Novel flap type turbine blade structure and variable cycle engine

Abstract

The invention relates to the technical field of aero-engine turbine blades or heavy-duty gas turbine blades, in particular to a novel flap type turbine blade structure and a variable cycle engine, and the novel flap type turbine blade structure comprises a connecting assembly, a cover plate, a flap blade, an end wall and a front edge fixed blade. The flap blade penetrates through the end wall and moves in the end wall, the front edge fixed blade is seamlessly connected with the end wall, and the combined action of a cover plate and a sealing ring above the flap blade is matched, so that the blade top parts and the blade bottom parts of the front edge fixed blade and the flap blade are gapless, and the blade gap leakage vortex is effectively avoided; and through the sealing effect of the sealing ring and tightly-sealed cold air, high-temperature gas leakage at the seam of the end wall is effectively prevented. The variable-cycle turbine blade solves the problems that an existing variable-cycle turbine blade is large in total pressure loss and low in safety and stability due to backflow of high-temperature fuel gas caused by a blade top gap and a blade bottom gap, the oil consumption rate of an aero-engine is reduced, and economic benefits are improved.

Description

Technical Field

[0001] The present invention relates to the technical field of aircraft engine turbine blades or heavy-duty gas turbine turbine blades, and specifically to a novel flap-type turbine blade structure and a variable cycle engine, and in particular to a novel flap-type turbine blade structure and a variable cycle engine suitable for a variable cycle engine. Background Art

[0002] Variable cycle engines have excellent airflow regulation capabilities, good inherent cycle performance and low fuel consumption. They are widely used in many fields, especially in the aviation and energy industries. Variable cycle turbines are an important part of variable cycle engines, and variable cycle turbine blades have been proven to be the best variable cycle turbine regulation method. In order to improve the efficiency of variable cycle engines under non-design conditions, scientists are actively conducting research and improvements on variable cycle turbine blades.

[0003] See also Figure 1 In the traditional variable cycle turbine blade dynamic adjustment process, in order to ensure that the variable cycle turbine blade dynamic adjustment process can proceed smoothly, there is a gap between the blade and the end wall. Common variable cycle turbine devices, blade height h v,t Less than end wall height h e,t There are gaps between the blade tip and blade bottom and the end wall. Due to the pressure difference between the suction surface and the pressure surface, a leakage flow is formed in the gap. The leakage flow mixes with the mainstream to form a leakage vortex, which causes losses and has an adverse effect on the turbine. High-temperature combustion gas will leak back through the end wall gap, increase the thermal stress of the hot end components of the turbine, and pose a great threat to the safe and stable operation of the turbine. Summary of the invention

[0004] In view of the problems of large total pressure loss and low safety and stability caused by backflow of high-temperature combustion gas in variable cycle turbine blades in the prior art, the present invention provides a novel flap-type turbine blade structure and a variable cycle engine.

[0005] In order to achieve the above object, the present invention adopts the following technical solutions: The present invention provides a novel flap-type turbine blade structure, comprising a connecting assembly, a cover plate, a flap blade, an end wall and a leading edge fixed blade; one end of the connecting assembly is connected to a rocker arm of an engine, and the other end is connected to the cover plate and the flap blade in sequence; an end wall slit is provided on the end wall, and the flap blade passes through the end wall slit and moves freely in the end wall slit; a sealing ring is provided on the end wall along the outer side of the end wall slit; the leading edge fixed blade is seamlessly connected to a side of the end wall away from the cover plate; and sealed cold air is introduced into a side of the cover plate close to the connecting assembly.

[0006] Optionally, the shape of the end wall slit is the same as the shape of a projection profile swept during the movement of the flap blade.

[0007] Optionally, the area of ​​the end wall slot is larger than the projected contour area swept during the movement of the flap blade.

[0008] Optionally, an end wall groove is provided on the end surface of the end wall close to the cover plate for installing a sealing ring.

[0009] Optionally, the radius of the end wall groove is equal to the radius of the sealing ring, and the radius of the sealing ring is equal to the distance between the cover plate and the end wall.

[0010] Optionally, the side where the end wall is connected to the leading edge fixed blade is an I-shaped structure.

[0011] Optionally, the area of ​​the cover plate is larger than the area surrounded by the sealing ring, and the cover plate always covers the area surrounded by the sealing ring during the movement of the flap blade.

[0012] Optionally, the height of the flap blade is greater than the height of the end wall.

[0013] Optionally, the sealing ring is made of high temperature resistant ceramic woven flexible fiber material.

