A flow area adjustable blade profile pre-swirl nozzle structure

Abstract

This invention relates to a pre-swirl nozzle structure with adjustable flow area, belonging to the technical field of pre-swirl cooling systems in gas turbine engines. This invention utilizes a micro-servo mechanism and a linkage mechanism to adjust the relative position of the solid thin shell on the blade back and the blade body, thereby changing the airflow channel area of ​​the pre-swirl nozzle. This allows for effective regulation of the cooling air volume. During adjustment, the aerodynamic airfoil design of the blade head and blade back is maintained on both sides of the airflow channel, avoiding additional aerodynamic losses. This enables the provision of different cooling air volumes to the pre-swirl cooling system under different operating conditions, reducing the overall fuel consumption rate of the gas turbine engine across all operating conditions. When the variable cycle engine undergoes component adjustments and mode switching in the main flow path, the pre-swirl nozzle structure can also adjust accordingly, improving thrust and safety across the entire flight envelope. Furthermore, the adjustment process maintains the aerodynamic profile design, avoiding additional aerodynamic losses.

Description

Technical Field

[0001] This invention relates to the field of pre-swirl cooling systems in gas turbine engines, and specifically to a blade-shaped pre-swirl nozzle structure with adjustable flow area. Background Technology

[0002] The pre-swirl cooling system of modern gas turbine engines provides turbine blades with cooling gas at suitable pressure and temperature, ensuring reliable blade operation in high-temperature combustion environments and extending blade life. A typical pre-swirl cooling system draws cooling air from the combustion chamber annulus, passes it through pre-swirl nozzles into the turbine disk inlet chamber, and primarily merges into the mains flow through the turbine blade film gas holes. This portion of cooling air does not participate in the thermodynamic cycle of the mains flow, therefore it does not contribute to the output power of the gas turbine engine. Excessive cooling air intake will increase engine fuel consumption, adversely affecting overall performance. Fuel consumption is a crucial indicator for the competitiveness of modern gas turbine engines in the international market; therefore, the negative impact of excessive fuel consumption due to redundant cooling air intake should be avoided as much as possible.

[0003] Currently, the design of gas turbine engines typically selects the maximum thermal condition at full power output with the highest temperature level to assess and design the cooling gas volume requirement. Under this condition, the geometric parameters of the pre-swirl cooling system components that meet the turbine blade cooling requirements are determined. When the engine operates at partial power output, the gas temperature level decreases, and the blade cooling gas volume requirement drops, no longer needing to provide the same cooling gas volume as under the maximum thermal condition. However, because the geometry of the pre-swirl cooling system components is fixed, the proportion of induced draft cooling gas remains essentially unchanged. In this case, the cooling gas volume becomes relatively redundant, which is not conducive to reducing engine fuel consumption.

[0004] Furthermore, existing variable cycle engines, in order to meet the flight requirements across a wide airspace and speed range, achieve different operating modes by adjusting the main runner components under different operating conditions. For example, a turbofan mode is used at low altitudes and low speeds, while a turbojet mode is used at high altitudes and high speeds. This involves the issue of engine state matching during mode switching. During the mode switching process of a variable cycle engine, the engine's pre-swirl cooling system generally uses a fixed bleed area method to design the geometric parameters of the blade tip and the back surface of the blade. By optimizing the geometric parameters of the blade tip and the back surface of the blade, its performance is improved.

[0005] However, with a fixed air intake area, the pre-swirling air cooling system cannot respond to drastic changes in the aerodynamic parameters of the main flow components. This results in the blade head and blade back not being able to adjust accordingly to changes in the state of the main flow components, which cannot guarantee the safety performance of key functional indicators of the pre-swirling air cooling system (such as blade disk cooling, rim sealing, axial force control, etc.) and increases the risk of air system instability. Summary of the Invention

[0006] In view of the above problems, the present invention provides a blade-shaped pre-swirl nozzle structure with adjustable flow area, which can provide different cooling air volumes to the pre-swirl cooling air system under different operating conditions, thereby reducing the overall fuel consumption rate of the gas turbine engine under all operating conditions. At the same time, without changing the optimized aerodynamic design of the blade-shaped pre-swirl nozzle, the flow area of ​​the nozzle can be adjusted. The adjustment process maintains the aerodynamic design and avoids additional losses. The pre-swirl system can also be adjusted according to the state changes of the main flow path of the variable cycle engine, thereby improving the performance and safety of the entire flight envelope.

