CN117211889A - Fish scale-shaped turbine blade cooling structure and turbine blade - Google Patents

Abstract

The application provides a fish scale-shaped turbine blade cooling structure and a turbine blade, wherein the cooling structure comprises: a cool air supply cavity and a fish scale type turbine blade cooling channel; the fish scale-shaped turbine blade cooling channel is provided with a plurality of straight inlet sections at the initial end and a plurality of straight outlet sections at the tail end, and the straight inlet sections are communicated with the cold air supply cavity; the fish scale-shaped turbine blade cooling channel is formed by staggered arrangement of a second fish scale-shaped vortex column assembly and a first fish scale-shaped vortex column assembly, the second fish scale-shaped vortex column assembly comprises a plurality of second fish scale-shaped vortex columns arranged according to an array, the first fish scale-shaped vortex column assembly comprises a plurality of first fish scale-shaped vortex columns arranged according to the array, the edge gaps of adjacent vortex columns are mutually communicated, the upstream of the second fish scale-shaped vortex columns is communicated with a straight inlet section, and the downstream of the first fish scale-shaped vortex columns is communicated with a straight outlet section to form a netty cooling channel. The application strengthens the convection heat exchange effect inside the turbine blade and improves the cooling efficiency and the temperature bearing capacity of the blade.

Description

Fish scale-shaped turbine blade cooling structure and turbine blade

Technical Field

The application relates to the technical field of aeroengines, in particular to a fish scale-shaped turbine blade cooling structure and a turbine blade.

Background

Increasing turbine inlet temperature is an effective way to increase aeroengine thrust and efficiency, but increasing turbine inlet temperature can subject turbine blades to greater thermal loads, and excessive temperatures and thermal stresses can cause the turbine blades to fail. The turbine inlet gas temperature of modern high performance aeroengines has far exceeded the temperature tolerance limit of the materials used, and complex cooling techniques must be employed to ensure proper operation of the turbine under high temperature conditions. The mid-chord and trailing edge regions of a turbine blade are typically high temperature regions of the blade, which are relatively vulnerable to hot corrosion. In particular, the cooling aspects of the chord zone in high pressure turbine blades are very critical. For the middle chord zone of the high-pressure turbine blade, even the transonic blade is also supersonic in the local area of the tail edge, and most of the rest is in a subsonic state, so that most of the positions of the middle chord zone can be provided with air film holes. In general, the middle chord zone adopts a composite cooling structure form such as 'impact + convection + air film' or 'convection + air film', and the gas pressure in the middle chord zone is higher due to higher pressure loss of an internal cooling structure, so that the problem that local air film holes are subjected to gas backflow due to insufficient pressure backflow margin can generally occur, and the blade is overheated and even ablated. In addition, the design difficulty of the turbine blade trailing edge cooling structure is also very outstanding, and the main reason is that the flow of the gas side at the rear part of the blade tends to be developed into turbulent flow, so that the heat exchange intensity of the outer surface of the part is very high, meanwhile, the air film cooling of the suction surface of the blade tends to be at the front part, the influence on the rear part is very small, the temperature of cooling gas is relatively high when the cooling gas absorbs heat in the air passage to the tail part, and the cooling effect is relatively small. At present, the vortex column row is an internal enhanced heat transfer structure commonly used in a tail edge area, and particularly, the fork row circular vortex column structure is widely applied to the design of a blade cooling structure. The research results of the literature on the development of the cooling structure of the air-cooled turbine blade of the aeroengine (propulsion technology) show that the cooling capacity of the conventional tail edge cooling structure gradually tends to be limited as the gas temperature of the aeroengine is continuously increased, and the ablation phenomenon of the high-pressure turbine blade frequently occurs in the tail edge area. Therefore, research into efficient cooling structures suitable for chord and trailing edge regions in turbine blades is an important measure to ensure stable operation of turbine blades.

In designing a turbine blade cooling structure, it is generally necessary to balance pressure loss and heat transfer effect, i.e. a cooling structure with higher heat exchange effect is often selected while minimizing internal air flow pressure loss. Therefore, development and innovation of a high-efficiency cooling structure of a turbine blade are important measures for ensuring stable operation of the turbine blade, and are very necessary and significant for development of an advanced high-performance aeroengine.