[0014] The present invention also provides a variable cycle engine, comprising the above-mentioned novel flap-type turbine blade structure.

[0015] Compared with the prior art, the present invention has the following beneficial effects: The invention discloses a novel flap-type turbine blade structure, comprising a connecting assembly, a cover plate, a flap blade, an end wall and a leading edge fixed blade; the connecting assembly is connected to a rocker arm of an engine, so that the movement of the rocker arm drives the connecting assembly to move, and the flap blade is driven to move through the connection of the connecting assembly with the cover plate and the flap blade; an end wall slit is provided on the end wall, so that the flap blade passes through the end wall slit and moves freely in the end wall slit; since the blade tip portions of the leading edge fixed blade and the flap blade have no blade tip gap, the generation of blade gap leakage vortex is effectively avoided, thereby reducing the blade cascade channel The high-temperature combustion gas passes through the leading edge fixed blades and the flap blades in turn. Due to the end wall slits on the end wall, the high-temperature combustion gas in part of the cascade channel will leak from the end wall slits. The setting of the cover plate above the end wall slits can effectively reduce the leakage of high-temperature combustion gas. The sealing ring and the sealed cold air flowing in from the gaps around the cover plate and the gaps around the flap blades can further effectively prevent the leakage of high-temperature combustion gas, which can protect the safe and stable operation of the turbine components, reduce the flow loss in the cascade channel, and improve the turbine efficiency. For aircraft engines, it can greatly reduce its fuel consumption rate and increase its economic benefits.

[0016] The shape of the end wall slit is the same as the shape of the projected contour swept by the flap blade during movement, and the area of ​​the end wall slit is larger than the projected contour area swept by the flap blade during movement to ensure that the flap blade is not hindered by the end wall during movement.

[0017] An end wall groove is arranged on the end surface of the end wall close to the cover plate for installing a sealing ring.

[0018] The radius of the end wall groove is equal to the radius of the sealing ring, which ensures that the sealing ring is installed in place and reliable.

[0019] The radius of the sealing ring is equal to the distance between the cover plate and the end wall, which prevents the mainstream high-temperature combustion gas from leaking from the gap between the cover plate and the end wall, while reducing the influence of the sealing ring on the movement of the flap blades.

[0020] The side where the end wall is connected to the leading edge fixed blade is an I-shaped structure to ensure that the stability and strength of the end wall structure meet the requirements.

[0021] The area of ​​the cover plate is larger than the area surrounded by the sealing ring, and the cover plate always covers the area surrounded by the sealing ring during the movement of the flap blade, so as to ensure that the cover plate always maintains an effective seal with the end wall during the movement, and prevents high-temperature combustion gas leaking from the end wall opening from flowing out from the gap between the end wall and the cover plate, thereby ensuring the safe and stable operation of the turbine.

[0022] The arrangement that the height of the flap blade is greater than the height of the end wall can avoid leakage flow formed in the blade cascade channel due to the existence of the blade top gap and the blade bottom gap, thereby avoiding leakage vortex formed by the mixing of the leakage flow and the mainstream, thereby achieving the purpose of reducing leakage loss.

[0023] The sealing ring is made of high-temperature resistant ceramic woven flexible fiber material, which can ensure the sealing between the cover plate and the end wall while avoiding failure of the sealing ring due to high temperature, thereby ensuring the stability of the sealing.

[0024] The present invention also provides a variable cycle engine, including the above-mentioned novel flap-type turbine blade structure. Through the arrangement of the novel flap-type turbine blade structure, the airflow path is optimized, the aerodynamic performance of the blade surface is enhanced, so that the engine can generate greater thrust under the same fuel consumption and improve combustion efficiency. The engine has a lower fuel consumption rate, a higher fuel heat absorption rate, a low failure rate, higher reliability and a longer service life, thereby having stronger competitiveness, so that it occupies a more important position in the future aviation market. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 It is a two-dimensional cross-sectional schematic diagram of a traditional turbine blade device.

[0026] Figure 2An exploded view of a novel flap-type turbine blade structure of the present invention.

[0027] Figure 3 A two-dimensional end wall structure diagram of the motion process of a novel flap-type turbine blade structure of the present invention.

[0028] Figure 4 It is a cross-sectional schematic diagram of a novel flap-type turbine blade structure of the present invention before movement.

[0029] Figure 5 It is a cross-sectional schematic diagram of a novel flap-type turbine blade structure after movement according to the present invention.