[0007] The present invention provides a blade-shaped pre-swirl nozzle structure with adjustable flow area. The blade-shaped pre-swirl nozzle structure includes: nozzle blades, bottom support plate (3) and top support plate (4); the nozzle blades include blade body (1) and blade back solid thin shell (2);

[0008] The blade body is fixedly mounted on the bottom support plate; the blade back solid shell (2) is movably mounted between the bottom support plate and the top support plate.

[0009] Preferably, both the bottom support plate 3 and the top L-shaped support plate 4 are annular support plates, and multiple sets of nozzle blades are arranged circumferentially along the inner plate surface of the bottom support plate (3) and the top support plate (4).

[0010] The outer peripheral wall of the solid thin shell on the back of each set of nozzle blades forms an airflow channel between it and the inner peripheral wall of the blade body of the adjacent set of nozzle blades; such as Figure 1 As shown; the blade body 1 and the solid thin shell 2 on the back of the blade are horizontally placed between the bottom support plate 3 and the top L-shaped support plate, and the blade body 1 is fixedly connected to the bottom support plate 3 and the top L-shaped support plate respectively.

[0011] Preferably, the bottom support plate and the top L-shaped support plate are stator support plates; the blade body 1 is fixedly installed on the stator support plate, and the blade back solid shell 2 is movably disposed on the stator support plate and moves a certain distance along the circumferential direction of the annular support plate; several sets of nozzle blades are evenly distributed circumferentially throughout the pre-swirl nozzle structure; the blade back solid shell 2 of each set of nozzle blades forms an airflow channel for the pre-swirl nozzle between it and the blade body 1 of another adjacent nozzle blade; the pre-swirl nozzle structure is annular; as shown Figure 1 (a) shows the initial state of the nozzle blades. Figure 1 (b) is the state after the nozzle blades are adjusted.

[0012] In the technical solution of this invention, during the movement of the solid shell on the back of the blade along the circumferential direction, the leading edge of the solid shell on the back of the blade always remains in contact with the leading edge of the blade body, ensuring that the solid shell on the back of the blade and the blade body form an effectively connected solid domain on the windward surface, avoiding gaps between them that could cause air leakage; at the same time, it meets the flight requirements of military aero engines for a wide airspace and a wide speed range (the range of flight altitude and flight speed is increased).

[0013] The solid shell 2 on the back of the blade moves along the circumferential direction of the annular support plate between the bottom support plate 3 and the top L-shaped support plate 4; during the circumferential movement of the solid shell 2 on the back of the blade, the leading edge of the solid shell 2 on the back of the blade always remains in contact with the leading edge of the blade body 1; such as Figure 2 (a) shows the initial state of the nozzle blades. Figure 2 (b) shows the state after the nozzle blades have been adjusted;

[0014] In this invention, during the circumferential movement of the solid shell 2 on the back of the blade, the leading edge of the solid shell 2 remains in contact with the leading edge of the blade body 1. This ensures that the solid shell 2 and the blade body 1 form an effectively connected solid domain on the windward side, preventing gaps between them that could cause air leakage. Preferably, the moving distance of the solid shell is related to the length of its leading edge, such as... Figure 4 As shown in (a), 2A is the leading edge of the solid shell on the back of the blade, and L2 is the length of the leading edge of the solid shell on the back of the blade; the maximum moving distance of the solid shell on the back of the blade is its leading edge length; the leading edge of the blade body and the leading edge of the solid shell on the back of the blade constitute the solid wall surface of the blade's windward side, as shown in (a). Figure 1 As shown, S1 and S2 are both solid walls on the windward side of the blade; the outer peripheral wall of the solid shell on the back of each set of nozzle blades forms an airflow channel for the pre-swirling nozzle between it and the inner peripheral wall of the blade body of the adjacent set of nozzle blades, as shown. Figure 4 As shown in (b), 1A is the leading edge of the nozzle blade body, and L1 is the length of the leading edge of the nozzle blade body.

[0015] like Figure 6 As shown, H is the trailing edge length, D is the thickness of the solid shell on the back of the blade, R1 is the leading edge arc of the blade body, R2 is the blade basin arc of the blade body, R3 is the back arc of the solid shell on the back of the blade, θ1 is the blade basin angle, and θ2 is the back angle.

[0016] The leading edge of the blade body forms a certain arc with the leaf base of the blade body, which is defined as the leading edge arc of the blade body;

[0017] The ratio of the leading edge curvature of the leaf body to the leaf base curvature of the leaf body to the back curvature of the leaf underside is 2:15:12.

