Blade assemblies and their design methods and gas turbines

Abstract

This disclosure relates to a blade assembly, its design method, and a gas turbine. The blade assembly includes a blade and an endwall component. The blade is disposed on the endwall component, and a tangential channel and a flow channel are formed on the endwall surface of the endwall component. The tangential channel is located at the leading edge of the blade, and the flow channel is located on the suction side of the blade. The tangential and flow channels connect to form a smooth L-shaped channel. By machining a smooth L-shaped channel on the endwall surface of the endwall component, a robust flow vortex can be induced near the endwall, thereby controlling the secondary flow at the endwall. This produces a flow control effect similar to that of bladed and wedge-shaped vortex generators, thereby reducing end-area flow losses and improving the aerodynamic efficiency of the turbomachinery. Furthermore, it is easier to manufacture than conventional vortex generators and does not introduce serious structural reliability problems.

Description

Technical Field

[0001] This disclosure relates to a blade assembly, a design method thereof, and a gas turbine. Background Technology

[0002] The statements herein are provided only as background information in connection with this disclosure and do not necessarily constitute related technology.

[0003] Endwall secondary flow is one of the main sources of flow losses in turbomachinery such as compressors and turbines, and a crucial factor determining their efficiency. In aero-gas turbine engines, compressors and turbines are typically designed for high loads to reduce component weight, shorten engine axial dimensions, decrease the number of parts, and lower maintenance costs. However, endwall secondary flow in turbomachinery intensifies with increasing aerodynamic load, leading to a decrease in component aerodynamic efficiency. Therefore, developing endwall secondary flow control technologies will help overcome the constraint of endwall secondary flow on increasing turbomachinery load levels.

[0004] Vortex generators are flow control devices that generate vortices to influence the flow field. Common vortex generators mainly consist of a triangular ramp (wedge-shaped vortex generator) placed on a surface or small blades arranged at a certain angle of attack to the incoming flow direction (blade-type vortex generator). When a vortex generator is placed on the endwall of turbomachinery, the generated flow-directed vortices can weaken and intercept the secondary flow at the endwall, thereby reducing flow losses in the end region. Related technologies have proposed an asymmetric wedge-shaped vortex generator and its design method for flow control of compressor blades. In this technical solution, the optimal vortex generator scheme can reduce the total pressure loss of the blade cascade by 21.03%. However, in components where endwall secondary flow phenomena are severe, such as the last stage of a high-pressure compressor and high-pressure turbine in aero-engines, the corresponding vortex generator geometry becomes very small due to the small flow channel size. Small-sized vortex generators are not only difficult to manufacture with precision, but their sharp geometric corners can also lead to structural reliability problems such as stress concentration and high-temperature ablation (in high-pressure turbines). Summary of the Invention

[0005] One of the technical problems to be solved by this disclosure is to provide a blade assembly and its design method, as well as a gas turbine, which can improve aerodynamic efficiency and structural reliability.

[0006] Some embodiments of this disclosure provide a blade assembly, including: a blade and an endwall member, wherein a tangential channel and a flow channel are formed on the endwall surface of the endwall member; wherein the blade is disposed on the endwall member, the tangential channel is located at the leading edge of the blade, the flow channel is located on the suction side of the blade, and the tangential channel and the flow channel are connected to form a smooth L-shaped channel.

[0007] In some embodiments, the tangential channel extends in a direction tangential to the leading edge of the blade, and the flow channel extends along the back line of the blade.

[0008] In some embodiments, the cross-sections of both the tangential channel and the flow channel are configured as arcuate lines.

[0009] In some embodiments, in the standard shape space, the longitudinal sections of both the tangential channel and the flow channel are configured as piecewise curves with arc-shaped lines on both sides and a horizontal straight line in the middle.

[0010] In some embodiments, the curved line is configured as a sine line.