[0030] Among them, 1-connecting assembly, 2-cover plate, 3-flap blade, 4-sealing ring, 5-end wall groove, 6-end wall, 7-leading edge fixed blade, 8-flap blade position at the end of rotation, 9-end wall slit, 10-end wall of traditional turbine structure, 11-blade. DETAILED DESCRIPTION

[0031] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Generally, the components of the embodiments of the present invention described and shown in the drawings here can be arranged and designed in various different configurations.

[0032] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the invention claimed for protection, but merely represents selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0033] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, further definition and explanation thereof is not required in subsequent drawings.

[0034] In the description of the embodiments of the present invention, it should be noted that if the terms "upper", "lower", "horizontal", "inner", etc. indicate an orientation or positional relationship based on the orientation or positional relationship shown in the drawings, or the orientation or positional relationship in which the product of the invention is usually placed when in use, it is only for the convenience of describing the present invention and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention. In addition, the terms "first", "second", etc. are only used to distinguish the description, and cannot be understood as indicating or implying relative importance.

[0035] In addition, if the term "horizontal" appears, it does not mean that the component must be absolutely horizontal, but can be slightly tilted. For example, "horizontal" only means that its direction is more horizontal than "vertical", which does not mean that the structure must be completely horizontal, but can be slightly tilted.

[0036] In the description of the embodiments of the present invention, it is also necessary to explain that, unless otherwise clearly specified and limited, the terms "set", "install", "connect", and "connect" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal connection of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0037] The present invention is further described in detail below in conjunction with specific embodiments, which are intended to explain the present invention rather than to limit it.

[0038] See also Figure 1 In the traditional variable cycle turbine blade dynamic adjustment process, in order to ensure that the variable cycle turbine blade dynamic adjustment process can proceed smoothly, there is a gap between the blade 11 and the end wall 10 of the traditional turbine structure. h v,t Less than end wall height h e,t The blade tip has a blade tip gap, and the blade bottom has a blade bottom gap. Due to the pressure difference between the suction surface and the pressure surface, a leakage flow is formed in the gap. The leakage flow mixes with the mainstream to form a leakage vortex, which causes losses and has an adverse effect on the turbine. High-temperature combustion gas will leak back through the end wall gap, increase the thermal stress of the hot end components of the turbine, and pose a great threat to the safe and stable operation of the turbine.

[0039] To solve the problems existing in the traditional turbine structure, see Figure 2The present invention discloses a novel flap-type turbine blade structure, comprising an end wall 6 and a connecting assembly 1 connected to an engine rocker arm, wherein the connecting assembly 1 is connected with a cover plate 2 and a flap blade 3 in sequence; an end wall slit 9 is provided on the end wall 6, and the flap blade 3 passes through the end wall slit 9 and moves freely in the end wall slit 9, and a leading edge fixed blade 7 is connected to the side of the end wall 6 away from the cover plate 2, and the leading edge fixed blade 7 is seamlessly connected to the end wall 6; a sealing ring 4 is provided on the outer side of the end wall slit 9, and the sealing ring 4 is located between the cover plate 2 and the end wall 6, and is used to seal the gap between the cover plate 2 and the end wall 6; a tightly sealed cold air is passed into the side of the cover plate 2 close to the connecting assembly 1, which is used to assist the sealing ring 2 in sealing the gap between the end wall 6 and the cover plate 2, so as to prevent the high-temperature gas from leaking from the end wall slit 9, thereby ensuring the effective movement of the structure and avoiding the leakage of the high-temperature gas, which affects the stability and service life of the engine.

[0040] Since there is no tip gap between the leading edge fixed blade 7 and the blade top and bottom of the flap blade 3 in the flap-type turbine blade structure, the generation of blade gap leakage vortex is effectively avoided, thereby reducing the flow loss and total pressure loss in the blade cascade channel; the high-temperature combustion gas passes through the leading edge fixed blade 7 and the flap blade 3 successively. Since there is an end wall slit on the end wall 6, the high-temperature combustion gas in part of the blade cascade channel will leak from the end wall slit. The arrangement of the cover plate 2 and the sealing ring 4 above the end wall slit can effectively reduce the leakage of high-temperature combustion gas. The sealing ring 4 and the sealed cold air flowing in from the gaps around the cover plate 2 and the gaps around the flap blades can further effectively prevent the leakage of high-temperature combustion gas, which can protect the safe and stable operation of the turbine components while reducing the flow loss in the blade cascade channel and improving the turbine efficiency.

