Turbine blade tail edge half-crack cooling structure, turbine blade, turbine and aero-engine

Abstract

The utility model relates to a turbine blade tail edge half crack cooling structure, a turbine blade, a turbine and an aero-engine, belongs to the technical field of aero-engines, and solves the problem that a tail edge area is difficult to cool in the prior art. The blade comprises a blade tail edge pressure surface and a half-crack structure, the half-crack structure is a groove formed in the pressure face of the blade tail edge and used for enabling internal cooling gas to flow out so as to reduce the temperature of the blade tail edge. The half-split seam structure comprises a trailing edge half-split seam wall surface and a convex block; the convex block is arranged on the wall surface of the trailing edge half crack; the protruding blocks are of a water-drop-shaped structure. The bump is provided with a side surface, a bottom surface and a top surface; the side surface is a plane; and the top surface and the bottom surface are curved surfaces. The cooling effect of the trailing edge area can be improved.

Description

Technical Field

[0001] This utility model relates to the field of aero-engine technology, and in particular to a turbine blade trailing edge semi-slit cooling structure, a turbine blade, a turbine, and an aero-engine. Background Technology

[0002] Currently, the turbine inlet temperature of advanced aero-engines reaches as high as 2200K, far exceeding the temperature resistance limit of turbine blade materials. Therefore, efficient cooling technologies are essential to ensure their normal operation. Commonly used turbine blade cooling methods include external cooling (film cooling), internal cooling (jet impingement, baffles / pillars to enhance heat transfer), and composite cooling (double-walled cooling).

[0003] Because the outer gas flow often becomes turbulent when it reaches the trailing edge of the turbine blade, the heat transferred from the gas flow to the trailing edge is enhanced. The externally cooled gas film is usually located in the leading edge region and has a smaller impact on the trailing edge. The internally cooled gas continuously absorbs heat during its flow, resulting in a higher temperature when it reaches the trailing edge region, leading to a relatively poor cooling effect. The combination of these factors makes cooling in the trailing edge region quite difficult. Utility Model Content

[0004] Based on the above analysis, the present invention aims to provide a turbine blade trailing edge semi-slit cooling structure, turbine blade, turbine, and aero-engine to solve the problem of difficult cooling in the trailing edge region.

[0005] The objective of this utility model is mainly achieved through the following technical solutions:

[0006] The first aspect of this utility model is to provide a turbine blade trailing edge semi-slit cooling structure, including a blade trailing edge pressure surface and a semi-slit structure.

[0007] The semi-slit structure is a groove provided on the pressure surface of the blade trailing edge, used to allow internal cooling gas to flow out and reduce the temperature of the blade trailing edge; the semi-slit structure includes a trailing edge semi-slit wall and a protrusion; the protrusion is provided on the trailing edge semi-slit wall.

[0008] The protrusion has a teardrop-shaped structure; the protrusion has a side surface, a bottom surface, and a top surface; the side surface is a plane; the top surface and the bottom surface are curved surfaces.

[0009] Furthermore, one end of the protrusion is semi-circular, and the other end of the protrusion is pointed;

[0010] The groove forms an opening on the trailing edge pressure surface of the blade, with the semi-circular end facing the opening on the trailing edge pressure surface of the blade; the tip faces the airflow rear region of the semi-slit structure.

[0011] Furthermore, the tip conforms to the wall surface of the trailing edge semi-split.

[0012] Furthermore, the protrusions are arranged in an array on the trailing edge semi-split wall.

[0013] Furthermore, the bumps in adjacent rows are arranged in an alternating pattern.

[0014] Furthermore, if the maximum height of the protrusion is set to h, and the wall thickness of the trailing edge is set to δ, then h:δ=0.1~0.5; if the spacing of the protrusion in the airflow direction is set to the flow spacing x, and the diameter of the semi-circular end of the protrusion is set to D, then x:D=1.5~5;

[0015] Let the direction perpendicular to the longitudinal axis of symmetry be the spanning direction, and the distance between adjacent longitudinal axes of symmetry of the protrusions in the spanning direction be the spanning distance y. Then the ratio of y to the diameter D of the protrusion head is y: D = 1.5~5.

[0016] Furthermore, the groove has multiple recesses.

