A turbine blade with a trailing edge cooled by dual-sided variable-camber split slots on the back of the basin

Abstract

The present invention belongs to the technical field of aero-engine turbine cooling, and relates to a turbine blade whose trailing edge is cooled by slits with variable curvature on both sides of the back of the basin. By alternately providing exhaust slits on both sides of the back of the basin at the trailing edge of the blade, the present invention effectively solves the problem of insufficient cooling on the back of the blade, while also improving the temperature uniformity of the trailing edge and enhancing the overall cooling effect. Furthermore, the present invention changes the cross-sectional shape of the slit channels from a conventional rectangle to a triangle, creating a periodic, dense arrangement, improving the space utilization rate of the trailing edge, and strengthening the structural strength of the trailing edge. Furthermore, the slit cooling structure of the present invention utilizes an optimized design with variable curvature, resulting in reduced internal flow losses and a higher structural load-bearing capacity.

Description

Technical Field

[0001] The invention belongs to the technical field of aero-engine turbine cooling, and relates to a turbine blade whose trailing edge is cooled by using variable-camber splits on both sides of a basin back. Background Art

[0002] Increasing the temperature of the gas flowing into the turbine is one of the most effective ways to improve aircraft engine performance. However, this also results in increasingly high operating temperatures for turbine blades, far exceeding the temperature limits of current materials. Therefore, advanced cooling measures are urgently needed to improve the blades' heat-bearing capacity. Currently, the primary approach to turbine blade cooling is to utilize a hollow design, utilizing enhanced convection transfer within the cooling gas to remove heat and forming an air film upon exiting the blade to isolate it from the gas heat.

[0003] The trailing edge of a turbine blade connects the blade basin and blade back, where high-temperature gases from both sides converge and mix intensely. This region experiences extremely high heat loads and is also the thinnest part of the entire blade structure, making it difficult to form a complex hollow cooling structure. This results in high wall temperatures during operation, making ablation and fracture very likely. This presents a key challenge that needs to be addressed in blade cooling design. Currently, a semi-slit structure with horizontal exhaust from the basin side is commonly used for blade trailing edge cooling. A typical structure is shown in Figures 1(a)-1(c). This structure converts the cooling gas flowing radially in the inner cooling channel 2 of the hollow turbine blade 1 into a chord-wise flow. After enhanced convection cooling on the channel walls and rib structure, the cooling gas is discharged through the rectangular trailing edge horizontal slit channel 3, forming an air film on the basin-side trailing edge to isolate it from heating by the gas. The slit channel centerline 6 exhibits no variation in inclination or curvature for each slit and remains a straight horizontal line when viewed from the main view of the blade. This type of basin-side horizontal exhaust slit cooling structure has deficiencies in terms of flow, heat transfer and strength, which are specifically manifested in the following aspects: First, since the cooling structure has no exhaust slit design on the back side of the blade, the cooling effect on this side is poor, and the overall temperature non-uniformity of the trailing edge is relatively high. Secondly, when the cooling gas is discharged horizontally from the slit channel, it is basically consistent with the flow direction of the gas, so it cannot be deflected radially under the entrainment of the gas, resulting in poor air film coverage. Thirdly, when the cooling gas enters the horizontal slit channel, a drastic flow turn occurs, forming a step flow, resulting in large flow losses. In addition, the horizontal slit structure has a high degree of hollowing of the material on the trailing edge section at the slit opening, lacking effective support and reinforcement, resulting in insufficient strength of the trailing edge structure. Summary of the Invention

[0004] In response to the shortcomings of the existing basin-side horizontal exhaust trailing edge slit cooling technology, a turbine blade with a trailing edge cooled by variable curvature slits on both sides of the basin back is invented. By alternately opening exhaust slits on both sides of the basin back of the blade trailing edge, the problem of insufficient cooling on the back side of the blade can be effectively solved, while improving the temperature uniformity of the blade trailing edge and enhancing the overall cooling effect. In addition, the present invention changes the cross-sectional shape of the slit channel from a conventional rectangle to a triangle, which can form a periodic close arrangement, improve the trailing edge space utilization, and strengthen the trailing edge structural strength. In addition, the slit cooling structure of the present invention adopts an optimized design with variable curvature, so that it has smaller internal flow losses and higher structural load resistance.