[0041] Example 1 See also Figure 2 , the present invention discloses a novel flap-type turbine blade structure, comprising an end wall 6 and a connecting assembly 1 connected to an engine rocker arm, wherein the connecting assembly 1 is sequentially connected with a cover plate 2 and a flap blade 3; An end wall slit 9 is provided on the end wall 6, and the flap blade 3 passes through the end wall slit 9 and moves freely in the end wall slit 9. The shape of the end wall slit 9 is the same as the shape of the projected contour swept by the flap blade 3 during the movement, and the area of ​​the end wall slit 9 is larger than the projected contour area swept by the flap blade 3 during the movement, so as to ensure that the movement of the flap blade 3 will not be hindered by the end wall; the side of the end wall 6 away from the cover plate 2 is connected with a leading edge fixed blade 7, and the leading edge fixed blade 7 is seamlessly connected to the end wall 6; an end wall groove 5 is provided on the end surface of the end wall 6 close to the cover plate 2, and a sealing ring 4 is installed in the end wall groove 5, and the end wall groove 5 surrounds the end wall slit 9; and a tightly sealed cold air is passed through the side of the cover plate 2 close to the connecting component 1.

[0042] Example 2 See also Figure 2 The present invention discloses a novel flap-type turbine blade structure, comprising an end wall 6 and a connecting assembly 1 connected to an engine rocker arm, wherein the connecting assembly 1 is sequentially connected with a cover plate 2 and a flap blade 3, wherein the height of the flap blade 3 is greater than the height of the end wall 6; The end wall 6 is provided with an end wall slit 9, and the flap blade 3 passes through the end wall slit 9 and moves freely in the end wall slit 9. The shape of the end wall slit 9 is the same as the shape of the projected contour swept by the flap blade 3 during the movement, and the area of ​​the end wall slit 9 is larger than the area of ​​the projected contour swept by the flap blade 3 during the movement. Preferably, the area of ​​the end wall slit 9 is 1.05 times the area of ​​the projected contour swept by the flap blade 3 during the movement, so as to ensure that the movement of the flap blade 3 will not be hindered by the end wall; the side of the end wall 6 away from the cover plate 2 is connected with a leading edge fixed blade 7, and the leading edge fixed blade 7 is seamlessly connected to the end wall 6; an end wall groove 5 is provided on the end surface of the end wall 6 close to the cover plate 2, and a sealing ring 4 is installed in the end wall groove 5, and the end wall groove 5 surrounds the end wall slit 9. Preferably, the shape of the area surrounded by the end wall groove 5 is consistent with the shape of the end wall slit 9, and the area It is 1.1 times the area of ​​the end wall slit 9; the radius of the end wall groove 5 is equal to the radius of the sealing ring 4, and the radius of the sealing ring 4 is equal to the distance between the cover plate 2 and the end wall 6; the area of ​​the cover plate 2 is larger than the area surrounded by the sealing ring 4, and the cover plate 2 always covers the area surrounded by the sealing ring 4 during the movement of the flap blade 3. Preferably, the shape of the cover plate 2 is similar to the projected shape of the area swept by the flap blade 3 during the movement process, and the area of ​​the cover plate 2 is twice the area of ​​the end wall slit 9, ensuring that the end wall slit 9 is always covered during the entire process of the flap blade movement; the cover plate 2 is passed through a side close to the connecting component 1 with sealed cold air, and the cover plate is passed through the top of the cover plate. The sealed cold air flows in along the gaps around the cover plate 2 and the flap blade 3. After passing through the sealing ring 4, the sealed cold air has a slightly greater pressure than the high-temperature gas pressure, thereby reducing the pressure loss when the cold and hot fluids are mixed, preventing the high-temperature gas from flowing back while reducing the flow loss.

[0043] The working principle of a novel flap-type turbine blade structure provided by the present invention is: See also Figures 3 to 5 , the rocker arm drives the connecting assembly 1 and drives the cover plate 2 and the flap blade 3 to move, see Figure 3 , until the end of the rotation of the flap blade position 8. Figure 4 and Figure 5, the flap blade 3 moves in the end wall slit 9 according to its movement trajectory, and the cover plate 2 always covers the end wall slit 9 during the movement of the flap blade 3. Due to the effect of the sealing ring 4 and the cover plate 2, there is no tip gap between the leading edge fixed blade 7 and the blade tip of the flap blade 3, thereby avoiding the generation of blade gap leakage vortex, thereby reducing the flow loss and total pressure loss in the cascade channel. The high-temperature gas enters the cascade channel from the turbine inlet, passes through the leading edge fixed blade 7 and the flap blade 3 in turn. Since there is an end wall slit 9 on the end wall 6, part of the high-temperature gas in the cascade channel will leak from the end wall slit 9, but under the effect of the cover plate 2 and the sealing ring 4, the leakage of the high-temperature gas can be effectively reduced. With the help of the sealing ring 4 and the sealed cold air flowing in from the gaps around the cover plate 2 and the gaps around the flap blade 3, the purpose of preventing the leakage of the high-temperature gas is achieved, while protecting the safe and stable operation of the turbine components, the flow loss in the cascade channel is reduced, and the turbine efficiency is improved.