Disclosure of Invention

In order to solve the problems, the embodiment of the application provides a fish scale-shaped turbine blade cooling structure and a turbine blade, which are used for enhancing the internal convection heat transfer effect of the turbine blade and improving the countercurrent margin of a gas film hole, thereby achieving the purposes of improving the cooling efficiency of the blade and improving the temperature bearing capacity of the blade.

The embodiment of the application provides the following technical scheme: a fish scale turbine blade cooling structure, the cooling structure comprising:

a cool air supply cavity and a fish scale type turbine blade cooling channel; the starting end of the fish scale-shaped turbine blade cooling channel is provided with a plurality of straight inlet sections, the tail end of the fish scale-shaped turbine blade cooling channel is provided with a plurality of straight outlet sections, and the plurality of straight inlet sections are respectively communicated with the cold air supply cavity;

the fish scale turbine blade cooling channel is characterized in that a second fish scale vortex column assembly and a plurality of rows of first fish scale vortex column assemblies are arranged in a staggered mode between the starting end and the tail end of the fish scale turbine blade cooling channel, the second fish scale vortex column assembly comprises a plurality of second fish scale vortex columns arranged according to an array, the first fish scale vortex column assemblies comprise a plurality of first fish scale vortex columns arranged according to the array, edge gaps of adjacent vortex columns are mutually communicated, the upstream top end of each second fish scale vortex column is communicated with the straight inlet section, and the downstream tail end of each first fish scale vortex column is communicated with the straight outlet section to form a netlike cooling channel.

According to one embodiment of the application, the cooling structure further comprises a plurality of air film holes, wherein the center point of the initial end of each air film hole is arranged on a cooling channel at the upstream top end position of the first fish scale-shaped turbulent flow column;

the air film holes are obliquely arranged on the cooling channel at the upstream top end position of the first fish scale-shaped turbulent flow column, the diameter D of the air film holes is 0.25mm-0.50mm, and the inclination angle is 35-50 degrees.

According to one embodiment of the application, the first fish scale shaped turbulent flow column comprises an upstream inward concave windward section, an upper side diversion section and a lower side diversion section which are respectively connected with two ends of the windward section, wherein the tail end of the upper side diversion section is connected with the upper side diversion section, and the tail end of the lower side diversion section is connected with the lower side diversion section; the windward section, the upper side diversion section, the lower side diversion section, the upper side diversion section and the lower side diversion section surround and form the first fish scale-shaped turbulent flow column.

According to one embodiment of the application, the cross section of the first fish scale-shaped turbulent flow column is of a two-dimensional horizontal symmetrical structure; the cross sections of the upper side flow guiding section and the lower side flow guiding section of the first fish scale-shaped flow guiding column are elliptical arcs, the ratio of the long axis length a to the short axis length b of each elliptical arc is 1.85-2.25, the long axis length a of each elliptical arc is 3.5-8.5 mm, and the long axis direction of each elliptical arc is the horizontal direction;

the cross sections of the upper side flow dividing section and the lower side flow dividing section of the first fish scale-shaped flow dividing column are elliptical arcs, the ratio of the long axis length a1 to the short axis length b1 of each elliptical arc is 1.95-2.55, the long axis length a1 of each elliptical arc is 1.12-1.65, and the long axis direction of each elliptical arc is the horizontal direction.

According to one embodiment of the present application, a cross section of a windward section of the first fish scale shaped turbulent flow column is an elliptical arc, a ratio of a major axis length a2 to a minor axis length b2 of the elliptical arc is 1.00 to 1.15, the major axis length a2 of the elliptical arc is 0.15 to 0.45, and a major axis direction of the elliptical arc is a vertical direction;

the center P point of the windward-section elliptical arc of the first fish scale-shaped turbulent flow column and the center O point of the upper-side guide-section elliptical arc of the first fish scale-shaped turbulent flow column are at the same horizontal height, and the horizontal distance L between the two center points is 0.5 x a+0.175 x a2 to 0.5 x a+0.425 x a2.