[0005] The technical solution of the present invention:

[0006] A turbine blade with a trailing edge cooled by a basin-back double-sided variable camber slit, comprising a hollow turbine blade, an inner cavity cooling air channel, a basin-side variable camber slit channel on the trailing edge, and a back-side variable camber slit channel on the trailing edge. Figure 2(a) and 2(b) As shown;

[0007] The hollow turbine blade is internally provided with an internal cooling air channel for low-temperature cooling gas to flow within the blade, cooling the blade. The trailing edge of the hollow turbine blade is radially alternatingly provided with trailing edge basin-side cambered slit channels and trailing edge back-side cambered slit channels. This allows cooling air in the internal cooling air channel to be alternately discharged through the slit channels to the blade back-side, forming an air film on the outer wall to evenly cool the blade trailing edge area. The total number of trailing edge basin-side cambered slit channels and trailing edge back-side cambered slit channels is i, and their number n varies from 1 to i along the direction from the blade root to the blade tip.

[0008] The structural shape of the trailing edge basin side variable curvature slit channel and the trailing edge back side variable curvature slit channel along the flow direction is controlled by the slit channel centerline. In the blade top view dimension, the projection of the slit channel centerline is a spline curve or an arc curve, such as Figure 2(c) and 2(d)As shown, when it bends toward the trailing edge basin, a smooth, variable-curvature slit channel is formed on the trailing edge basin side, guiding cooling air from the inner cavity cold air channel to the trailing edge basin side, and forming an air film on the basin side wall to isolate the heating of the gas. When it bends toward the trailing edge backside, a smooth, variable-curvature slit channel is formed on the trailing edge backside, guiding cooling air from the inner cavity cold air channel to the trailing edge backside, and forming an air film on the backside wall to isolate the heating of the gas. In the main viewing dimension of the blade, the projection of the slit channel centerline is an arc-shaped curve, an inclined straight line, or a horizontal straight line. Correspondingly, the resulting trailing edge basin-side variable-curvature slit channel and the trailing edge backside variable-curvature slit channel are inclined curved channels, inclined straight channels, or horizontal straight channels in the main viewing direction of the blade, as shown in Figure 2(e). The angles between the tangent directions of the center line of the slit channel at the cold air inlet and the cold air outlet and the horizontal plane are the slit channel inlet angle ∠α and the slit channel outlet angle ∠β, respectively, and ∠α≥∠β. In particular, when ∠α=∠β=0°, the projection of the center line of the slit channel in the main viewing dimension is a horizontal straight line, and the slit is horizontal.

[0009] The present invention adopts a variable curvature design for the center line of the slit channel at different radial positions, and the slit channel inlet angle ∠α and the slit channel outlet angle ∠β show regular changes with the channel number n. The functional relationship is shown in formulas (1) to (2):

[0010]

[0011]

[0012] Where i is the total number of slit channels, α1 and β1 are the inlet angle and outlet angle of the slit channel when n=1, respectively. i and β i are the inlet angle and outlet angle of the splitting channel when n=i, α max and β max are the maximum values of the inlet angle and outlet angle of the splitting channel, respectively, and α1>β1, α i ≥β i , α max >β max The above relationship causes the inlet and outlet angles of the trailing edge exhaust slot channel to increase first and then decrease along the radial direction, and to vary linearly within the upper, middle, and lower sections, respectively. This optimizes the comprehensive performance of the trailing edge structure, including flow, heat transfer, and strength.

[0013] Furthermore, α1 can be 35° to 50°, β1 can be 0 to 25°, and α i It can be 0~20°, β i Can be 0~°, α max It can be 25~45°, β maxIt can be 15 to 35 degrees.

[0014] The cross-sectional shapes of the variable-curvature slit channels on the basin side of the trailing edge and the variable-curvature slit channels on the dorsal side of the trailing edge are isosceles triangles. The cross-sectional triangles of the two are symmetrically staggered and exhibit a periodic close-packed pattern along the radial direction, as shown in Figure 2(f). The cross-sectional characteristics of the triangular channels can be described by the slit channel width w, the slit channel height h, and the apex angle ∠A of the slit channel triangle cross-section. The smaller the slit channel width, the higher the height, and the larger the apex angle ∠A, the flatter the slit channel. Ignoring the influence of the slit channel rounded corners, the relationship between the three can be expressed as the formula:

[0015] h=2w·tan(A / 2)

[0016] The inclined inner walls formed between adjacent variable-camber slit channels on the basin side of the trailing edge and those on the dorsal side of the trailing edge provide support and reinforcement for the trailing edge. Multiple inclined inner walls are connected in sequence along the radial direction, forming a zigzag support structure on the trailing edge cross-section perpendicular to the chord direction. This enhances the blade trailing edge's ability to resist bending, torsion, and centrifugal loads. The thinner the radial slit density, the thicker the wall thickness t between the slit channels, the thicker the zigzag support, and the more pronounced the reinforcement of the trailing edge structure. However, this also reduces the cooling effect on the trailing edge.