[0018] The inclination angle between the blade basin of the blade body and the trailing edge is defined as the blade basin inclination angle; the inclination angle between the solid thin shell on the blade back and the trailing edge is defined as the blade back inclination angle; the ratio of the blade back inclination angle to the blade basin inclination angle is: 10:11;

[0019] When the nozzle blade is stationary, the ratio of the nozzle blade height: the leading edge length of the blade body: the trailing edge length is: 6:9:8;

[0020] Furthermore, the ratio of the leading edge length of the solid thin shell on the blade back to the thickness D of the solid thin shell on the blade back is: 7.5:1; the ratio of the leading edge length of the solid thin shell on the blade back to the leading edge length of the blade body is: 1:2; the sum of the width of the solid on the windward side of the blade and the width of the air flow channel inlet is a constant value, and the air flow channel inlet is at the positions shown by T1 and T2 in Figure 1 ; the intake area of the air flow channel inlet is linearly negatively correlated with the circumferential movement distance of the solid thin shell on the blade back. The greater the movement distance of the solid thin shell on the blade back, the smaller the flow area.

[0021] Furthermore, the intake area of the air flow channel inlet is linearly negatively correlated with the circumferential movement distance of the solid thin shell on the blade back, and the expression is:

[0022] Af = h*(T1 - ΔS)

[0023] Where, Af is the intake area, h is the blade height, T1 is the intake width of the original nozzle, and ΔS is the circumferential movement distance of the solid thin shell on the blade back.

[0024] Furthermore, the sum of the width of the solid on the windward side of the blade and the width of the air flow channel inlet is equal to the sum of the width of the solid on the windward side of the initial blade and the width of the air flow channel inlet, that is, T1 + S1 = T2 + S2 = Constant, as Figure 1 ;

[0025] Since the blade body 1 is fixed, the sum of the width of the air flow channel inlet and the effective width of the solid on the windward side of the blade is a constant value, that is, T1 + S1 = T2 + S2 = Constant. When the blade height remains unchanged, the channel area is linearly positively correlated with the channel width; when the solid thin shell 2 on the blade back moves a certain distance circumferentially along the annular support plate, both the air flow inlet channel width and the channel width between adjacent blades become smaller, and the effective width of the solid on the windward side of the blade becomes larger, that is, T2 < T1 and S2 > S1. At this time, both the inlet flow area of the air flow entering a pre-whirl nozzle blade and the channel area between another adjacent pre-whirl nozzle blade become smaller. Therefore, the amount of cold air entering the pre-whirl nozzle decreases; at the same time, during the movement of the solid thin shell 2 on the blade back, the two sides of the air flow channel can maintain the aerodynamic blade profile design of the blade basin and blade back, avoiding additional aerodynamic losses.

[0026] When the solid thin shell on the back of the blade moves a certain distance circumferentially in the technical solution of the present invention, both the inlet width of the air flow channel and the flow channel width between adjacent blades become smaller, and the effective solid width of the windward side of the blade becomes larger, that is, T2 < T1 and S2 > S1. At this time, both the inlet flow area of the air flow entering the pre-swirl nozzle and the flow channel area between adjacent blades become smaller. Therefore, the amount of cold air entering the pre-swirl nozzle decreases. At the same time, during the movement of the solid thin shell on the back of the blade, the aerodynamic blade profiles of the blade basin and the back of the blade can be maintained on both sides of the air flow channel, avoiding additional aerodynamic losses.

[0027] The solid thin shell 2 on the back of the blade of the present invention realizes circumferential movement through the action of the link mechanism. For the convenience of display, Figure 2 the top L-shaped support plate 4 and the micro servo motor 5 are hidden; the link mechanism is composed of a driving arm 6 and a follower arm 7. Among them, one end of the driving arm 6 is connected to the micro servo motor 5, and the other end is connected to the follower arm 7; one end of the follower arm 7 is connected to the driving arm 6, and the other end is connected to the mounting seat 8; the mounting seat 8 is fixedly installed at the leading edge of the solid thin shell 2 on the back of the blade; when the micro servo motor 5 works, the driving arm 6 deflects a certain angle, and the link mechanism acts to make the follower arm 7 push the solid thin shell 2 on the back of the blade to move a certain distance circumferentially, thereby realizing the adjustment of the cold air volume. As Figure 3 shown, only one of the multiple blade units in the full ring is included in the figure, where Figure 3 (a) is a three-dimensional view of the pre-swirl nozzle structure, Figure 3 (b) is a front view of the pre-swirl nozzle structure, Figure 3 (c) is a right view of the pre-swirl nozzle structure.