[0011] Some embodiments of this disclosure provide a design method for the aforementioned blade assembly, including:

[0012] The standard design space is set as follows: X, Y, and Z represent the radial, circumferential, and central arc lines of the impeller mechanical channel standard space, as well as their upstream and downstream extensions, respectively; Y=0 represents the central arc line of the blade and its upstream and downstream extensions, Y=1 represents the central arc line of adjacent blades and its upstream and downstream extensions; Z=0 and Z=1 represent the leading and trailing edge lines of the blade, Z<0 represents the upstream region of the blade, and Z>1 represents the downstream region of the blade.

[0013] The cylindrical coordinate system of the end wall region is defined as (r, θ, z). The actual surface coordinates of the end wall component and the surface coordinates within the standard shaping range have the following transformation relationship:

[0014]

[0015] Where δ is the thickness of the incoming boundary layer, r endwall Here, θ is the radial coordinate of the endwall, N is the number of blades, and θ is the radial coordinate of the end camber Let c be the circumferential coordinates of the mid-arc line and its extension of the endwall airfoil. z Z is the axial chord length of the endwall airfoil. LE δ represents the axial coordinate of the leading edge of the blade. When the end wall component is a hub, the sign before δ is "-"; when the end wall component is a casing, the sign before δ is "+".

[0016] Some embodiments of this disclosure provide a design method for the aforementioned blade assembly, including:

[0017] The standard design space is set as follows: X, Y, and Z represent the radial, circumferential, and central arc lines of the impeller mechanical channel standard space, as well as their upstream and downstream extensions, respectively; Y=0 represents the central arc line of the blade and its upstream and downstream extensions, Y=1 represents the central arc line of adjacent blades and its upstream and downstream extensions; Z=0 and Z=1 represent the leading and trailing edge lines of the blade, Z<0 represents the upstream region of the blade, and Z>1 represents the downstream region of the blade.

[0018] The Cartesian coordinate system of the end wall region is defined as (x, y, z), where x represents the spanwise direction, y represents the tangential direction, and z represents the axial direction. The actual surface coordinates of the end wall component and the surface coordinates within the standard shaping range have the following transformation relationship:

[0019]

[0020] Where δ is the thickness of the incoming boundary layer, x endwall Here are the radial coordinates of the endwall, s is the grid pitch, and y is the radial coordinate of the endwall. camber Let c be the tangential coordinate of the mid-arc line of the blade and its extension. z Let z be the axial chord length of the blade. LE is the axial coordinate of the leading edge of the blade.

[0021] In some embodiments, the dimensionless width of the tangential channel is T1=0.16; the dimensionless length of the tangential channel is L1+T2=0.53; the dimensionless width of the flow channel is T2=0.35; the dimensionless length of the flow channel is L2+T1=0.87; the dimensionless distance between the flow channel and the arc of the blade is D=0.10; and the maximum dimensionless depth of the L-shaped channel is H=0.38.

[0022] Some embodiments of this disclosure provide a gas turbine including the aforementioned blade assembly.

[0023] In the technical solution disclosed herein, by machining a smooth L-shaped channel on the endwall surface of the endwall component, a robust flow vortex can be induced near the endwall, thereby achieving control of the secondary flow at the endwall. This can produce a flow control effect similar to that of blade-type and wedge-shaped vortex generators, thereby reducing flow losses in the end region and improving the aerodynamic efficiency of the impeller. Furthermore, it is easier to manufacture than conventional vortex generators and does not cause serious structural reliability problems. Attached Figure Description

[0024] To more clearly illustrate the technical solutions in the embodiments or related technologies of this disclosure, the accompanying drawings used in the description of the embodiments or related technologies will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this disclosure. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0025] Figure 1 This is a schematic diagram of the configuration of some embodiments of the blade assembly according to the present disclosure;

[0026] Figure 2 This is a schematic diagram of the configuration of the blade assembly according to some embodiments of the present disclosure in a standard styling space;

[0027] Figure 3This is a schematic diagram of the configuration of the blade assembly according to some embodiments of the present disclosure in the XY plane coordinate system in standard shape space;

[0028] Figure 4 This is a schematic diagram of the configuration of some embodiments of the blade assembly according to the present disclosure in the XZ plane coordinate system in standard shape space;

[0029] Figure 5 This is a schematic diagram simulating airflow in the endwall region of a turbomachinery that does not employ the blade assembly disclosed herein.