[0017] A second aspect of this utility model provides a turbine blade, including the aforementioned turbine blade trailing edge semi-slit cooling structure.

[0018] A third aspect of this invention provides a turbine, including the aforementioned turbine blades.

[0019] A fourth aspect of this invention provides an aircraft engine, including the aforementioned turbine.

[0020] Compared with the prior art, the present invention can achieve at least one of the following beneficial effects:

[0021] (1) Compared with the prior art, the present invention sets a teardrop-shaped protrusion in the semi-slit structure. The top and bottom surfaces of the teardrop-shaped protrusion are curved, and the side surfaces are flat. One end of the protrusion is a semi-circular end, and the other end is a pointed end. When the cold flow passes over the protrusion, it flows along the edges of different heights on the top surface of the teardrop-shaped protrusion, forming enhanced turbulence along the wall, increasing the heat transfer area, and enhancing the convective heat transfer intensity of the semi-slit film cooling.

[0022] (2) In this invention, along the airflow direction, the height of the protrusion gradually decreases from the semi-circular end to the tip, forming different height levels. The semi-circular end of the protrusion is tall, which is beneficial for turbulence and cold air distribution; the tip is low, which can enhance heat exchange and stabilize the air film. This invention makes full use of space by utilizing the distribution of different heights, thereby improving the cooling effect.

[0023] (3) The setting of the tip of the bump attached to the wall reduces the tip trail area and reduces the flow resistance; at the same time, the tip attached to the wall makes it easier for the airflow in the rear area to form an air film, which can better guide the airflow to flow in the rear area attached to the wall, which is conducive to the spread of the cooling air film in the downstream area of ​​the half-slit, isolates the combustion gas, realizes the composite cooling of internal enhanced heat exchange and tail edge slit air film cooling, and improves the air film cooling effect on the tail edge pressure surface.

[0024] (4) In order to have as many turbulence structures as possible on the wall surface of the entire semi-splitting structure, this utility model sets up a protrusion array on the semi-splitting wall surface; at the same time, in order to prevent the existence of areas with large differences in flow resistance, the teardrop-shaped protrusions in adjacent rows are arranged alternately.

[0025] (5) Due to the low height of the bump structure, the cooling effect is not obvious; if the height exceeds the thickness of the trailing edge, it will affect the airflow and hinder the smooth flow of cold air. The ratio of the maximum height h of the teardrop-shaped bump to the thickness δ of the trailing edge wall is set to h:δ=0.1~0.5 to increase the stability of the air film. Considering that if the spacing of the bumps is too small, the airflow will be obstructed, and if the spacing is too large, the heat exchange effect cannot be effectively enhanced. The ratio of the flow spacing x of the bumps to the diameter D of the head of the teardrop-shaped bump is set to x:D=1.5~5; the ratio of the spanwise spacing y to the diameter D of the head of the bump is y:D=1.5~5.

[0026] In this invention, the above-described technical solutions can be combined with each other to achieve more preferred combinations. Other features and advantages of this invention will be set forth in the following description, and some advantages will become apparent from the description or be learned by practicing this invention. The objectives and other advantages of this invention can be realized and obtained from the details specifically pointed out in the text and accompanying drawings. Attached Figure Description

[0027] The accompanying drawings are for illustrative purposes only and are not intended to limit the scope of the invention. Throughout the drawings, the same reference numerals denote the same parts.

[0028] Figure 1 This is a schematic diagram of the turbine blade trailing edge turbulence semi-slit cooling structure with teardrop-shaped protrusions, as shown in the embodiment.

[0029] Figure 2 This is a schematic diagram of the teardrop-shaped protrusion.

[0030] Figure 3 A schematic diagram of the structure for setting up teardrop-shaped protrusions within a single half-slit structure;

[0031] Figure 4 A cross-sectional schematic diagram of the semi-slit cooling structure for the trailing edge turbulence of the blade.

[0032] Figure 5 A cold airflow curve diagram of the simulation results;

[0033] Figure 6 This is a diagram showing the heat transfer coefficient distribution of the teardrop-shaped bump.