[0028] The groove formed in the middle of the top L-shaped support plate 4 is used to place the micro servo motor 5. The front edges of the bottom support plate 3 and the top L-shaped support plate 4 are respectively connected to the static wall surface 9 of the combustion chamber inner ring; the bottom support plate 3 and the top L-shaped support plate 4 are only schematic diagrams within a fan segment period near the nozzle. The stator support plate of the pre-swirl nozzle is connected to the static wall surface of the combustion chamber inner ring.

[0029] Preferably, the length ratio of the driving arm to the follower arm is: 2.2:1.

[0030] When the micro servo motor in the technical solution of the present invention works, the driving arm deflects a certain angle, and the link mechanism acts to make the follower arm push the solid thin shell on the back of the blade to move a certain distance circumferentially, thereby realizing the adjustment of the cold air volume.

[0031] In the technical solution of the present invention, the adjustment of the cold air volume is realized by adjusting the relative position of the solid thin shell on the back of the blade and the blade body; when the solid thin shell on the back of the blade moves a certain distance in the circumferential direction, the effective solid formed by the solid thin shell on the back of the blade and the blade body (such as Figure 1The increased frontal area (solid wall area shown in S1 and S2) and the smaller inlet flow area of ​​the pre-swirl nozzle and the flow channel area between adjacent blades result in a smaller amount of cold air entering the pre-swirl nozzle. Simultaneously, during the movement of the solid shell on the blade back, the aerodynamic airfoil design of the blade base and blade back is maintained on both sides of the airflow channel, avoiding additional aerodynamic losses.

[0032] This invention employs a pre-swirl cooling air system with an adjustable pre-swirl nozzle design. During the switching of variable cycle engine modes, when the aerodynamic parameters of the air system following the main flow components undergo drastic changes, the pre-swirl nozzle designed in this invention will respond accordingly. While ensuring key functional indicators of the air system (such as bladed disk cooling, rim sealing, and axial force control), the bleed air volume is adjusted as needed to improve the performance and safety of the variable cycle engine across the entire flight envelope. For example, if excessively high exhaust temperatures occur during the switching process, potentially burning the blades, increasing the bleed air volume can reduce the risk of blade erosion and turbine disk breakage. Similarly, if abnormal axial force occurs during the switching process, the pressure in the front and rear chambers can be adjusted through nozzle regulation, suppressing axial force deviations to a certain extent.

[0033] Compared with the prior art, the present invention has at least the following beneficial effects:

[0034] (1) This invention proposes a blade-shaped pre-swirl nozzle structure with adjustable flow area. By working together with a micro servo motor and a linkage mechanism, the relative position of the solid thin shell on the back of the blade and the main body of the blade is adjusted, thereby changing the airflow channel area of ​​the pre-swirl nozzle and effectively regulating the amount of cold air.

[0035] (2) In the process of effectively adjusting the amount of cold air, the airflow channel can maintain the aerodynamic blade design of the blade basin and blade back on both sides, thus avoiding additional aerodynamic losses.

[0036] (3) The adjustable flow area blade-shaped pre-swirl nozzle structure proposed in the technical solution of the present invention enables different amounts of cooling air to be provided to the pre-swirl cooling air system under different operating conditions, so as to reduce the overall fuel consumption rate of the gas turbine engine under all operating conditions.

[0037] (4) The blade-shaped pre-swirl nozzle structure proposed in this invention can also be adjusted when the variable cycle engine performs component adjustment and mode switching in the main flow path, thereby improving the thrust and safety under the entire flight envelope.

[0038] (5) The present invention achieves the adjustment of the nozzle flow area without changing the already optimized aerodynamic design of the pre-rotating nozzle profile geometry parameters. The adjustment process maintains the aerodynamic profile design and avoids additional aerodynamic losses. Attached Figure Description

[0039] The accompanying drawings are for illustrative purposes only and are not intended to limit the scope of the invention.

[0040] Figure 1 (a) is a cross-sectional schematic diagram showing the relative positions of the blade body, the solid shell on the back of the blade, and the airflow channel in the initial state of the nozzle blade of the present invention; Figure 1 (b) is a cross-sectional schematic diagram showing the relative positions of the blade body, the solid shell on the back of the blade, and the airflow channel in the state after the nozzle blade of the present invention has been adjusted;

[0041] Figure 2 (a) is a three-dimensional schematic diagram of the relative positions of the blade body and the solid thin shell on the back of the blade in the initial state of the nozzle blade of the present invention; Figure 2 (b) is a three-dimensional schematic diagram of the relative position of the blade body and the solid thin shell on the back of the blade after the nozzle blade of the present invention has been adjusted.