[0017] Furthermore, the apex angle ∠A of the triangular cross section of the slit channel can be 110-150°, the width-to-height ratio w / h of the slit channel can be 0.13-0.35, and the ratio t / h of the wall thickness between the slit channels to the height of the slit channels can be 0.1-0.25.

[0018] Beneficial effects of the present invention:

[0019] 1. Improve the cooling effect on the back side of the blade trailing edge:

[0020] Existing trailing edge semi-slit structures exhaust air from the basin side, preventing the cooling air from forming an air film on the back side of the blade, causing the wall surface to reach a higher temperature and insufficient cooling effect. The present invention adopts a basin-back dual-sided variable-curvature slit cooling structure. The slit cooling channels on the back side of the blade not only enhance internal convection heat transfer in the back area, but also form an air film covering the outer wall, isolating it from heating by the combustion gas. This can improve the cooling effect of the back side of the blade trailing edge by approximately 25%, effectively solving the problem of insufficient cooling on the back side of the turbine blade trailing edge and reducing the blade temperature level.

[0021] 2. Improve the temperature unevenness of the blade trailing edge:

[0022] Traditional trailing edge semi-slit cooling structures have poor cooling effectiveness on the back side of the trailing edge, resulting in higher temperatures than the sidewalls. This results in significant temperature non-uniformity, which not only results in higher temperature peaks but also generates significant thermal stress, damaging the trailing edge's strength. The novel slit cooling structure of the present invention alternates slit cooling channels on both sides of the blade backside and utilizes a periodic, densely packed structure with triangular cross-sections. This achieves uniform cooling of both sides of the trailing edge, significantly improving temperature non-uniformity on the trailing edge and reducing thermal stress levels on the blade.

[0023] 3. Increase the air film coverage area and improve the external air film cooling effect:

[0024] First, the basin-back double-sided variable curvature slit cooling structure adopted by the present invention can form an air film coverage on both sides of the basin-back at the trailing edge. Compared with the traditional basin-side exhaust slit structure, the air film coverage area is greatly increased. Secondly, most of the slit channels of the present invention adopt inclined exhaust, and the air film outflow direction is at a certain angle to the gas flow direction. Because of the entrainment effect of the gas on the air film outflow, the cold air is deflected in the flow direction and gradually becomes parallel to the gas flow direction, thereby achieving coverage of part of the area of the slit spacing ribs, so that the actual air film outflow coverage width is greatly increased relative to the slit width. In summary, the trailing edge slit cooling structure of the present invention can greatly increase the cooling air film coverage area, thereby achieving a better external air film cooling effect on the trailing edge wall.

[0025] 4. Improve internal convection heat transfer effect by extending the cold air flow path and increasing the convection heat transfer area:

[0026] The basin back double-sided variable curvature slit cooling structure proposed in the present invention adopts a curved inclined channel, and the channel cross-section adopts a triangular shape, forming a periodic close arrangement in the radial direction, with high space utilization. Compared with the traditional basin side exhaust horizontal slit structure, the flow path of the cold air in the inclined curved channel is longer, and the convection heat exchange between the cold air and the wall is more sufficient. The curved double-sided channel structure greatly increases the internal convection heat exchange area, thereby improving the convection heat exchange effect between the cooling air and the inner wall of the trailing edge cooling channel.