According to one embodiment of the present application, a horizontal distance L1 between a center O1 point of an upper diversion section elliptical arc of the first fish scale shaped turbulent flow column and a center O point of an upper diversion section elliptical arc of the first fish scale shaped turbulent flow column is 0.325×a1 to 0.475×a1;

the vertical distance H between the center O1 point of the elliptical arc of the upper side shunting section of the first fish scale shaped turbulent flow column and the center O2 point of the elliptical arc of the lower side shunting section of the first fish scale shaped turbulent flow column is 0.625 to 0.95×b1.

According to one embodiment of the application, the second fish scale shaped turbulent flow column comprises an upstream outwards protruding windward diversion section, an upper diversion section and a lower diversion section which are respectively connected with two ends of the windward diversion section, wherein the tail end of the upper diversion section is connected with the upper diversion section, and the tail end of the lower diversion section is connected with the lower diversion section; the windward diversion section, the upper diversion section, the lower diversion section, the upper diversion section and the lower diversion section surround to form the second fish scale-shaped turbulent flow column.

According to one embodiment of the present application, the cross section of the windward diversion section of the second fish scale shaped turbulent flow column is an elliptical arc, and the elliptical arc of the cross section of the upper diversion section or the lower diversion section are the same ellipse;

the geometric dimensions of the upper side flow guide section, the lower side flow guide section, the upper side flow distribution section and the lower side flow distribution section of the second fish scale type flow disturbing column are the same as those of the corresponding part of the first fish scale type flow disturbing column.

According to one embodiment of the application, in the same fish scale-shaped turbulent flow column assembly, the radial distance S1 between two adjacent fish scale-shaped turbulent flow columns is 2.5mm to 13mm; the chord-wise distance S2 between two adjacent fish scale-shaped vortex column assemblies is 2.2mm to 14mm.

The application also provides a turbine blade, which comprises the fish scale-shaped turbine blade cooling structure, wherein the fish scale-shaped turbine blade cooling structure is arranged in the tail edge area and the mid-chord area of the turbine blade.

Compared with the prior art, the beneficial effects that above-mentioned at least one technical scheme that this description embodiment adopted can reach include at least: 1) The fish scale cooling structure can continuously turn the direction of cold air, so that strong secondary circulation is caused on the cross section, the development of a boundary layer can be obviously restrained, and the effect of enhancing internal heat exchange is achieved; 2) The cold air flow cross section along the path of the fish scale cooling structure is approximately the same, the phenomena of flow sudden expansion and throttling are avoided, the turning angle of the air flow is small, large-area backflow areas and the like are avoided, and the flow resistance is smaller; 3) Compared with the conventional blade cooling structure, the application has higher structural compactness, longer flow path of cold air and can provide more abundant primary heat transfer area; 4) Compared with the conventional cooling structure, the fish scale cooling structure is arranged in the tail edge area of the turbine blade, so that the internal heat exchange intensity of the tail edge area is integrally increased, the internal cooling effect is enhanced, and meanwhile, the connection area of the pressure surface and the suction surface of the blade is increased, so that the heat conduction between the pressure surface and the suction surface at the tail edge is enhanced, the temperature distribution between the pressure surface and the suction surface is balanced, the temperature gradient at the tail edge of the blade is effectively reduced, and the effects of reducing the thermal stress and effectively improving the intensity are achieved. 5) The inward concave windward section of the first fish scale-shaped vortex column can enable cooling gas to better generate stagnation, and is favorable for improving the pressure of the inlet of the gas film hole, so that the countercurrent margin of the outflow of the gas film hole is further improved, a better gas film cooling effect is realized, and the risk of gas backflow is prevented.

In summary, compared with the conventional blade cooling structure, the fish scale-shaped blade cooling structure has the characteristics of small flow loss, high heat exchange strength, high structural compactness and the like, can effectively increase the heat exchange strength inside the blade, and can stably and uniformly perform air film cooling, so that the temperature gradient of the blade is effectively reduced, and the temperature bearing capacity of the blade is improved.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings that are needed in the embodiments will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present application, and that other drawings can be obtained according to these drawings without inventive effort for a person skilled in the art.

