A turbine guide vane structure and blade structure

Abstract

This invention discloses a turbine guide vane channel structure and blade structure, belonging to the field of aero-engine technology. The turbine guide vane channel structure includes a first flow channel arranged along the airflow direction, formed by rotating a first upstream profile and a second upstream profile around the turbine axis. The angle between the line connecting the two endpoints of the first upstream profile and the turbine axis is between 25° and 40°, and the angle between the line connecting the two endpoints of the second upstream profile and the turbine axis is between 0° and 15°. By employing a first flow channel with a large inclination angle, the axial length of the direct-flow combustion chamber and the high-pressure turbine connected to it is effectively shortened, resulting in a more compact and lighter overall engine. Furthermore, the rotor length and span between support points are short, resulting in good rotor bending rigidity and excellent rotor dynamic characteristics.

Description

Technical Field

[0001] This invention belongs to the field of aerospace engine technology, specifically relating to a turbine guide vane structure and a blade structure. Background Technology

[0002] In modern high-power turboshaft and turboprop engines, as the intake air volume increases, a direct-flow combustion chamber is typically used to improve the combustion chamber's heat capacity. This results in a significant increase in the engine's overall axial length and weight compared to a recirculating combustion chamber design. Furthermore, compared to a recirculating combustion chamber, the height difference between the combustion chamber outlet and the inlet of the downstream gas turbine's first-stage rotor is significantly increased with the direct-flow combustion chamber design. To reduce this height difference, the radius and height of the gas turbine's first-stage rotor need to be increased accordingly, leading to a higher tangential velocity in the gas turbine rotor. This increased blade root stress has a significant adverse impact on structural strength. Simultaneously, the thickness and height of the turbine disk also need to be increased accordingly, resulting in an increase in the disk's weight.

[0003] To reduce the radial height difference between the combustion chamber outlet and the high-pressure turbine rotor, one feasible approach is to increase the downward tilt angle of the direct-flow combustion chamber. However, this would drastically reduce the flow area of ​​the high-pressure guide vane inlet section along the flow direction, significantly increasing the convergence of the guide vane cascade channel. This would lead to larger changes in the inlet and outlet velocities of the guide vane, making it more difficult to organize the flow inside the high-pressure turbine guide vane cascade channel, increasing the intensity of secondary flow in the end region, and increasing flow losses in the end region. In addition, due to the inconsistent tilt angles of the inner and outer flow channels, the radial non-uniformity at the guide vane outlet would also increase, which would have a significant adverse impact on the normal operation of the downstream rotor blades. Summary of the Invention

[0004] The purpose of this invention is to provide a turbine guide vane channel structure and blade structure to solve the problems mentioned in the background art regarding the use of existing turbine guide vane channels and blades.

[0005] To achieve the above objectives, the present invention provides the following technical solution: a turbine guide channel structure for guiding the combustion gas flowing out of the direct-flow combustion chamber, the channel comprising:

[0006] The first flow channel is formed by rotating the first upstream profile and the second upstream profile around the turbine axis for one revolution. The angle between the line connecting the two ends of the first upstream profile and the turbine axis is between 25° and 40°, and the angle between the line connecting the two ends of the second upstream profile and the turbine axis is between 0° and 15°.

[0007] Preferably, the first profile includes an inclined section, a smooth section, and a contraction section arranged sequentially along the airflow direction, wherein the rate of change of the inclination angle of the inclined section and the contraction section is greater than the rate of change of the inclination angle of the smooth section.

[0008] Preferably, the tilt angle of the inclined segment is between 65° and 75°, the tilt angle of the contraction segment is between 40° and 55°, and the difference between the tilt angle of the smooth segment and the tilt angle of the second upstream profile is between -2° and 2°.

[0009] Preferably, the channel further includes a second flow channel, the first flow channel and the second flow channel are arranged sequentially along the airflow direction, the second flow channel is formed by rotating a first downstream profile and a second downstream profile around the turbine axis for one revolution, and both the first downstream profile and the second downstream profile extend along the turbine axis.

[0010] Preferably, the inclination angles of both the first downstream profile and the second downstream profile are between 0° and 2°.

[0011] Preferably, the tilt angle of the tilt segment gradually decreases along the airflow direction.

[0012] Preferably, the inclination angle of the contraction section first decreases and then increases along the airflow direction.

[0013] Preferably, the second upstream profile and the second downstream profile are smoothly connected, and the inclination angle of the second upstream profile is greater than the inclination angle of the second downstream profile.

[0014] Preferably, the inclination angles of the second upstream profile and the second downstream profile both gradually decrease along the airflow direction.

[0015] A turbine guide vane structure, wherein the vanes are circumferentially evenly spaced in the smooth section and the constricted section of the aforementioned channel, and the leading edge and trailing edge of the vanes are inclined in the direction of airflow.