[0042] Figure 3 (a) A perspective view of the pre-rotating nozzle structure after the nozzle blades of the present invention have been adjusted; Figure 3 (b) Front view of the pre-rotating nozzle structure after the nozzle blades of the present invention have been adjusted; Figure 3 (c) Right view of the pre-rotating nozzle structure after the nozzle blades of the present invention have been adjusted;

[0043] Figure 4 (a) is a planar schematic diagram of the relative positions of the blade body and the solid thin shell on the back of the blade in the initial state of the nozzle blade of the present invention; Figure 4 (b) is a planar schematic diagram of the relative positions of the blade body and the solid thin shell on the back of the blade in the state after the nozzle blade of the present invention has been adjusted;

[0044] Figure 5 This is a schematic diagram showing the installation position of the blade-shaped pre-swirl nozzle structure of the present invention;

[0045] Figure 6 This is a schematic diagram of the initial state structure of the nozzle blade in the blade-shaped pre-swirl nozzle structure of the present invention.

[0046] Attached Figures: 1-Blade body, 1A-Leading edge of blade body, 2-Solid shell on blade back, 2A-Leading edge of solid shell on blade back, 3-Bottom support plate, 4-Top L-shaped support plate, 5-Miniature servo motor, 6-Drive arm, 7-Follower arm, 8-Mounting base, 9-Annular stator wall in combustion chamber, T1-Initial airflow channel inlet width of blade, T2-Initial airflow channel inlet width of blade after adjustment, S1-Initial solid width of blade on the windward side, S2-Initial solid width of blade on the windward side after adjustment, H-Blade trailing edge length, D-Thickness of solid shell on blade back, R1-Radius of leading edge arc of blade body, R2-Arch of blade body, R3-Arch of blade back solid shell, θ1-Arch angle of blade box, θ2-Arch angle of blade back. Detailed Implementation

[0047] To better understand the above-described objectives, features, and advantages of the present invention, the invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. It should be noted that, unless otherwise specified, the embodiments of the present invention and the features thereof can be combined with each other. Furthermore, the present invention can be implemented in other ways different from those described herein; therefore, the scope of protection of the present invention is not limited to the specific embodiments disclosed below.

[0048] A specific embodiment of the present invention, such as Figure 1-3 This invention discloses a blade-shaped pre-swirl nozzle structure with adjustable flow area. To illustrate the effectiveness of the method proposed in this invention, the following detailed description of the above technical solution is provided through a specific embodiment. The specific implementation steps are as follows:

[0049] The present invention provides a blade-shaped pre-swirl nozzle structure with adjustable flow area. The blade-shaped pre-swirl nozzle structure includes: nozzle blades, bottom support plate (3) and top support plate (4); the nozzle blades include blade body (1) and blade back solid thin shell (2);

[0050] The blade body is fixedly mounted on the bottom support plate; the blade back solid shell (2) is movably mounted between the bottom support plate and the top support plate.

[0051] Preferably, both the bottom support plate 3 and the top L-shaped support plate 4 are annular support plates, and multiple sets of nozzle blades are arranged circumferentially along the inner plate surface of the bottom support plate (3) and the top support plate (4).

[0052] The outer peripheral wall of the solid thin shell on the back of each set of nozzle blades forms an airflow channel between it and the inner peripheral wall of the blade body of the adjacent set of nozzle blades; such as Figure 1 As shown; the blade body 1 and the solid thin shell 2 on the back of the blade are horizontally placed between the bottom support plate 3 and the top L-shaped support plate, and the blade body 1 is fixedly connected to the bottom support plate 3 and the top L-shaped support plate respectively.

[0053] Preferably, the bottom support plate and the top L-shaped support plate are stator support plates; the blade body 1 is fixedly installed on the stator support plate, and the blade back solid shell 2 is movably disposed on the stator support plate and moves a certain distance along the circumferential direction of the annular support plate; several sets of nozzle blades are evenly distributed circumferentially throughout the pre-swirl nozzle structure; the blade back solid shell 2 of each set of nozzle blades forms an airflow channel for the pre-swirl nozzle between it and the blade body 1 of another adjacent nozzle blade; the pre-swirl nozzle structure is annular; as shown Figure 1 (a) shows the initial state of the nozzle blades. Figure 1 (b) is the state after the nozzle blades are adjusted.

[0054] In the technical solution of this invention, during the movement of the solid shell on the back of the blade along the circumferential direction, the leading edge of the solid shell on the back of the blade always remains in contact with the leading edge of the blade body, ensuring that the solid shell on the back of the blade and the blade body form an effectively connected solid domain on the windward surface, avoiding gaps between them that could cause air leakage; at the same time, it meets the flight requirements of military aero engines for a wide airspace and a wide speed range (the range of flight altitude and flight speed is increased).