[0027] 5. The optimized design of the slot camber achieves improved drag reduction performance at all radial heights:

[0028] Existing trailing edge slit cooling structures utilize horizontal exhaust. To enter the chord-wise slit cooling channels, radially flowing cooling air must make a nearly 90° turn at high speed within a confined space. This flow generates low-speed vortices at the turn, which not only dissipates energy due to intense friction but also squeezes the main flow, forcing it to undergo additional directional turns and energy losses, resulting in reduced overall engine efficiency. Due to the high cooling air velocity at the blade root, this flow turn is particularly severe, resulting in greater energy losses. As cooling air continuously exits the slit channels, the cooling air flow rate at the upper slit gradually decreases. Furthermore, squeezed by the turning airflow below, the cooling air has already made a partial turn before entering the upper slit channels. Upon reaching the top end of the blade internal channel, the airflow is constrained by the blind end and naturally deflected toward the trailing edge. Therefore, for slits near the blade tip, the turning angle of the cooling air upon entering the channel is significantly lower than for slits at the blade root. According to this flow characteristic, the present invention adopts a cooling structure with variable curvature on both sides of the basin back to optimize the inlet and outlet angles of the slit channels at different radial heights. Figure 2(a) and 2(b) As shown, the slit channel located at the bottom is designed as an inclined curved channel structure, so that the turning angle of the cooling air in the slit changes from an approximately right angle to an acute angle, the flow is smoother, the generation of vortices is weakened, and the internal flow resistance is reduced. The slit channel located at the top adopts a curved slit or horizontal slit structure with a smaller inclination angle, so that the cooling air always maintains a smaller flow turning angle when entering the slit channel, and the flow loss caused by the turning of the cooling air is also reduced. As a result, the slit cooling structure of the present invention has good flow resistance reduction performance at all radial heights. In addition, the slit cooling structure of the present invention also presents the characteristics of a curved channel in the blade top-down dimension, and the cooling air in the inner cavity cooling air channel is smoothly guided to both sides of the trailing edge basin back, further reducing the flow loss inside the slit channel. In summary, the basin back double-sided variable curvature slit cooling structure of the present invention can reduce the overall flow loss inside the cooling air by about 15%.

[0029] 6. Forming a periodic complementary support structure and a zigzag diagonal bracing structure, greatly improving the load resistance of the trailing edge structure

[0030] In traditional horizontally vented slit structures, the alternating arrangement of slit channels and ribs causes the trailing edge cross-sectional area to exhibit significant periodic variations along the radial direction. The trailing edge section at the ribs has a high material solidity ratio and is less susceptible to damage. However, the trailing edge section at the slit opening is weak due to a high degree of hollowing and a lack of effective support and reinforcement. In actual operation, the root of a turbine rotor blade experiences the greatest centrifugal load, while the middle of the blade experiences significant stress due to high-order bending and torsional vibrations. The top of the blade experiences lighter loads and is less susceptible to damage. In view of the load distribution characteristics of turbine blades, the trailing edge cooling structure of the present invention adopts an optimized design with variable curvature, and adopts an inclined curved slit structure at the root and middle of the blade where the stress is greater. The inclined partition ribs formed between the slit channels can achieve a support structure connecting the two sides of the blade's back at any cross-sectional position, thereby forming a periodic complementary support in the radial direction, greatly improving the load resistance of the trailing edge structure. At the tip of the blade where the load is lighter, a curved slit or horizontal slit structure with a smaller inclination angle is adopted to optimize the distribution of materials at different radial heights. In addition, the variable curvature slits on both sides of the back of the back of the present invention adopt triangular cross-section channels to form a zigzag diagonal bracing structure on the trailing edge section perpendicular to the chord direction, as shown in Figure 2(f), which can effectively increase the rigidity of the trailing edge structure and improve its ability to resist bending, torsion and centrifugal loads. The variable curvature slit cooling structure on both sides of the back of the back of the present invention can increase the load resistance of the trailing edge structure of the blade by about 20%. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] FIG1( a ) is a front view of a conventional turbine blade with horizontal exhaust slot cooling on the trailing edge.

[0032] Figure 1(b) is a cross-sectional view of an existing turbine blade with horizontal exhaust slot cooling on the trailing edge.

[0033] Figure 2(a) is a front view of a turbine blade basin with a trailing edge cooled by variable-camber slits on both sides of the basin back.

[0034] Figure 2(b) is a front view of the back side of a turbine blade with a trailing edge that uses variable-camber slits on both sides of the basin to cool the blade.

[0035] Figure 2(c) is a cross-sectional view of a turbine blade BB with a trailing edge cooled by variable-camber slits on both sides of the basin back.

[0036] Figure 2(d) is a cross-sectional view of a turbine blade CC with a trailing edge cooled by variable-camber slits on both sides of the basin back.

[0037] Figure 2(e) is a partial enlarged view of the trailing edge of a turbine blade whose trailing edge is cooled by variable-camber slits on both sides of the basin back.

