fixed petal body and a rotating petal body which are separately arranged, and the two cooperate with each other to form the blade body of the adjustable blade, wherein: The fixed petal body is fixedly arranged in the turbine blade slot, and its aerodynamic shape forms the leading edge of the adjustable blade body and the front blade body of the pressure surface, and its upper and lower end surfaces are respectively fixedly connected to the corresponding upper and lower end surfaces of the casing in a manner without radial clearance; The rotating petal body is arranged at the rear position of the fixed petal body, and is arranged as a rotatable structure as a whole. There is a radial gap between the upper and lower end surfaces of the rotating petal body and the corresponding upper and lower side end surfaces of the casing, and they are pivotally connected to each other, so that the rotating petal body can achieve angle adjustment relative to the fixed petal body around its own rotation center; the aerodynamic shape of the rotating petal body starts from the front edge of the suction surface of the adjustable blade and ends at the rear of the pressure surface, forming the entire suction surface, trailing edge and rear blade of the pressure surface of the adjustable blade body, and the rear blade of the pressure surface and the front blade of the pressure surface constitute the entire pressure surface of the adjustable blade body; A profile transition matching structure is provided between the fixed petal body and the rotating petal body, so that the gap between the two is kept to a minimum and no mechanical interference occurs during the initial and adjustment process; when the rotating petal body rotates, the suction surface and trailing edge of the adjustable blade are driven to deflect as a whole and change the curvature of the pressure surface, and the flow area of ​​the throat of the turbine blade groove changes accordingly.

2. The variable geometry turbine split-petal adjustable blade structure according to claim 1, characterized in that: The rotating petal body is connected to the external adjustment mechanism through rotating bosses arranged on its upper and lower end surfaces. Each rotating boss is a cylindrical structure, one end of which is fixed to one of the upper and lower end surfaces of the rotating petal body, and the other end passes through one of the upper and lower side end surfaces of the casing and is transmission-connected to the turbine external adjustment mechanism, which is used to locate the rotation center of the rotating petal body and transmit the rotational torque, driving the rotating petal body to rotate around its own rotation center.

3. The variable geometry turbine split-petal adjustable blade structure according to claim 2, characterized in that: The axis of the rotating boss coincides with the center of rotation, and its axial position selection needs to be determined through calculation optimization so that the sum of the circumferential gap leakage loss between the fixed petal body and the rotating petal body and the radial gap leakage loss at the end of the rotating petal body is minimized.

4. The variable geometry turbine split-petal adjustable blade structure according to claim 2 or 3, characterized in that: A dynamic and static sealing structure is provided at the junction of the leading edge of the fixed flap body and the suction surface of the rotating flap body, including a sealing groove structure formed on one side of the suction surface of the leading edge of the fixed flap body and a sealing tooth structure formed on the leading edge of the rotating flap body. When the rotating flap body rotates within a preset angle range, the sealing teeth remain inserted in the sealing groove to form a dynamic and static sealing fit, thereby sealing the leakage flow in the gap between the fixed flap body and the rotating flap body.

5. The variable geometry turbine split-petal adjustable blade structure according to claim 4, characterized in that: The front side profile of the sealing groove is an inward-concave arc profile, the center of which is concentric with the rotating boss; the front side profile of the sealing tooth is an outward-convex arc profile, the center of which is concentric with the rotating boss, and its radius is smaller than the inward-concave arc profile of the front side of the sealing groove. The two cooperate to ensure that the flow area of ​​the sealing gap between the rotating petal body and the fixed petal body is minimized, and there is no mechanical interference during the rotation process.

6. The variable geometry turbine split-petal adjustable blade structure according to claim 2 or 3, characterized in that: The tail of the fixed flap body is designed as a concave arc surface, the center of the concave arc surface is concentric with the rotating boss, and the radius of the concave arc surface is larger than the radius of the rotating boss; the junction of the rotating flap body and the tail of the fixed flap body is designed as a convex arc surface, the convex arc surface is adapted to the concave arc surface, and the center of the convex arc surface is concentric with the rotating boss, the radius of the convex arc surface is larger than the radius of the rotating boss and smaller than the radius of the concave arc surface at the tail of the fixed flap body, the two cooperate to ensure that the gap flow area between the rotating flap body and the fixed flap body on the pressure surface is minimized, and there is no mechanical interference during rotation.

7. The variable geometry turbine split-petal adjustable blade structure according to claim 2, characterized in that: The turbine external adjustment mechanism drives the rotating petal body to move through electric, hydraulic or pneumatic drive; the rotation range of the rotating petal body is designed as follows: when the rotating petal body contacts the fixed petal body, the throat channel flow area formed is the largest, corresponding to the maximum flow state, and it rotates until the trailing edge of the rotating petal body contacts the suction surface, the throat width is zero, or it rotates until it cannot continue to rotate due to mechanical interference from the casing, corresponding to the minimum flow state.

8. The variable geometry turbine split-petal adjustable blade structure according to claim 7, characterized in that: When the rotating petal body rotates within the effective sealing angle range, the sealing teeth and the sealing grooves maintain an effective engagement state, and the dynamic and static gap sealing structure maintains the sealing function; when the rotation angle exceeds the effective sealing angle, the engagement state of the sealing structure is released, and the blade adjustment can still be achieved until the minimum flow area state is reached.

9. A variable geometry turbine, characterized in that: It comprises the variable geometry turbine split-petal adjustable blade structure according to any one of claims 1 to 8.

10. A variable cycle engine or adaptive engine, characterized in that: Including the variable geometry turbine as described in claim 9.

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