FIG. 1 is a schematic cross-sectional view of a first fish scale shaped spoiler column according to an embodiment of the application;

FIG. 2 is another schematic cross-sectional view of a first fish scale shaped spoiler column according to an embodiment of the application;

FIG. 3 is a three-dimensional block diagram of a first fish scale shaped spoiler column according to an embodiment of the application;

FIG. 4 is a schematic cross-sectional view of a second fish scale shaped spoiler according to an embodiment of the application;

FIG. 5 is another schematic cross-sectional view of a second fish scale shaped spoiler column according to an embodiment of the application;

FIG. 6 is a three-dimensional block diagram of a second fish scale shaped spoiler column according to an embodiment of the application;

FIG. 7 is a schematic two-dimensional cross-sectional view of a fish scale turbine blade cooling structure in accordance with an embodiment of the application;

FIG. 8 is a three-dimensional block diagram of a fish scale turbine blade trailing edge cooling structure in accordance with an embodiment of the present application;

FIG. 9 is a three-dimensional block diagram of a turbine blade having a fish scale turbine blade cooling structure disposed in the trailing edge region in accordance with a first embodiment of the present application;

FIG. 10 is a three-dimensional block diagram of a cooling structure for a mid-chord region of a fish scale turbine blade in accordance with a second embodiment of the present application;

FIG. 11 is a three-dimensional block diagram of a turbine blade with a fish scale turbine blade cooling structure disposed in a mid-chord region in accordance with a second embodiment of the present application;

FIG. 12 is a graph showing the variation of the integrated heat transfer performance parameter η of a fish scale blade trailing edge cooling structure with the inlet Reynolds number Re according to an embodiment of the present application;

FIG. 13 is a mid-section velocity vector diagram of the internal gas flow of a cooling structure for a mid-chord region of a two-ichthyed blade in accordance with an embodiment of the present application;

the device comprises a 1-upper side diversion section, a 2-upper side diversion section, a 3-lower side diversion section, a 4-lower side diversion section, a 5-windward section, a 6-windward diversion section, a 7-first fish scale-shaped turbulence column, an 8-second fish scale-shaped turbulence column, a 9-straight inlet section, a 10-straight outlet section, an 11-cold air supply cavity, a 12-air film hole, a 13-turbine blade, a 14-fish scale-shaped cooling structure for a trailing edge area, a 15-fish scale-shaped cooling structure for a mid-chord area, a 16-trailing edge area, a 17-mid-chord area, a 101-first edge, a 102-second edge, a 103-third edge, a 104-fourth edge and a 105-fifth edge.

Detailed Description

Embodiments of the present application will be described in detail below with reference to the accompanying drawings.

Other advantages and effects of the present application will become apparent to those skilled in the art from the following disclosure, which describes the embodiments of the present application with reference to specific examples. It will be apparent that the described embodiments are only some, but not all, embodiments of the application. The application may be practiced or carried out in other embodiments that depart from the specific details, and the details of the present description may be modified or varied from the spirit and scope of the present application. It should be noted that the following embodiments and features in the embodiments may be combined with each other without conflict. All other embodiments, which can be made by those skilled in the art based on the embodiments of the application without making any inventive effort, are intended to be within the scope of the application.

As shown in fig. 1-11, an embodiment of the present application provides a fish scale turbine blade cooling structure, the cooling structure comprising: a cool air supply cavity 11, a fish scale type turbine blade cooling channel; the starting end of the fish scale-shaped turbine blade cooling channel is provided with a plurality of flat inlet sections 9, the tail end of the fish scale-shaped turbine blade cooling channel is provided with a plurality of flat outlet sections 10, and the flat inlet sections 9 are respectively communicated with the cold air supply cavity 11; the fish scale turbine blade cooling channel is characterized in that a second fish scale vortex column assembly and a plurality of rows of first fish scale vortex column assemblies are arranged in a staggered mode between the starting end and the tail end of the fish scale turbine blade cooling channel, the second fish scale vortex column assembly comprises a plurality of second fish scale vortex columns 8 which are arranged in an array mode, the first fish scale vortex column assembly comprises a plurality of first fish scale vortex columns 7 which are arranged in an array mode, edge gaps of adjacent vortex columns are mutually communicated, the upstream top end of each second fish scale vortex column 8 is communicated with the straight inlet section 9, and the downstream tail end of each first fish scale vortex column 7 is communicated with the straight outlet section 10 to form a net-shaped cooling channel.

The embodiment of the application provides a fish scale-shaped efficient cooling structure arranged in the tail edge area and the middle chord area of a turbine blade, which can effectively improve the comprehensive cooling efficiency and the temperature bearing capacity of the turbine blade.