[0038] Figure 2(f) is a cross-sectional view of a turbine blade DD with a trailing edge cooled by variable-camber slits on both sides of the basin back.

[0039] In the figure: 1. Hollow turbine blade; 2. Inner cavity cooling air channel; 3. Horizontal slit channel on the trailing edge; 4. Variable curvature slit channel on the basin side of the trailing edge; 5. Variable curvature slit channel on the back side of the trailing edge; 6. Centerline of the slit channel; 7. Width w of the slit channel; 8. Inlet angle ∠α of the slit channel; 9. Outlet angle ∠β of the slit channel; 10. Height h of the slit channel; 11. Vertex angle ∠A of the triangular section of the slit channel; 12. Wall thickness t between the slit channels. DETAILED DESCRIPTION

[0040] In order to make the contents of the present invention more clearly understood, the present invention is further described in detail below based on specific embodiments in conjunction with the accompanying drawings.

[0041] Example 1:

[0042] Referring to Figures 2(a) to 2(f), a turbine blade with a trailing edge cooled by a slit with variable curvature on both sides of the basin and back comprises a hollow turbine blade (1), an inner cavity cooling air passage (2), a slit passage with variable curvature on the basin side of the trailing edge (4), and a slit passage with variable curvature on the back side of the trailing edge (5);

[0043] The hollow turbine blade (1) is provided with an inner cavity cooling air channel (2) for low-temperature cooling gas to flow inside the blade to cool the blade. The trailing edge of the hollow turbine blade (1) is provided with a trailing edge basin-side variable-curvature slit channel (4) and a trailing edge back-side variable-curvature slit channel (5) alternately arranged along the radial direction, so that the cooling air in the inner cavity cooling air channel (2) is alternately discharged to the basin back sides of the blade through the slit channels, and forms an air film on the outer wall to evenly cool the trailing edge area of the blade.

[0044] The structural shape of the trailing edge basin side variable curvature slit channel (4) and the trailing edge back side variable curvature slit channel (5) along the flow direction is controlled by the slit channel centerline (6). In the blade top view dimension, the projection of the slit channel centerline (6) is a spline curve or an arc-shaped curve. When it bends toward the trailing edge basin side, a smooth trailing edge basin side variable curvature slit channel (4) is formed; when it bends toward the trailing edge back side, a smooth trailing edge back side variable curvature slit channel (5) is formed. In the blade main view dimension, the projection of the slit channel centerline (6) is an arc-shaped curve, an inclined straight line or a horizontal straight line. Accordingly, the formed trailing edge basin side variable curvature slit channel (4) and the trailing edge back side variable curvature slit channel (5) are inclined curved channels, inclined straight channels or horizontal straight channels in the blade main view direction.

[0045] The present invention adopts a variable curvature design for the center line (6) of the slit channel at different radial positions, and the slit channel inlet angle ∠α (8) and the slit channel outlet angle ∠β (9) change regularly with the channel number n, and the functional relationship is shown in formulas (1) to (2). Typically, α1 can be 35°, β1 can be 25°, α i It can be 20°, β i It can be 10°, α max Can be 45°, β max It can be 35°.

[0046] The cross-sectional shapes of the variable-curvature slit channel (4) on the trailing edge basin side and the variable-curvature slit channel (5) on the trailing edge dorsal side are isosceles triangles. The cross-sectional triangles of the two are symmetrically staggered and present a periodic close-packed characteristic along the radial direction, as shown in Figure 2(f). The cross-sectional characteristics of the triangular channel can be described by the slit channel width w (7), the slit channel height h (10), and the apex angle ∠A (11) of the slit channel triangle cross-sectional area. The smaller the slit channel width, the higher the height, and the larger the apex angle ∠A, the flatter the slit channel. Ignoring the influence of the slit channel fillet, the relationship between the three can be expressed as formula (3).