[0044] The present invention also provides a variable cycle engine, including the above-mentioned novel flap-type turbine blade structure. Through the arrangement of the novel flap-type turbine blade structure, the airflow path is optimized, the aerodynamic performance of the blade surface is enhanced, so that the engine can generate greater thrust under the same fuel consumption and improve combustion efficiency. The engine has a lower fuel consumption rate, a higher fuel heat absorption rate, a low failure rate, higher reliability and a longer service life, thereby having stronger competitiveness, so that it occupies a more important position in the future aviation market.

[0045] In summary, the present invention provides a novel flap-type turbine blade structure and a variable cycle engine, wherein an end wall slit 9 is provided on the end wall 6 so that the flap blade 3 passes through the end wall 6 and moves in the end wall slit 9, so that the leading edge fixed blade 7 is seamlessly connected to the end wall 6, and the cover plate 2 and the sealing ring 4 above the flap blade 3 cooperate to ensure that there is no gap between the top and bottom parts of the leading edge fixed blade and the flap blade, thereby effectively avoiding the generation of leakage vortices in the blade gap. At the same time, the sealing effect of the sealing ring 4 and the tightly sealed cold air effectively prevents the high-temperature combustion gas from leaking from the end wall slit 9, thereby protecting the safe and stable operation of the turbine components, reducing the flow loss in the blade channel, and improving the turbine efficiency.

[0046] The above description is only a preferred embodiment of the present invention and is not intended to impose any limitation on the technical solution of the present invention. Those skilled in the art should understand that, without departing from the spirit and principles of the present invention, the technical solution can also be subjected to several simple modifications and substitutions, and these modifications and substitutions are also within the scope of protection covered by the claims.

Claims

1. A novel flap-type turbine blade structure, characterized in that: The invention comprises a connecting assembly (1), a cover plate (2), a flap blade (3), an end wall (6) and a leading edge fixed blade (7); one end of the connecting assembly (1) is connected to a rocker arm of an engine, and the other end is connected to the cover plate (2) and the flap blade (3) in sequence; an end wall slit (9) is provided on the end wall (6), and the flap blade (3) passes through the end wall slit (9) and moves freely in the end wall slit (9); a sealing ring (4) is provided on the end wall (6) along the outer side of the end wall slit (9); the leading edge fixed blade (7) is seamlessly connected to a side of the end wall (6) away from the cover plate (2); and a side of the cover plate (2) close to the connecting assembly (1) is passed with sealed cold air.

2. The novel flap-type turbine blade structure according to claim 1 is characterized in that: The shape of the end wall slit (9) is the same as the shape of the projection profile swept by the flap blade (3) during its movement.

3. The novel flap-type turbine blade structure according to claim 2 is characterized in that: The area of ​​the end wall slit (9) is larger than the projected contour area swept by the flap blade (3) during movement.

4. The novel flap-type turbine blade structure according to claim 1 is characterized in that: An end wall groove (5) is provided on the end surface of the end wall (6) close to the cover plate (2) for mounting a sealing ring (4).

5. The novel flap-type turbine blade structure according to claim 4 is characterized in that: The radius of the end wall groove (5) is equal to the radius of the sealing ring (4), and the radius of the sealing ring (4) is equal to the distance between the cover plate (2) and the end wall (6).

6. The novel flap-type turbine blade structure according to claim 1 is characterized in that: The side where the end wall (6) is connected to the leading edge fixed blade (7) is an I-shaped structure.

7. The novel flap-type turbine blade structure according to claim 1 is characterized in that: The area of ​​the cover plate (2) is larger than the area surrounded by the sealing ring (4), and during the movement of the flap blade (3), the cover plate (2) always covers the area surrounded by the sealing ring (4).

8. The novel flap-type turbine blade structure according to claim 1 is characterized in that: The height of the flap blade (3) is greater than the height of the end wall (6).

9. The novel flap-type turbine blade structure according to any one of claims 1 to 8, characterized in that: The sealing ring (4) is made of a high-temperature resistant ceramic braided flexible fiber material.

10. A variable cycle engine, characterized in that: The invention comprises a novel flap-type turbine blade structure as described in any one of claims 1 to 9.

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