[0055] The solid shell 2 on the back of the blade moves along the circumferential direction of the annular support plate between the bottom support plate 3 and the top L-shaped support plate 4; during the circumferential movement of the solid shell 2 on the back of the blade, the leading edge of the solid shell 2 on the back of the blade always remains in contact with the leading edge of the blade body 1; such as Figure 2 (a) shows the initial state of the nozzle blades. Figure 2 (b) shows the state after the nozzle blades have been adjusted;

[0056] In this invention, during the circumferential movement of the solid shell 2 on the back of the blade, the leading edge of the solid shell 2 remains in contact with the leading edge of the blade body 1. This ensures that the solid shell 2 and the blade body 1 form an effectively connected solid domain on the windward side, preventing gaps between them that could cause air leakage. Preferably, the moving distance of the solid shell is related to the length of its leading edge, such as... Figure 4 As shown in (a), 2A is the leading edge of the solid shell on the back of the blade, and L2 is the length of the leading edge of the solid shell on the back of the blade; the maximum moving distance of the solid shell on the back of the blade is its leading edge length; the leading edge of the blade body and the leading edge of the solid shell on the back of the blade constitute the solid wall surface of the blade's windward side, as shown in (a). Figure 1 As shown, S1 and S2 are both solid walls on the windward side of the blade; the outer peripheral wall of the solid shell on the back of each set of nozzle blades forms an airflow channel for the pre-swirling nozzle between it and the inner peripheral wall of the blade body of the adjacent set of nozzle blades, as shown. Figure 4 As shown in (b), 1A is the leading edge of the nozzle blade body, and L1 is the length of the leading edge of the nozzle blade body.

[0057] like Figure 6 As shown, H is the trailing edge length, D is the thickness of the solid shell on the back of the blade, R1 is the leading edge arc of the blade body, R2 is the blade basin arc of the blade body, R3 is the back arc of the solid shell on the back of the blade, θ1 is the blade basin angle, and θ2 is the back angle.

[0058] The leading edge of the blade body forms a certain arc with the leaf base of the blade body, which is defined as the leading edge arc of the blade body;

[0059] The ratio of the leading edge curvature of the leaf body to the leaf base curvature of the leaf body to the back curvature of the leaf underside is 2:15:12.

[0060] The inclination angle between the blade basin of the blade body and the trailing edge is defined as the blade basin inclination angle; the inclination angle between the solid thin shell of the blade back and the trailing edge is defined as the blade back inclination angle; the ratio of the blade back inclination angle to the blade basin inclination angle is: 10:11;

[0061] When the nozzle blade is stationary, the ratio of the nozzle blade height: the leading edge length of the blade body: the trailing edge length is: 6:9:8;

[0062] Furthermore, the ratio of the leading edge length of the solid thin shell of the blade back to the thickness D of the solid thin shell of the blade back is: 7.5:1; the ratio of the leading edge length of the solid thin shell of the blade back to the leading edge length of the blade body is: 1:2; the sum of the width of the solid on the windward side of the blade and the width of the air flow channel inlet is a constant value, and the air flow channel inlet is at the positions shown by T1 and T2 in Figure 1 ; the intake area of the air flow channel inlet is linearly negatively correlated with the circumferential movement distance of the solid thin shell of the blade back. The greater the movement distance of the solid thin shell of the blade back, the smaller the flow area.

[0063] Furthermore, the intake area of the air flow channel inlet is linearly negatively correlated with the circumferential movement distance of the solid thin shell of the blade back, and the expression is:

[0064] Af = h*(T1 - ΔS)

[0065] Where, Af is the intake area, h is the blade height, T1 is the intake width of the original nozzle, and ΔS is the circumferential movement distance of the solid thin shell of the blade back.

[0066] Furthermore, the sum of the width of the solid on the windward side of the blade and the width of the air flow channel inlet is equal to the sum of the width of the solid on the windward side of the initial blade and the width of the air flow channel inlet, that is, T1 + S1 = T2 + S2 = Constant, as Figure 1 ;

[0067] Since the blade body 1 is fixed, the sum of the width of the air flow channel inlet and the effective width of the solid on the windward side of the blade is a constant value, that is, T1 + S1 = T2 + S2 = Constant. When the blade height remains unchanged, the channel area is linearly positively correlated with the channel width; when the solid thin shell 2 of the blade back moves a certain distance circumferentially along the annular support plate, both the air flow inlet channel width and the channel width between adjacent blades become smaller, and the effective width of the solid on the windward side of the blade becomes larger, that is, T2 < T1 and S2 > S1. At this time, both the inlet flow area of the air flow entering a pre-whirl nozzle blade and the channel area between another adjacent pre-whirl nozzle blade become smaller. Therefore, the amount of cold air entering the pre-whirl nozzle decreases; at the same time, during the movement of the solid thin shell 2 of the blade back, the two sides of the air flow channel can maintain the aerodynamic blade profile design of the blade basin and blade back, avoiding additional aerodynamic losses.