[0034] Figure label:

[0035] 1-Blade trailing edge pressure surface, 2-Blade trailing edge suction surface, 3-Semi-slit structure, 301-Spacer rib, 302-Trailing edge semi-slit wall, 303-Protrusion, 3031-Side side, 3032-Bottom surface, 3033-Top surface, 4-Cold flow inlet, 5-Cold flow outlet. Detailed Implementation

[0036] The preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings, which constitute a part of the present invention and are used together with the embodiments of the present invention to illustrate the principles of the present invention, but are not intended to limit the scope of the present invention.

[0037] A specific embodiment of this utility model is as follows: Figure 1 As shown, a turbine blade trailing edge semi-slit cooling structure is disclosed, which is applied to aero-engine turbine blades, including a blade trailing edge pressure surface 1 and a semi-slit structure 3.

[0038] The blade trailing edge pressure surface 1 is connected to the internal cooling channel of the blade. In order to enable the cooling airflow to flow out effectively and cover the trailing edge surface, a groove is provided on the blade trailing edge pressure surface 1 to form a semi-slit structure 3.

[0039] The semi-split structure 3 includes a spacer rib 301, a trailing semi-split wall 302, and a protrusion 303.

[0040] The spacer rib 301 is used to separate adjacent half-split structures 3. The trailing edge half-split wall 302 is located on the bottom surface of the half-split structure 3.

[0041] The protrusion 303 is disposed on the upper part of the semi-slit wall 302 at the trailing edge. When the cooling airflow flows out through the semi-slit, the protrusion 303 will cause the airflow to generate vortices and turbulence, enhance the mixing between the cooling air film and the high-temperature combustion gas, and make the air film more stable.

[0042] It also includes a blade trailing edge suction surface 2, the shape of which is the same as the overall shape of the blade trailing edge. In this embodiment, the blade trailing edge suction surface 2 is an inclined surface, and the blade trailing edge pressure surface 1 is a plane. When the cooling airflow enters the semi-slit structure 3, with the cooperation of the blade trailing edge suction surface 2, the airflow can better adhere to the trailing edge surface.

[0043] The blade trailing edge has an internal cooling channel. A cold flow inlet 4 is located on one side of the blade trailing edge pressure surface 1. A cold flow outlet 5 is located at the opening of the blade trailing edge pressure surface 1 in the slot. The cold flow inlet 4 and the cold flow outlet 5 are connected by a semi-slit formed by the internal cooling channel penetrating the blade trailing edge.

[0044] Cooling airflow enters through the cold flow inlet 4, exits through the cold flow outlet 5 via the slit, and enters the semi-slit structure 3. It mixes with the high-temperature mainstream airflow from the blade trailing edge pressure surface 1, and is then sprayed onto the surface along the trailing edge direction, forming a cooling gas film on the trailing edge slit wall. This cooling gas film serves two purposes: firstly, it isolates the trailing edge region from the heating effect of the combustion gases from the blade trailing edge pressure surface 1, thus forming film cooling; secondly, it absorbs and cools the heat introduced by the combustion gases from the blade trailing edge suction surface 2 through the trailing edge wall, thus forming internal cooling.

[0045] For example, such as Figure 2 As shown, the protrusion 303 in this embodiment is a teardrop-shaped protrusion 303. The protrusion 303 has a side surface 3031, a bottom surface 3032, and a top surface 3033. The side surface 3031 of the protrusion 303 is flat, while the top surface 3033 and the bottom surface 3032 are curved surfaces. One end of the protrusion 303 is semi-circular, and the other end is pointed. The groove forms an opening on the blade trailing edge pressure surface 1, with the semi-circular end facing the opening of the blade trailing edge pressure surface 1; the pointed end is attached to the wall and faces the end of the semi-slit structure 3.

[0046] The protrusion 303 has a symmetrical structure with a longitudinal axis of symmetry. Preferably, in order to reduce the interference between the cooling gas film and the gas flow and to better maintain the stability of the gas film, the direction of the longitudinal axis of symmetry of the protrusion 303 is set to be parallel to the flow direction of the airflow.