[0016] Preferably, the angle between the leading edge and the turbine axis is between 70° and 80°, and the angle between the trailing edge and the turbine axis is between 75° and 85°.

[0017] Compared with the prior art, the beneficial effects of the present invention are:

[0018] 1. By designing a first flow channel with a large inclination angle, this application can effectively shorten the axial length of the DC combustion chamber and the high-pressure turbine connected to it, thereby making the whole machine more compact and lighter; and the rotor length and span between the support points are short, the rotor bending rigidity is good, and the rotor dynamic characteristics are good.

[0019] 2. By adopting a three-segment profile design consisting of an inclined section, a smooth section, and a contraction section on the first upstream profile forming the first flow channel, the starting position of the secondary flow in the stator blade end region is significantly delayed, the height of the secondary flow influence is reduced, and the proportion of the low-loss mainstream region height to the total blade height is significantly increased, thereby effectively weakening the intensity of the secondary flow in the guide vane end region and reducing the flow loss inside the guide vane.

[0020] 3. The flow in the main flow area at the outlet of the guide vane is smoother and the radial flow is more uniform, which creates a good inlet flow field for the downstream rotor blades. This helps to reduce rotor flow and provides a strong guarantee for the high-pressure turbine to achieve higher efficiency, thereby reducing the overall fuel consumption of the engine.

[0021] 4. By adopting the structure designed in this application, the height difference between the combustion chamber outlet and the rotor blade flow channel can be increased accordingly, so that the turbine rotor can use a lower flow channel height, the rotor blade root stress is small, and the blade strength and life are high; the height and thickness of the wheel disk can be reduced accordingly, the wheel disk is lightweight, and the cost is low. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the overall structure of the turbine guide vane channel and the blade structure of the present invention;

[0023] Figure 2 This is a schematic diagram of the channel structure and blade structure angles of the present invention;

[0024] Figure 3 This is a schematic diagram of the channel structure of the present invention;

[0025] Figure 4 For the experimental simulation of this invention Figure 1 ;

[0026] Figure 5 For the experimental simulation of this invention Figure 2 .

[0027] In the diagram: 10, first flow channel; 20, second flow channel; 100, first profile; 101, first upstream profile; 101a, angled section; 101b, smooth section; 101c, contraction section; 102, first downstream profile; 102a, straight section; 200, second profile; 201, second upstream profile; 202, second downstream profile; 300, blade; 300a, blade leading edge; 300b, blade trailing edge. Detailed Implementation

[0028] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0029] A turbine guide channel structure (hereinafter referred to as the channel) is disposed between the outlet of the DC combustion chamber and the turbine rotor flow passage, for guiding the combustion gas flowing out of the DC combustion chamber. In the following description, the upstream of a component in the channel refers to the end near the outlet of the DC combustion chamber, and the downstream of a component refers to the end near the turbine rotor flow passage. (Refer to...) Figure 1 and 2 The main body of this channel consists of a stator blade flow channel (hereinafter referred to as the first flow channel 10) and a rotor blade flow channel (hereinafter referred to as the second flow channel 20). Specifically, the channel is roughly annular, that is, it is formed by rotating the inner end wall profile (hereinafter referred to as the first profile 100) and the outer end wall profile (hereinafter referred to as the second profile 200) around the engine axis O (hereinafter also referred to as the turbine axis) for one revolution. Figure 2 Figure 1 is a cross-sectional view of the channel. As shown in the figure, both the first profile 100 and the second profile 200 of the channel are smooth curves, and there is an inflection point on both the first profile 100 and the second profile 200. This inflection point of the first profile 100 and the second profile 200 constitutes the boundary point between the first flow channel 10 and the second flow channel 20. For ease of description, the boundary point on the first profile 100 and the second profile 200 are respectively referred to as the first boundary point and the second boundary point, and the section between the upstream endpoint of the first profile 100 and the first boundary point is correspondingly referred to as the first upstream profile 10. 1. The section between the downstream end point and the first dividing point of the first profile 100 is denoted as the first downstream profile 102. The section between the upstream end point and the second dividing point of the second profile 200 is denoted as the second upstream profile 201. The section between the downstream end point and the second dividing point of the second profile 200 is denoted as the second downstream profile 202. At this time, the first flow channel 10 is formed by rotating the first upstream profile 101 and the second upstream profile 201 around the turbine axis O once. The second flow channel 20 is formed by rotating the first downstream profile 102 and the second downstream profile 202 around the turbine axis O once.

[0030] In the following description, the angle between the tangent at any point in the first profile 100 and the second profile 200 and the engine axis is defined as the tilt angle of that point. At the same time, the set of angles between the tangents at all points in any segment of the first profile 100 and the second profile 200 and the engine axis is defined as the tilt angle of that segment. For example, if the tilt angle of a segment is between A and B (inclusive), it means that the tilt angle of any point in that segment is between A and B.