[0068] In the technical solution of the present invention, when the solid thin shell on the back of the blade moves a certain distance circumferentially, both the width of the air flow channel inlet and the width of the flow channel between adjacent blades become smaller, and the effective solid width on the windward side of the blade becomes larger, that is, T2 < T1 and S2 > S1. At this time, both the inlet flow area of the air flow into the pre-swirl nozzle and the flow channel area between adjacent blades become smaller, so the amount of cold air entering the pre-swirl nozzle decreases. At the same time, during the movement of the solid thin shell on the back of the blade, the airfoil design of the blade basin and the blade back can be maintained on both sides of the air flow channel, avoiding additional aerodynamic losses.

[0069] The solid thin shell 2 on the back of the blade of the present invention realizes circumferential movement through the action of the link mechanism. For the convenience of display, Figure 2 the top L-shaped support plate 4 and the micro servo motor 5 are hidden; the link mechanism is composed of a driving arm 6 and a follower arm 7. Among them, one end of the driving arm 6 is connected to the micro servo motor 5, and the other end is connected to the follower arm 7; one end of the follower arm 7 is connected to the driving arm 6, and the other end is connected to the mounting seat 8; the mounting seat 8 is fixedly installed at the leading edge of the solid thin shell 2 on the back of the blade; when the micro servo motor 5 works, the driving arm 6 deflects a certain angle, and the link mechanism acts to make the follower arm 7 push the solid thin shell 2 on the back of the blade to move a certain distance circumferentially, thereby realizing the adjustment of the cold air volume. As Figure 3 shown, only one of the multiple blade units in the full ring is included in the figure, where, Figure 3 (a) is a three-dimensional view of the pre-swirl nozzle structure, Figure 3 (b) is a front view of the pre-swirl nozzle structure, Figure 3 (c) is a right view of the pre-swirl nozzle structure.

[0070] The groove formed in the middle of the top L-shaped support plate 4 is used to place the micro servo motor 5. The front edges of the bottom support plate 3 and the top L-shaped support plate 4 are respectively connected to the static wall surface 9 of the inner ring of the combustion chamber; the bottom support plate 3 and the top L-shaped support plate 4 are only schematic diagrams within a fan segment period near the nozzle, and the stator support plate of the pre-swirl nozzle is connected to the static wall surface of the inner ring of the combustion chamber.

[0071] Preferably, the length ratio of the driving arm to the follower arm is: 2.2:1.

[0072] When the micro servo motor in the technical solution of the present invention works, the driving arm deflects a certain angle, and the link mechanism acts to make the follower arm push the solid thin shell on the back of the blade to move a certain distance circumferentially, thereby realizing the adjustment of the cold air volume.

[0073] In the technical solution of the present invention, the adjustment of the cold air volume is achieved by adjusting the relative position of the solid thin shell on the back of the blade and the blade body; when the solid thin shell on the back of the blade moves a certain distance along the circumferential direction, the effective solid formed by the solid thin shell on the back of the blade and the blade body (such as Figure 1The increased frontal area (solid wall area shown in S1 and S2) and the smaller inlet flow area of ​​the pre-swirl nozzle and the flow channel area between adjacent blades result in a smaller amount of cold air entering the pre-swirl nozzle. Simultaneously, during the movement of the solid shell on the blade back, the aerodynamic airfoil design of the blade base and blade back is maintained on both sides of the airflow channel, avoiding additional aerodynamic losses.

[0074] This invention employs a pre-swirl cooling air system with an adjustable pre-swirl nozzle design. During the switching of variable cycle engine modes, when the aerodynamic parameters of the air system following the main flow components undergo drastic changes, the pre-swirl nozzle designed in this invention will respond accordingly. While ensuring key functional indicators of the air system (such as bladed disk cooling, rim sealing, and axial force control), the bleed air volume is adjusted as needed to improve the performance and safety of the variable cycle engine across the entire flight envelope. For example, if excessively high exhaust temperatures occur during the switching process, potentially burning the blades, increasing the bleed air volume can reduce the risk of blade erosion and turbine disk breakage. Similarly, if abnormal axial force occurs during the switching process, the pressure in the front and rear chambers can be adjusted through nozzle regulation, suppressing axial force deviations to a certain extent.