[0047] The protrusion 303 is arranged in a teardrop shape, with its semi-circular end facing the opening of the pressure surface 1 at the blade trailing edge. The height of the protrusion 303 gradually decreases from the semi-circular end to the tip, forming a smooth curved surface. The large height of the semi-circular end of the protrusion 303 is beneficial for turbulence and cold air distribution; the low height of the tip against the wall enhances heat exchange and stabilizes the air film. The different heights of the protrusion 303 make full use of space and improve the cooling effect.

[0048] Compared to existing technologies, this embodiment features teardrop-shaped protrusions 303 within the semi-slit structure 3. The top surface 3033 and bottom surface 3032 of the teardrop-shaped protrusions 303 are curved, while the side surface 3031 is flat. One end of the protrusion 303 is semi-circular, and the other end is pointed. When cold air passes over the protrusion 303, it flows along edges of varying heights on the top surface 3033 of the teardrop-shaped protrusion 303, forming enhanced turbulence along the wall, increasing the heat exchange area, and strengthening the convective heat transfer intensity of the semi-slit film cooling. In this embodiment, the height of the protrusion 303 gradually decreases from the semi-circular end to the pointed end. The larger height of the semi-circular end of the protrusion 303 facilitates turbulence and cold air distribution, while the lower height of the pointed end enhances heat exchange and stabilizes the film. The teardrop-shaped protrusions 303 in this embodiment can fully utilize space by employing a distribution of different heights, thereby improving the cooling effect.

[0049] In this embodiment, the tip of the teardrop-shaped protrusion 303 is attached to the wall to reduce the tail area and lower the flow resistance. At the same time, the tip attached to the wall can better guide the airflow to flow along the wall in the rear area, making it easier for the airflow in the rear area to form an air film. This is beneficial for the longitudinal coverage of the cooling air film in the downstream area of ​​the half-slit, isolating the combustion gas and realizing a composite cooling that combines internal enhanced heat transfer with tail-edge slit air film cooling, thereby improving the air film cooling effect on the tail-edge pressure surface.

[0050] To ensure that the walls of the entire semi-slit structure 3 contain as many turbulence structures as possible, such as... Figure 3 As shown, the protrusions 303 are arranged in an array on the half-slit wall. Preferably, to prevent areas with large differences in flow resistance, the teardrop-shaped protrusions 303 in adjacent rows are arranged alternately.

[0051] Furthermore, because the height of bump 303 is too low, its cooling effect is not significant; if its height exceeds the thickness of the trailing edge, it will affect airflow and hinder the smooth flow of cold air, such as... Figure 4 As shown, in this embodiment, the ratio of the maximum height h of the teardrop-shaped protrusion 303 to the tail edge wall thickness δ is set to h:δ=0.1~0.5, so as to increase the stability of the air film.

[0052] Considering that too small a spacing between the protrusions 303 would lead to poor airflow, while too large a spacing would not effectively enhance the heat exchange effect, preferably, the ratio of the flow spacing (from the airflow inlet to the outlet) x of the protrusions 303 to the diameter D of the head of the teardrop-shaped protrusion 303 is set to x:D = 1.5~5. The direction perpendicular to the longitudinal axis of symmetry is defined as the spanwise direction, and the spacing between adjacent protrusions 303 along their longitudinal axes of symmetry in the spanwise direction is defined as the spanwise spacing y. Therefore, the ratio of y to the diameter D of the head of the protrusion 303 is y:D = 1.5~5. The number of teardrop-shaped protrusions 303 in the transverse and longitudinal directions is determined based on the flow length L of the semi-slit wall, the flow spacing x of the teardrop-shaped protrusions 303, and the spanwise spacing y.