In this embodiment, as shown in fig. 1 to 3, the first fish scale spoiler 7 includes an upstream inward concave windward section 5, an upper diversion section 1 and a lower diversion section 4 respectively connected to two ends of the windward section 5, wherein the tail end of the upper diversion section 1 is connected to the upper diversion section 2, and the tail end of the lower diversion section 4 is connected to the lower diversion section 3; the windward section 5, the upper diversion section 1, the lower diversion section 4, the upper diversion section 2 and the lower diversion section 3 surround and form the first fish scale-shaped turbulent flow column 7. As shown in fig. 1, the closed curve Sub>A-B-C-D-E-F-Sub>A is Sub>A schematic cross-sectional view of the first fish scale shaped spoiler column 7, and the symmetry axis of the cross-section is Sub>A straight line MN.

Specifically, the cross section of the first fish scale-shaped turbulent flow column 7 is of a two-dimensional horizontal symmetrical structure; the cross sections of the upper side flow guiding section 1 and the lower side flow guiding section 4 of the first fish scale-shaped flow guiding column 7 are elliptical arcs, the ratio of the long axis length a to the short axis length b of each elliptical arc is 1.85-2.25, the long axis length a of each elliptical arc is 3.5-8.5 mm, and the long axis direction of each elliptical arc is the horizontal direction;

the cross sections of the upper side diversion section 2 and the lower side diversion section 3 of the first fish scale-shaped vortex column 7 are elliptical arcs, the ratio of the long axis length a1 to the short axis length b1 of the elliptical arcs is 1.95-2.55, the long axis length a1 of the elliptical arcs is 1.12-1.65 x a, and the long axis direction of the elliptical arcs is the horizontal direction.

The cross section of the windward section 5 of the first fish scale-shaped turbulent flow column 7 is an elliptical arc, the ratio of the long axis length a2 to the short axis length b2 of the elliptical arc is 1.00-1.15, the long axis length a2 of the elliptical arc is 0.15-0.45 x a, and the long axis direction of the elliptical arc is the vertical direction;

the center point P of the elliptical arc of the windward section 5 of the first fish scale shaped turbulent flow column 7 and the center point O of the elliptical arc of the upper side guide section 1 of the first fish scale shaped turbulent flow column 7 are at the same horizontal height, and the horizontal distance L between the two center points is 0.5×a+0.175×a2 to 0.5×a+0.425×a2.

The horizontal distance L1 between the center O1 point of the elliptical arc of the upper side diversion section 2 of the first fish scale shaped turbulent flow column 7 and the center O point of the elliptical arc of the upper side diversion section 1 of the first fish scale shaped turbulent flow column 7 is 0.325×a1 to 0.475×a1;

the vertical distance H between the center O1 point of the elliptical arc of the upper side diversion section 2 of the first fish scale type vortex column 7 and the center O2 point of the elliptical arc of the lower side diversion section 3 of the first fish scale type vortex column 7 is 0.625×b1 to 0.95×b1.

In this embodiment, as shown in fig. 4 to 6, the second fish scale shaped spoiler column 8 includes an upstream windward diversion section 6, an upper diversion section 1 and a lower diversion section 4 respectively connected to two ends of the windward diversion section 6, wherein the tail end of the upper diversion section 1 is connected to the upper diversion section 2, and the tail end of the lower diversion section 4 is connected to the lower diversion section 3; the windward diversion section 6, the upper diversion section 1, the lower diversion section 4, the upper diversion section 2 and the lower diversion section 3 surround to form the second fish scale-shaped turbulent flow column 8. Ext> asext> shownext> inext> fig.ext> 4ext>,ext> theext> closedext> curveext> aext> -ext> Bext> -ext> Cext> -ext> Dext> -ext> Eext> -ext> Gext> -ext> aext> isext> aext> schematicext> crossext> -ext> sectionalext> viewext> ofext> theext> secondext> fishext> scaleext> shapedext> spoilerext> columnext> 8ext>,ext> andext> theext> symmetryext> axisext> ofext> theext> crossext> -ext> sectionext> isext> aext> straightext> lineext> mnext>.ext>

Specifically, the cross section of the windward diversion section 6 of the second fish scale type vortex column 8 is an elliptical arc, and the elliptical arc and the upper diversion section 1 or the lower diversion section 4 are the same ellipse;

the geometric dimensions of the upper diversion section 1, the lower diversion section 4, the upper diversion section 2 and the lower diversion section 3 of the second fish scale shaped turbulent flow column 8 are the same as those of the corresponding parts of the first fish scale shaped turbulent flow column 7.