[0031] Reference Figure 2In some embodiments of the channel, the angle between the line connecting the two ends of the first upstream profile 101 and the turbine axis is between 25° and 40°, and the angle between the line connecting the two ends of the second upstream profile 201 and the turbine axis is between 0° and 15°. Both the first downstream profile 102 and the second downstream profile 202 are arranged along the turbine axis. In other embodiments of the channel, the inclination angles of both the first downstream profile 102 and the second downstream profile 202 are between 0° and 2°. The specific values ​​of the angles between the two ends of the first upstream profile 101 and the turbine axis, and the angles between the two ends of the second upstream profile 201 and the turbine axis, are selected based on the height difference between the combustion chamber outlet and the rotor blade flow channel (i.e., the second flow channel 20). Specifically, refer to... Figure 1 The height difference between the combustion chamber outlet and the rotor blade flow channel is defined as the radius difference between the upstream endpoint of the first upstream profile 101 and each position point of the first downstream profile 102, which will be denoted by h. The radius value of each position point of the first downstream profile 102 (i.e., the distance between the coaxial lines O of each position point of the first downstream profile 102) is denoted as r1. In some embodiments of the channel, the ratio of h to r1 is between 0.13 and 0.18.

[0032] In some embodiments of the channel, refer to Figure 3 The first profile 100 of the channel includes an angled section 101a, a smooth section 101b, a contraction section 101c, and a straight section 102a. The angled section 101a, smooth section 101b, and contraction section 101c together constitute the first upstream profile 101, while the straight section 102a constitutes the first downstream profile 102. Specifically, the angled section 101a is connected upstream to the outlet of the direct-flow combustion chamber, and the straight section 102a is connected to the outer end wall of the rotor. The angled section 101a, smooth section 101b, contraction section 101c, and straight section 102a are sequentially arranged along the gas flow direction. Figure 3 Points P0, P1, P2, and P3 exist on the first profile 100. P0 constitutes the upstream endpoint of the inclined segment 101a, P1, P2, and P3 constitute the inflection point on the first profile 100, and P3 constitutes the aforementioned first dividing point. More specifically, the inclined segment 101a constitutes the segment between P0 and P1 in the first profile 100, the smooth segment 101b constitutes the segment between P1 and P2, the contracting segment 101c constitutes the segment between P2 and P3, and the straight segment 102a constitutes the segment between P3 and the downstream endpoint of the first profile 100.

[0033] Back Figure 3The tilt angle settings of the tilt section 101a, smooth section 101b, contraction section 101c, and straight section 102a are further explained. The tilt angle α1 of the tilt section 101a is between 65° and 75°, and the tilt angle α1 of the tilt section 101a gradually decreases along the airflow direction. The tilt angle α2 of the smooth section 101b is approximately the same as the tilt angle of the second profile 200 (explained in detail later). The tilt angle of the contraction section 101c is between 40° and 55°. The straight section 102a is approximately parallel to the engine axis. Specifically, the tilt angle of the straight section 102a is between 0° and 2°. In the tilt section 101a connected to the combustion chamber, taking advantage of the low Mach number at the combustion chamber exit, a downward tilt angle of 65° to 75° is adopted, which makes the high-pressure vortex... The area of ​​the inlet section of the guide vane shrinks sharply, increasing the flow velocity and improving the acceleration capability of the guide vane while preventing the boundary layer flow loss from increasing too rapidly. In the smooth section 101b, the inclination angles of the first profile 100 and the second profile 200 of the guide vane channel are basically the same, making the internal flow field of the guide vane as uniform as possible radially and reducing the intensity of secondary flow in the end region. In the contraction section 101c, a sharply contracting outer end wall configuration is adopted to increase the Mach number at the guide vane exit and improve the work capacity of the high-pressure turbine. The channel with this structure can avoid the excessive acceleration of the guide vane that occurs when directly using the large-angle first profile 100, which leads to flow separation at the blade exit section and increases the influence range of the secondary flow intensity in the end region, crowding out the mainstream flow region with smaller flow losses and increasing the flow loss of the guide vane.