[0030] Figure 6 This is a schematic diagram simulating airflow in the endwall region of a turbomachinery employing the blade assembly disclosed herein;

[0031] Figure 7 This is a schematic diagram simulating airflow loss in the endwall region of a turbomachinery that does not use the blade assembly disclosed herein.

[0032] Figure 8 This is a schematic diagram simulating airflow loss in the endwall region of a turbomachinery employing the blade assembly disclosed herein. Detailed Implementation

[0033] Various exemplary embodiments of the present disclosure will now be described in detail with reference to the accompanying drawings. The descriptions of the exemplary embodiments are merely illustrative and are in no way intended to limit the present disclosure or its application or use. The present disclosure may be implemented in many different forms and is not limited to the embodiments herein. These embodiments are provided so that the present disclosure will be thorough and complete, and will fully express the scope of the disclosure to those skilled in the art. It should be noted that, unless specifically stated otherwise, the relative arrangement of components and steps, the composition of materials, numerical expressions, and values ​​set forth in these embodiments should be interpreted as merely exemplary and not as limiting.

[0034] The terms "first," "second," and similar words used in this disclosure do not indicate any order, quantity, or importance, but are merely used to distinguish different parts. Words such as "including" or "contains" mean that the element preceding the word encompasses the element listed after it, and do not exclude the possibility of encompassing other elements as well. Terms such as "above," "below," "left," and "right" are used only to indicate relative positional relationships; when the absolute position of the described object changes, this relative positional relationship may also change accordingly.

[0035] In this disclosure, when a specific device is described as being located between a first device and a second device, an intermediary device may or may not be present between the specific device and the first or second device. When a specific device is described as being connected to other devices, the specific device may be directly connected to the other devices without an intermediary device, or it may be not directly connected to the other devices but have an intermediary device.

[0036] All terms used in this disclosure have the same meaning as understood by one of ordinary skill in the art to which this disclosure pertains, unless otherwise specifically defined. It should also be understood that terms defined in general dictionaries should be interpreted as having meanings consistent with their meanings in the context of the relevant art, and not as idealized or highly formalized, unless expressly defined herein.

[0037] Techniques, methods, and equipment known to those skilled in the art may not be discussed in detail, but where appropriate, they should be considered part of the specification.

[0038] Combination Figures 1-4 As shown, some embodiments of this disclosure provide a blade assembly, including: a blade 1 and an endwall member 10. The blade 1 is disposed on the endwall member 10, and a tangential channel 2 and a flow channel 3 are formed on the endwall surface of the endwall member 10. The endwall member 10 can be a hub or a casing. The tangential channel 2 is located at the leading edge of the blade 1, and the flow channel 3 is located on the suction side of the blade 1. The tangential channel 2 and the flow channel 3 connect to form a smooth L-shaped channel.

[0039] In this illustrative embodiment, by machining a smooth L-shaped channel on the endwall surface of the endwall component, the tangential channel 2 causes the near-endwall incoming flow to separate within it, forming a tangential separation vortex. The separation vortex, guided by the channel 3 within the L-shaped channel, is deflected in the opposite direction to the channel vortex formed by the secondary flow from the endwall. This directional vortex can prevent the channel vortex from reaching the adjacent blade suction surface-endwall corner region, suppressing the interaction between the endwall secondary flow and the blade surface boundary layer, thereby reducing end-region aerodynamic losses and improving turbomachinery efficiency. The endwall component 10 with the smooth geometric L-shaped channel can be manufactured using existing precision casting or CNC machining techniques without causing serious structural reliability problems such as stress concentration and high-temperature ablation, thus showing good application prospects in turbomachinery components of aero-gas turbine engines.

[0040] To improve aerodynamic efficiency, such as Figure 1 and Figure 2 As shown, in some embodiments, the tangential channel 2 extends along a direction tangential to the leading edge of the blade 1, and the flow channel 3 extends along the back line of the blade 1.