[0047] An inclined inner wall is formed between the adjacent trailing edge basin-side variable curvature slit channels (4) and the trailing edge back-side variable curvature slit channels (5), which can play a supporting and strengthening role for the trailing edge. Multiple inclined inner walls are sequentially connected in the radial direction to form a "Z"-shaped support structure on the trailing edge section perpendicular to the chord direction, which can improve the ability of the blade trailing edge to resist bending, torsion and centrifugal loads. The smaller the radial consistency of the slit, the greater the wall thickness t (12) between the slit channels, the thicker the "Z"-shaped support formed, and the more obvious the strengthening effect on the trailing edge structure, but the cooling effect on the trailing edge will also deteriorate accordingly. Typically, the vertex angle ∠A (11) of the triangular section of the slit channel can be 150°, the width-to-height ratio w / h of the slit channel can be 0.13, and the ratio t / h of the wall thickness between the slit channels to the height of the slit channel can be 0.1.

[0048] Example 2:

[0049] Referring to Figures 2(a) to 2(f), a turbine blade with a trailing edge cooled by a slit with variable curvature on both sides of the basin and back comprises a hollow turbine blade (1), an inner cavity cooling air passage (2), a slit passage with variable curvature on the basin side of the trailing edge (4), and a slit passage with variable curvature on the back side of the trailing edge (5);

[0050] The hollow turbine blade (1) is provided with an inner cavity cooling air channel (2) for low-temperature cooling gas to flow inside the blade to cool the blade. The trailing edge of the hollow turbine blade (1) is provided with a trailing edge basin-side variable-curvature slit channel (4) and a trailing edge back-side variable-curvature slit channel (5) alternately arranged along the radial direction, so that the cooling air in the inner cavity cooling air channel (2) is alternately discharged to the basin back sides of the blade through the slit channels, and forms an air film on the outer wall to evenly cool the trailing edge area of the blade.

[0051] The structural shape of the trailing edge basin side variable curvature slit channel (4) and the trailing edge back side variable curvature slit channel (5) along the flow direction is controlled by the slit channel centerline (6). In the blade top view dimension, the projection of the slit channel centerline (6) is a spline curve or an arc-shaped curve. When it bends toward the trailing edge basin side, a smooth trailing edge basin side variable curvature slit channel (4) is formed; when it bends toward the trailing edge back side, a smooth trailing edge back side variable curvature slit channel (5) is formed. In the blade main view dimension, the projection of the slit channel centerline (6) is an arc-shaped curve, an inclined straight line or a horizontal straight line. Accordingly, the formed trailing edge basin side variable curvature slit channel (4) and the trailing edge back side variable curvature slit channel (5) are inclined curved channels, inclined straight channels or horizontal straight channels in the blade main view direction.

[0052] The present invention adopts a variable curvature design for the center line (6) of the slit channel at different radial positions, and the slit channel inlet angle ∠α (8) and the slit channel outlet angle ∠β (9) change regularly with the channel number n, and the functional relationship is shown in formulas (1) to (2). Typically, α1 can be 10°, β1 can be 0°, α i Can be 0°, β i Can be 0°, α max Can be 25°, β max It can be 15°.

[0053] The cross-sectional shapes of the variable-curvature slit channel (4) on the trailing edge basin side and the variable-curvature slit channel (5) on the trailing edge dorsal side are isosceles triangles. The cross-sectional triangles of the two are symmetrically staggered and present a periodic close-packed characteristic along the radial direction, as shown in Figure 2(f). The cross-sectional characteristics of the triangular channel can be described by the slit channel width w (7), the slit channel height h (10), and the apex angle ∠A (11) of the slit channel triangle cross-sectional area. The smaller the slit channel width, the higher the height, and the larger the apex angle ∠A, the flatter the slit channel. Ignoring the influence of the slit channel fillet, the relationship between the three can be expressed as formula (3).

[0054] An inclined inner wall is formed between the adjacent trailing edge basin-side variable curvature slit channels (4) and the trailing edge back-side variable curvature slit channels (5), which can play a supporting and strengthening role for the trailing edge. Multiple inclined inner walls are sequentially connected in the radial direction to form a "Z"-shaped support structure on the trailing edge section perpendicular to the chord direction, which can improve the ability of the blade trailing edge to resist bending, torsion and centrifugal loads. The smaller the radial consistency of the slit, the greater the wall thickness t (12) between the slit channels, the thicker the "Z"-shaped support formed, and the more obvious the strengthening effect on the trailing edge structure, but the cooling effect on the trailing edge will also deteriorate accordingly. Typically, the vertex angle ∠A (11) of the triangular section of the slit channel can be 110°, the width-to-height ratio w / h of the slit channel can be 0.35, and the ratio t / h of the wall thickness between the slit channels to the height of the slit channels can be 0.25.