[0075] In the implementation process, at least one of the solid blades of the pre-swirl nozzle with adjustable flow area according to the present invention is included in all the solid blades of the pre-swirl nozzle ring, so that the cooling air volume can be adjusted. The arrangement is as follows: several blade-shaped pre-swirl nozzle structures with adjustable flow area according to the design features of the present invention are evenly arranged in the circumferential direction. This configuration can balance the flexibility of cooling air volume adjustment with the complexity of component installation.

[0076] Example 1

[0077] The pre-swirl nozzle has a total of 48 solid blades in the entire ring. Among them, an adjustable pre-swirl nozzle structure with the design features of the present invention is arranged every 45° in the circumference, that is, 8 adjustable pre-swirl nozzle structures with the design features of the present invention are evenly arranged in the circumference. The remaining 40 solid blades are the original non-adjustable configuration.

[0078] The blade body 1 and the blade back solid shell 2 are located between the bottom support plate 3 and the top L-shaped support plate 4. The blade body 1 is fixed to the support plate, while the blade back solid shell 2 can move circumferentially between the support plates. A miniature servo motor 5, placed in the middle groove of the top L-shaped support plate 4, provides deflection power to the drive arm 6. The drive arm 6 and the follower arm 7 form a linkage mechanism, which actuates the circumferential movement of the blade back solid shell 2. By adjusting the moving distance of the blade back solid shell 2, the size of the airflow area of ​​the pre-swirl nozzle is changed, thereby effectively regulating the airflow rate entering the pre-swirl nozzle. This allows for different amounts of cooling air to be provided to the pre-swirl cooling system under different operating conditions, thereby reducing the overall fuel consumption rate of the gas turbine engine under all operating conditions.

[0079] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any changes or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in the present invention should be included within the scope of protection of the present invention.

Claims

1. A pre-swirl nozzle structure with adjustable flow area, characterized in that, It includes a nozzle blade, a bottom support plate (3) and a top support plate (4); the nozzle blade includes a blade body (1) and a solid thin shell on the back of the blade (2). The blade body is fixedly mounted on the bottom support plate; the blade back solid shell (2) is movably mounted between the bottom support plate and the top support plate. Both the bottom support plate (3) and the top support plate (4) are annular support plates, and multiple sets of nozzle blades are arranged circumferentially along the inner plate surface of the bottom support plate (3) and the top support plate (4); The outer peripheral wall of the solid thin shell on the back of each set of nozzle blades forms an airflow channel for the pre-swirling nozzle between the inner peripheral wall of the blade body of the adjacent set of nozzle blades. The leaf-back solid shell (2) moves along the circumferential direction of the annular support plate between the bottom support plate (3) and the top support plate (4); During the movement of the solid shell (2) on the back of the blade along the circumferential direction, the leading edge of the solid shell (2) on the back of the blade always keeps in contact with the leading edge of the blade body (1), forming a connected solid domain on the windward side of the solid shell (2) on the back of the blade and the blade body (1).

2. The blade-shaped pre-swirl nozzle structure according to claim 1, characterized in that, The ratio of the leading edge curvature of the leaf body (1): the leaf basin curvature of the leaf body (1): the back curvature of the leaf back solid shell (2) is 2:15:

12.

3. The blade-shaped pre-swirl nozzle structure according to claim 1, characterized in that, The ratio of the leading edge length of the leaf back solid shell (2) to the thickness D of the leaf back solid shell is 7.5:

1.

4. The blade-shaped pre-swirl nozzle structure according to claim 1, characterized in that, The ratio of the leading edge length of the solid shell (2) on the back of the leaf to the leading edge length of the blade body (1) is 1:

2.

5. The blade-shaped pre-swirl nozzle structure according to claim 1, characterized in that, The inlet area of ​​the airflow channel is linearly negatively correlated with the circumferential movement distance of the solid thin shell on the back of the blade.

6. The blade-shaped pre-swirl nozzle structure according to claim 5, characterized in that, The inlet area of ​​the airflow channel is linearly negatively correlated with the circumferential movement distance of the solid thin shell on the back of the blade, as expressed by: Af=h*(T1-ΔS) Where Af is the inlet area, h is the blade height, T1 is the inlet width of the original nozzle, and ΔS is the distance the solid shell on the back of the blade moves circumferentially.

Images