[0041] like Figures 2-4 As shown, in some embodiments, the cross-sections of both the tangential channel 2 and the flow channel 3 are configured as arcuate lines to achieve a smooth geometric surface. In some embodiments, in a standard shaping space, the longitudinal cross-sections of both the tangential channel 2 and the flow channel 3 are configured as piecewise curves with arcuate lines on both sides and a horizontal straight line in the middle.

[0042] It should be noted that, in this article, the standard modeling space refers to the state in which the end wall surface of the end wall component 10 is transformed into a plane, such as... Figure 2 As shown.

[0043] In some embodiments, the curved line is configured as a sine curve. This has proven to achieve better aerodynamic efficiency.

[0044] like Figures 2-4 As shown, in the standard shape space, the longitudinal section of the tangential channel 2 is a combination curve 001 composed of a sine curve and a horizontal straight line, and the transverse section is a sine curve 002; the longitudinal section of the channel flowing towards the channel 3 is a combination curve 003 composed of a sine curve and a horizontal straight line, and the cross section is a sine curve 004.

[0045] Some embodiments of this disclosure provide a design method for the aforementioned blade assembly, including:

[0046] The standard design space is set as follows: X, Y, and Z represent the radial, circumferential, and central arc lines of the impeller mechanical channel standard space, as well as their upstream and downstream extensions, respectively; Y=0 represents the central arc line of the blade and its upstream and downstream extensions, Y=1 represents the central arc line of adjacent blades and its upstream and downstream extensions; Z=0 and Z=1 represent the leading and trailing edge lines of the blade, Z<0 represents the upstream region of the blade, and Z>1 represents the downstream region of the blade.

[0047] The cylindrical coordinate system of the end wall region is defined as (r, θ, z). The actual surface coordinates of the end wall component 10 and the surface coordinates within the standard shaping range have the following transformation relationship:

[0048]

[0049] Where δ is the thickness of the incoming boundary layer, r endwall Here, θ is the radial coordinate of the endwall, N is the number of blades, and θ is the radial coordinate of the end camber Let c be the circumferential coordinates of the mid-arc line and its extension of the endwall airfoil. z Z is the axial chord length of the endwall airfoil. LE δ represents the axial coordinate of the leading edge of the blade. When the end wall component 10 is a hub, the sign before δ is “-”; when the end wall component 10 is a casing, the sign before δ is “+”.

[0050] Of course, coordinate transformation can also be achieved using a Cartesian coordinate system. Some embodiments of this disclosure provide a design method for the aforementioned blade assembly, including:

[0051] The standard design space is set as follows: X, Y, and Z represent the radial, circumferential, and central arc lines of the impeller mechanical channel standard space, as well as their upstream and downstream extensions, respectively; Y=0 represents the central arc line of the blade and its upstream and downstream extensions, Y=1 represents the central arc line of adjacent blades and its upstream and downstream extensions; Z=0 and Z=1 represent the leading and trailing edge lines of the blade, Z<0 represents the upstream region of the blade, and Z>1 represents the downstream region of the blade.

[0052] In the standard design space, the geometry of the L-shaped channel is determined by six dimensionless design parameters, including: the dimensionless width T1 of the tangential channel 2; the dimensionless length L1+T2 of the tangential channel 2; the dimensionless width T2 of the flow channel 3; the dimensionless length L2+T1 of the flow channel 3; the dimensionless distance D between the flow channel 3 and the mid-curve of the blade; and the maximum dimensionless depth H of the L-shaped channel. By appropriately selecting the values ​​of the above six parameters, the endwall configuration geometry in the standard orthogonal space can be obtained.

[0053] The Cartesian coordinate system of the end wall region is defined as x, y, z, where x represents the spanwise direction, y represents the tangential direction, and z represents the axial direction. The actual surface coordinates of the end wall component 10 and the surface coordinates within the standard shaping range have the following transformation relationship:

[0054]

[0055] Where δ is the thickness of the incoming boundary layer, x endwall Here are the radial coordinates of the endwall, s is the grid pitch, and y is the radial coordinate of the endwall. camber Let c be the tangential coordinate of the mid-arc line and its extension of the blade 1. z Let z be the axial chord length of the blade 1. LE δ represents the axial coordinate of the leading edge of the blade 1. When the end wall component 10 is a hub, the sign before δ is "-"; when the end wall component 10 is a casing, the sign before δ is "+".