[0053] like Figure 5 and Figure 6 As shown, the turbulent semi-slit cooling structure with teardrop-shaped protrusions 303 and the semi-slit wall of the conventional semi-slit structure 3 were simulated under the same conditions. In the turbine blade trailing edge turbulent semi-slit cooling structure with teardrop-shaped protrusions 303, five teardrop-shaped protrusions 303 were arranged on the trailing edge slit wall. The teardrop-shaped protrusions 303 were staggered, with a flow direction spacing x of 0.6 mm and a spanwise spacing y of 0.6 mm. Both were simulated under the same conditions. The upper part of the semi-slit structure 3 was a lip plate with a thickness t of 0.4 mm, a trailing edge wall thickness δ of 1.0 mm, a cold flow outlet height s of 0.5 mm, and a blowing ratio M of 1.0. The simulation results showed that the heat transfer coefficient of the semi-slit wall of the conventional semi-slit structure was 1545.37 W / m². 2 In this embodiment, the heat transfer coefficient of the turbulent semi-slit cooling structure with teardrop-shaped protrusions 303 is 3067.47 W / m². 2 ·k. The heat transfer coefficient of this embodiment is significantly higher than that of the semi-slit wall of the conventional semi-slit structure 3. Therefore, the turbine blade trailing edge turbulence semi-slit cooling structure with teardrop-shaped protrusions 303 can effectively improve the heat transfer effect and reduce the wall temperature of the blade trailing edge suction surface 2.

[0054] This utility model embodiment also provides a turbine blade, including the turbine blade trailing edge semi-slit cooling structure in the above embodiments.

[0055] This utility model embodiment also provides a turbine, including the turbine blades in the above embodiments.

[0056] This utility model embodiment also provides an aircraft engine, including the turbine in the above embodiments.

[0057] Compared with the prior art, the advantages of the turbine blades, turbines and aero engines of this utility model embodiment are the same as those of the turbine blade trailing edge semi-slit cooling structure described above, and will not be repeated here.

[0058] The above description is only a preferred embodiment of the present utility model, but the protection scope of the present utility model is not limited thereto. Any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present utility model should be included within the protection scope of the present utility model.

Claims

1. A semi-slit cooling structure for the trailing edge of a turbine blade, characterized in that, It includes the blade trailing edge pressure surface (1) and the semi-slit structure (3); The semi-slit structure (3) is a groove provided on the blade trailing edge pressure surface (1) to allow internal cooling gas to flow out and reduce the temperature of the blade trailing edge; the semi-slit structure (3) includes a trailing edge semi-slit wall surface (302) and a protrusion (303); The protrusion (303) is disposed on the tail edge semi-split wall (302); the protrusion (303) has a teardrop-shaped structure; the protrusion (303) has a side surface (3031), a bottom surface (3032) and a top surface (3033); the side surface (3031) is a plane; the top surface (3033) and the bottom surface (3032) are curved surfaces.

2. The turbine blade trailing edge semi-slit cooling structure according to claim 1, characterized in that, One end of the protrusion (303) is semi-circular, and the other end of the protrusion (303) is pointed; The groove forms an opening on the trailing edge pressure surface of the blade, the semi-circular end faces the opening of the trailing edge pressure surface (1) of the blade, and the tip faces the airflow rear region of the semi-slit structure (3).

3. The turbine blade trailing edge semi-slit cooling structure according to claim 2, characterized in that, The tip is attached to the semi-split wall (302) of the tail edge.

4. The turbine blade trailing edge semi-slit cooling structure according to claim 1, characterized in that, The protrusions (303) are arranged in an array on the trailing edge semi-split wall (302).

5. The turbine blade trailing edge semi-slit cooling structure according to claim 4, characterized in that, The bumps (303) in adjacent rows are staggered.

6. The turbine blade trailing edge semi-slit cooling structure according to claim 5, characterized in that, If the maximum height of the bump (303) is h and the wall thickness of the trailing edge is δ, then h: δ = 0.1~0.5; The spacing between the protrusions (303) in the airflow direction is set as the flow spacing x, and the diameter of the semi-circular end of the protrusion (303) is D, then x:D = 1.5~5; The direction perpendicular to the longitudinal axis of symmetry is set as the spanning direction, and the distance between the longitudinal axes of symmetry of adjacent protrusions (303) in the spanning direction is set as the spanning distance y. Then, the ratio of y to the diameter D of the semi-circular end of the protrusion (303) is y: D = 1.5~5.

7. The turbine blade trailing edge semi-slit cooling structure according to claim 1, characterized in that, The groove has multiple grooves.

8. A turbine blade, characterized in that, Includes the turbine blade trailing edge semi-slit cooling structure as described in any one of claims 1-7.

9. A turbine, characterized in that, Includes the turbine blade as described in claim 8.

10. An aircraft engine, characterized in that, Includes the turbine as described in claim 9.

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