[0034] Back Figure 3 Referring to the diagram, the second type of line 200 has an inflection point P4, which constitutes the aforementioned second dividing point and divides the second type of line 200 into a smoothly connected second upstream type line 201 and a second downstream type line 202. The second upstream type line 201 forms the segment between the inflection point P4 and the upstream endpoint of the second type of line 200, and the second downstream type line 202 forms the segment between the inflection point P4 and the downstream endpoint of the second type of line 202. The inclination angle of the second upstream type line 201 is slightly larger than that of the second downstream type line 202; that is, the minimum inclination angle of the second upstream type line 201 is greater than the minimum inclination angle of the second downstream type line 202. In other words, the inclination angle of the second type of line 200 gradually decreases along the flow direction of the gas, and the absolute value of the difference between the inclination angle α5 of the second upstream type line 201 and the inclination angle α2 of the smooth segment 101b in the first type of line 100 is no greater than 2°. ;

[0035] A turbine guide vane structure (hereinafter referred to as vane 300) is provided. The vane 300 is circumferentially and evenly spaced within the smooth section 101b and the constricted section 101c of the aforementioned channel. The guide vane adopts a certain sweep design, that is, the leading edge 300a and the trailing edge 300b of the vane are tilted at a certain angle in the direction of airflow. After tilting, the angle between the leading edge 300a of the vane and the engine axis is between 70° and 80°, and the angle between the trailing edge 300b of the vane and the engine axis is between 75° and 85°.

[0036] Figure 4 and 5 The flow field calculation results of the guide vane after adopting the present invention show that the starting position of the secondary flow in the end region is significantly delayed, the influence height of the secondary flow is reduced, and the proportion of the height of the low-loss mainstream region to the total blade height is significantly increased, thereby effectively weakening the intensity of the secondary flow in the end region of the guide vane and reducing the flow loss inside the guide vane. In addition, the streamlines on the surface of the blade in the mainstream region are relatively straight, and no streamline bending phenomenon is observed. This indicates that the flow in the mainstream region is smoother and the radial flow is more uniform. This also creates a good inlet flow field for the downstream rotor blades, which is conducive to reducing rotor flow and thus provides a strong guarantee for the high-pressure turbine to obtain higher efficiency, thereby reducing the overall fuel consumption rate of the engine.

[0037] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A turbine guide channel structure, disposed between the outlet of a direct-flow combustion chamber and the turbine rotor flow channel, for guiding the combustion gas flowing out of the direct-flow combustion chamber, characterized in that: The channel structure includes: The first flow channel is formed by rotating the first upstream profile and the second upstream profile around the turbine axis for one revolution. The angle between the line connecting the two ends of the first upstream profile and the turbine axis is between 25° and 40°, and the angle between the line connecting the two ends of the second upstream profile and the turbine axis is between 0° and 15°. The first upstream profile includes an inclined section, a smooth section, and a contraction section arranged sequentially along the airflow direction, wherein the rate of change of the inclination angle of the inclined section and the contraction section is greater than the rate of change of the inclination angle of the smooth section; The tilt angle of the tilt segment is between 65° and 75°, the tilt angle of the contraction segment is between 40° and 55°, the difference between the tilt angle of the smooth segment and the tilt angle of the second upstream profile is between -2° and 2°, the tilt angle of the tilt segment is the set of angles between the tangents at all points on the tilt segment and the engine axis, the tilt angle of the contraction segment is the set of angles between the tangents at all points on the contraction segment and the engine axis, the tilt angle of the smooth segment is the set of angles between the tangents at all points on the smooth segment and the engine axis, and the tilt angle of the second upstream profile is the set of angles between the tangents at all points on the second upstream profile and the engine axis.

2. The turbine guide channel structure according to claim 1, characterized in that: The channel also includes a second flow channel. The first flow channel and the second flow channel are arranged sequentially along the airflow direction. The second flow channel is formed by rotating a first downstream profile and a second downstream profile around the turbine axis for one revolution. Both the first downstream profile and the second downstream profile extend along the turbine axis.

3. The turbine guide channel structure according to claim 2, characterized in that: The inclination angles of both the first downstream profile and the second downstream profile are between 0° and 2°.

4. The turbine guide channel structure according to claim 1, characterized in that: The tilt angle of the tilt segment gradually decreases along the airflow direction.

5. The turbine guide channel structure according to claim 1, characterized in that: The inclination angle of the contraction section first decreases and then increases along the airflow direction.

6. The turbine guide channel structure according to claim 3, characterized in that: The second upstream profile and the second downstream profile are smoothly connected, and the inclination angle of the second upstream profile is greater than that of the second downstream profile.

7. A turbine guide channel structure according to claim 3, characterized in that: The inclination angles of the second upstream profile and the second downstream profile gradually decrease along the airflow direction.

8. A turbine guide vane structure, characterized in that: The blades are circumferentially evenly spaced in the smooth and constricted sections of the channel structure according to any one of claims 1-7, and the leading and trailing edges of the blades are inclined in the direction of airflow.

9. A turbine guide vane structure according to claim 8, characterized in that: The angle between the leading edge and the turbine axis is between 70° and 80°, and the angle between the trailing edge and the turbine axis is between 75° and 85°.

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