Claims

1. A turbine blade with a trailing edge cooled by a double-sided variable-camber slit on the back of the basin, characterized in that: It comprises a hollow turbine blade (1), an inner cavity cooling air channel (2), a trailing edge basin side variable curvature split channel (4), and a trailing edge back side variable curvature split channel (5); An inner cavity cooling air channel (2) is provided inside the hollow turbine blade (1) for allowing low-temperature cooling gas to flow inside the blade to cool the blade; The trailing edge of the hollow turbine blade (1) is provided with a trailing edge basin side variable camber slit channel (4) and a trailing edge back side variable camber slit channel (5) alternately along the radial direction, the total number of the trailing edge basin side variable camber slit channel (4) and the trailing edge back side variable camber slit channel (5) is i, and the number n thereof changes from 1 to i along the direction from the blade root to the blade tip; The structural shapes of the trailing edge basin side variable curvature slit channel (4) and the trailing edge back side variable curvature slit channel (5) along the flow direction are controlled by the slit channel center line (6); in the blade top view dimension, the projection of the slit channel center line (6) is a spline curve or an arc curve, and in the blade main view dimension, the projection of the slit channel center line (6) is an arc curve, an inclined straight line or a horizontal straight line. Accordingly, the formed trailing edge basin side variable curvature slit channel (4) and the trailing edge back side variable curvature slit channel (5) are inclined curve channels, inclined straight channels or horizontal straight channels in the blade main view direction, and the angles between the tangent direction of the slit channel center line (6) at the cold air inlet end and the cold air outlet end and the horizontal plane are the slit channel inlet angle ∠α (8) and the slit channel outlet angle ∠β (9), respectively, and ∠α≥∠β; The center line (6) of the slit channel at different radial positions adopts a variable curvature design, and the slit channel inlet angle ∠α (8) and the slit channel outlet angle ∠β (9) change regularly with the channel number n. The functional relationship is shown in formulas (1) to (2): Where i is the total number of slit channels, α1 and β1 are the inlet angle and outlet angle of the slit channel closest to the blade root when n=1, respectively. i and β i When n=i, they are the inlet angle and outlet angle of the slit channel closest to the blade tip, α max and β max are the maximum values of the inlet angle and outlet angle of the splitting channel, respectively, and α1>β1, α i ≥β i , α max >β max .

2. A turbine blade with trailing edge cooling using double-sided variable camber slits on the back of the basin as claimed in claim 1, characterized in that: The cross-sectional shape of the trailing edge basin side variable curvature split channel (4) and the trailing edge dorsal side variable curvature split channel (5) is an isosceles triangle. The cross-sectional triangles of the two are symmetrically staggered and present a periodic close arrangement along the radial direction. The cross-sectional characteristics of the triangular channel can be described by the split channel width w (7), the split channel height h (10) and the split channel triangle cross-sectional vertex angle ∠A (11). The smaller the width of the split channel, the higher the height and the larger the vertex angle ∠A, the flatter the split channel. Ignoring the influence of the rounded corners of the split channel, the relationship between the three can be expressed as formula (3): h=2w·tan(A / 2) (3).

3. A turbine blade with trailing edge cooling using double-sided variable camber slits on the back of the basin as claimed in claim 2, characterized in that: The apex angle ∠A(11) of the triangular cross section of the slit channel is 110-150 degrees, the width-to-height ratio w / h of the slit channel is 0.13-0.35, and the ratio t / h of the wall thickness between the slit channels and the height of the slit channels is 0.1-0.

25.

4. A turbine blade with trailing edge cooling using variable camber slits on both sides of the basin back as claimed in claim 1, 2 or 3, characterized in that: The α1 is 10-35°, β1 is 0-25°, α i 0~20°, β i 0~10°, α max 25~45°, β max It is 15 to 35 degrees.

5. A turbine blade with trailing edge cooling using double-sided variable camber slits on the back of the basin as claimed in claim 1, 2 or 3, characterized in that: When ∠α and ∠β are equal to 0°, the projection of the center line (6) of the slit channel in the main viewing dimension is a horizontal straight line, and the slit is horizontal.

6. A turbine blade with trailing edge cooling using double-sided variable camber slits on the back of the basin as claimed in claim 4, characterized in that: When ∠α and ∠β are equal to 0°, the projection of the center line (6) of the slit channel in the main viewing dimension is a horizontal straight line, and the slit is horizontal.

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