In one embodiment of the present application, the cooling structure further includes a plurality of air film holes 12, and a center point of a start end of the air film hole 12 is disposed on a cooling channel at an upstream top end position of the first fish scale spoiler 7; the air film hole 12 is obliquely arranged on a cooling channel at the upstream top end position of the first fish scale type turbulent flow column 7, the diameter D of the air film hole 12 is 0.25mm to 0.50mm, and the inclination angle is 35 to 50 degrees.

In this embodiment, the first fish scale spoiler 7 further includes a first edge 101, a second edge 102, a third edge 103, a fourth edge 104, and a fifth edge 105, which are rounded edges, where the rounded radius r of the rounded edges is 0.10mm to 0.35mm.

The second fish scale vortex column 8 further comprises a first edge 101, a second edge 102 and a third edge 103, which are all rounded edges, and the rounded radius r of the rounded edges is 0.10mm to 0.35mm.

In the embodiment, in the same fish scale-shaped turbulent flow column assembly, the radial space S1 between two adjacent fish scale-shaped turbulent flow columns is 2.5mm-13mm; the chord-wise distance S2 between two adjacent fish scale-shaped vortex column assemblies is 2.2mm-14mm.

In this embodiment, the channel thickness t of the cooling structure is 0.3-2.5mm. The fish scale-shaped turbine blade cooling structure of the present embodiment is disposed in a trailing edge region and a mid-chord region of a turbine blade, as shown in fig. 9 and 11, fig. 9 is a three-dimensional structure diagram of a turbine blade in which a fish scale-shaped turbine blade cooling structure is disposed in the trailing edge region, and includes a turbine blade 13, a trailing edge region 16, and a fish scale-shaped cooling structure 14 for the trailing edge region; fig. 11 is a three-dimensional block diagram of a turbine blade provided with a fish scale shaped turbine blade cooling structure in the mid-chord region, comprising a turbine blade 13, a mid-chord region 17 and a fish scale shaped cooling structure 15 for the mid-chord region.

The application designs a fish scale-shaped turbine blade cooling structure arranged in a tail edge area by combining structural parameters of a certain engine turbine guide blade and cold air flow parameters, and respectively carries out comparative study on the flow state and heat exchange performance of internal cooling gas on the conventional blade tail edge cooling structure and the fish scale-shaped turbine blade cooling structure in the embodiment based on a flat plate model by a three-dimensional flow-solid coupling heat exchange numerical simulation method, and in order to comprehensively compare the heat exchange performance of the two heat exchange structures, the application defines a comprehensive heat exchange performance parameter eta which is used for representing the heat exchange strength corresponding to unit pressure drop, and specifically defines the following steps:

wherein, the average noose number of the Nu cooling structure, cp is the pressure loss coefficient between the inlet and outlet of the cooling structure.

Fig. 12 shows a graph of the integrated heat exchange performance parameter η of the pressure loss and heat exchange strength of the cooling structure of the scale-shaped turbine blade of the evaluation example as a function of the inlet reynolds number Re. It can be seen from fig. 12 that the overall heat exchange performance parameter η of the fish scale blade trailing edge cooling structure is always higher than that of the conventional blade trailing edge cooling structure, both in the low inlet reynolds number case and the high inlet reynolds number case. The three-dimensional numerical simulation result shows that the comprehensive heat exchange performance of the fish scale-shaped blade tail edge cooling structure is 19.7% higher than that of the conventional blade tail edge cooling structure in the flow parameter range (Re=8200-31500) of the blade tail edge. Therefore, the fish scale-shaped blade cooling structure is a preferable structure and is a cooling structure with higher comprehensive heat exchange performance. When the cooling structure of the tail edge of the blade is designed, the contradiction between pressure loss and heat transfer effect is generally required to be balanced, and the cooling structure with better cooling effect is selected under the condition of utilizing the residual pressure loss of the tail edge of the blade as much as possible.

FIG. 13 is a mid-section velocity vector diagram of the internal gas flow of a cooling structure for the mid-chord region of a two-ichthyed blade in accordance with an embodiment of the present application, from which it can be seen that: 1) The fish scale turbine blade cooling structure of the embodiment of the application can continuously turn the direction of cold air, so that strong secondary circulation is caused on the cross section, the development of a boundary layer can be obviously restrained, and the effect of enhancing internal heat exchange is achieved; 2) The scale-shaped cooling structure has the advantages that the along-path cold air flow cross section is approximately the same along the path, the phenomena of flow sudden expansion and throttling are avoided, the turning angle of the air flow is small, large-area backflow areas and the like are avoided, and the flow resistance is smaller; 3) The inward concave windward section of the first fish scale-shaped vortex column can enable cooling gas to better generate stagnation, and is favorable for improving the pressure of the inlet of the gas film hole, so that the countercurrent margin of the outflow of the gas film hole is further improved, a better gas film cooling effect is realized, and the risk of gas backflow is prevented.

Therefore, the fish scale-shaped turbine blade cooling structure is a preferable structure and is a cooling structure with higher comprehensive heat exchange performance. Compared with the conventional blade cooling structure, the fish scale cooling structure provided by the embodiment of the application has higher compactness, longer flow path of cold air and capability of providing a richer primary heat transfer area. In addition, the fish scale cooling structure provided by the embodiment of the application is arranged in the tail edge area of the turbine blade, so that the internal heat exchange intensity of the tail edge area is integrally increased, the internal cooling effect is enhanced, and meanwhile, the connection area of the pressure surface and the suction surface of the blade is increased, so that the heat conduction between the pressure surface and the suction surface at the tail edge is enhanced, the temperature distribution between the pressure surface and the suction surface is balanced, the temperature gradient at the tail edge of the blade is effectively reduced, and the effects of reducing the thermal stress and effectively improving the intensity are achieved.

The foregoing is merely illustrative of the present application, and the present application is not limited thereto, and any changes or substitutions easily contemplated by those skilled in the art within the scope of the present application should be included in the present application. Therefore, the protection scope of the application is subject to the protection scope of the claims.

Claims (10)

1. A fish scale turbine blade cooling structure, the cooling structure comprising:

a cold air supply cavity (11) and a fish scale type turbine blade cooling channel; the starting end of the fish scale-shaped turbine blade cooling channel is provided with a plurality of flat inlet sections (9), the tail end of the fish scale-shaped turbine blade cooling channel is provided with a plurality of flat outlet sections (10), and the flat inlet sections (9) are respectively communicated with the cold air supply cavity (11);

the fish scale turbine blade cooling channel is characterized in that a second fish scale vortex column assembly and a plurality of rows of first fish scale vortex column assemblies are arranged in a staggered mode between the starting end and the tail end of the fish scale turbine blade cooling channel, the second fish scale vortex column assembly comprises a plurality of second fish scale vortex columns (8) which are arranged in an array mode, the first fish scale vortex column assembly comprises a plurality of first fish scale vortex columns (7) which are arranged in an array mode, edge gaps of adjacent vortex columns are mutually communicated, the upstream top end of each second fish scale vortex column (8) is communicated with the straight inlet section (9), and the downstream tail end of each first fish scale vortex column (7) is communicated with the straight outlet section (10) to form a netlike cooling channel.

2. The fish scale turbine blade cooling structure according to claim 1, further comprising a plurality of film holes (12), a center point of a start end of the film holes (12) being disposed on a cooling channel at an upstream top end position of the first fish scale spoiler column (7);

the air film holes (12) are obliquely arranged on a cooling channel at the upstream top end position of the first fish scale-shaped turbulent flow column (7), the diameter D of each air film hole (12) is 0.25-0.50 mm, and the inclination angle is 35-50 degrees.

3. The fish scale turbine blade cooling structure according to claim 1, wherein the first fish scale vortex column (7) comprises an upstream inward concave windward section (5), an upper side diversion section (1) and a lower side diversion section (4) which are respectively connected with two ends of the windward section (5), the tail end of the upper side diversion section (1) is connected with the upper side diversion section (2), and the tail end of the lower side diversion section (4) is connected with the lower side diversion section (3); the windward section (5), the upper side diversion section (1), the lower side diversion section (4), the upper side diversion section (2) and the lower side diversion section (3) surround and form the first fish scale-shaped turbulent flow column (7).

4. A fish scale turbine blade cooling structure according to claim 3, characterized in that the cross section of the first fish scale shaped turbulence column (7) is a two-dimensional horizontal symmetrical structure; the cross sections of the upper side flow guiding section (1) and the lower side flow guiding section (4) of the first fish scale-shaped flow guiding column (7) are elliptical arcs, the ratio of the long axis length a to the short axis length b of each elliptical arc is 1.85-2.25, the long axis length a of each elliptical arc is 3.5-8.5 mm, and the long axis direction of each elliptical arc is the horizontal direction;

the cross sections of the upper side flow dividing section (2) and the lower side flow dividing section (3) of the first fish scale-shaped flow-disturbing column (7) are elliptical arcs, the ratio of the long axis length a1 to the short axis length b1 of each elliptical arc is 1.95-2.55, the long axis length a1 of each elliptical arc is 1.12-1.65 x a, and the long axis direction of each elliptical arc is the horizontal direction.

5. The fish scale turbine blade cooling structure according to claim 4, characterized in that the cross section of the windward section (5) of the first fish scale vortex column (7) is an elliptical arc, and the ratio of the major axis length a2 to the minor axis length b2 of the elliptical arc is 1.00 to 1.15, the major axis length a2 of the elliptical arc is 0.15 to 0.45 x a, and the major axis direction of the elliptical arc is vertical;

the center P point of the elliptical arc of the windward section (5) of the first fish scale type vortex column (7) and the center O point of the elliptical arc of the upper side flow guiding section (1) of the first fish scale type vortex column (7) are at the same horizontal height, and the horizontal distance L between the two center points is 0.5 x a+0.175 x a2 to 0.5 x a+0.425 x a2.

6. The fish scale turbine blade cooling structure according to claim 4, characterized in that the horizontal distance L1 between the center O1 point of the elliptical arc of the upper side flow diversion section (2) of the first fish scale shaped flow diversion column (7) and the center O point of the elliptical arc of the upper side flow diversion section (1) of the first fish scale shaped flow diversion column (7) is 0.325 x a1 to 0.475 x a1;

the vertical distance H between the center O1 point of the elliptical arc of the upper side shunting section (2) of the first fish scale shaped turbulent flow column (7) and the center O2 point of the elliptical arc of the lower side shunting section (3) of the first fish scale shaped turbulent flow column (7) is 0.625 to 0.95×b1.

7. The fish scale turbine blade cooling structure according to claim 4, wherein the second fish scale vortex column (8) comprises an upstream windward diversion section (6), an upper diversion section (1) and a lower diversion section (4) which are respectively connected with two ends of the windward diversion section (6), wherein the tail end of the upper diversion section (1) is connected with the upper diversion section (2), and the tail end of the lower diversion section (4) is connected with the lower diversion section (3); the windward diversion section (6), the upper diversion section (1), the lower diversion section (4), the upper diversion section (2) and the lower diversion section (3) surround and form the second fish scale-shaped turbulent flow column (8).

8. The fish scale turbine blade cooling structure according to claim 7, characterized in that the cross section of the windward diversion section (6) of the second fish scale vortex column (8) is an elliptical arc, and the elliptical arc of the cross section of the upper diversion section (1) or the lower diversion section (4) are the same ellipse;

the geometric dimensions of the upper side flow guide section (1), the lower side flow guide section (4), the upper side flow distribution section (2) and the lower side flow distribution section (3) of the second fish scale-shaped flow disturbing column (8) are the same as those of the corresponding parts of the first fish scale-shaped flow disturbing column (7).

9. The cooling channel of a fish scale turbine blade of claim 1, wherein the radial spacing S1 of two adjacent fish scale turbulators within the same fish scale turbulator assembly is 2.5mm to 13mm; the chord-wise distance S2 between two adjacent fish scale-shaped vortex column assemblies is 2.2mm to 14mm.

10. A turbine blade comprising a fish scale turbine blade cooling structure as claimed in any one of claims 1 to 9, said fish scale turbine blade cooling structure being disposed in the region of the trailing edge, mid chord of the turbine blade.