[0056] Taking the compressor blade assembly as an example, with δ=4mm, x endwall =0mm, s=22mm, c z =36.96 mm, z LE =0mm.

[0057] In some embodiments, the dimensionless width T1 of the tangential channel 2 is 0.16; the dimensionless length L1+T2 of the tangential channel 2 is 0.53; the dimensionless width T2 of the flow channel 3 is 0.35; the dimensionless length L2+T1 of the flow channel 3 is 0.87; the dimensionless distance D between the flow channel 3 and the arc of the blade is 0.10; and the maximum dimensionless depth H of the L-shaped channel is 0.38.

[0058] Combination Figure 5 and Figure 6As shown in the comparison, the airflow moves to the suction surface of the adjacent blade 1 under the action of the lateral pressure difference in the channel, and is swirled up to form a large-sized channel vortex 4. However, when using the blade assembly disclosed in this invention, such as... Figure 6 As shown, the airflow separates at the leading edge tangential channel, inducing the generation of separation vortex 6′. Under the action of the channel, the separation vortex forms a robust flow vortex 5′. This flow vortex 5′ is opposite in direction to the channel vortex 4′, so as to prevent the channel vortex from reaching the suction surface of the adjacent blade cascade and control the interaction between the channel vortex and the boundary layer on the blade surface, thereby reducing losses and improving the mechanical efficiency of the impeller.

[0059] Combination Figure 7 and Figure 8 As shown in the comparison, it can be observed that Figure 8 A robust induced vortex 5′ forms within the channel, significantly suppressing the development of the channel vortex 4′. The peak value and spanwise range of the total pressure loss 7′ are significantly weaker than those of the channel vortex 4′. Figure 7 The total pressure loss is 7%, and the peak position is far from the suction surface of adjacent blades. This shows that the endwall configuration based on the vortex generator principle has a significant flow control effect.

[0060] Table 1 shows the control effect of this endwall configuration on the total pressure loss of the blade cascade under different operating conditions. Among them, the total pressure loss coefficient is reduced by 17.9% at the design angle of attack; and it can still significantly reduce the total pressure loss coefficient of the blade cascade under non-design operating conditions.

[0061] Table 1. Loss control characteristics based on vortex generator principle under different operating conditions.

[0062]

[0063] Some embodiments of this disclosure provide a gas turbine including the aforementioned blade assembly. The gas turbine accordingly possesses the aforementioned beneficial technical effects. In some embodiments, the gas turbine is an aircraft engine, and the blade assembly of this disclosure is applicable to, but is not limited to, the compressor and turbine of an aircraft gas turbine engine.

[0064] The embodiments of this disclosure have now been described in detail. To avoid obscuring the concept of this disclosure, some details known in the art have not been described. Those skilled in the art can fully understand how to implement the technical solutions disclosed herein based on the above description.

[0065] While specific embodiments of this disclosure have been described in detail by way of examples, those skilled in the art should understand that the examples are for illustrative purposes only and not intended to limit the scope of this disclosure. Those skilled in the art should understand that modifications can be made to the above embodiments or equivalent substitutions can be made to some technical features without departing from the scope and spirit of this disclosure. The scope of this disclosure is defined by the appended claims.

Claims

1. A blade assembly, characterized in that, include: Leaf (1); and The end wall component (10) has a tangential channel (2) and a flow channel (3) formed on its end wall surface; The blade (1) is disposed on the end wall member (10), the tangential channel (2) is located at the leading edge of the blade (1), the flow channel (3) is located on the suction side of the blade (1), the tangential channel (2) and the flow channel (3) are connected to form a smooth L-shaped channel, the tangential channel (2) extends along the direction tangential to the leading edge of the blade (1), and the flow channel (3) extends along the back line of the blade (1).

2. The blade assembly according to claim 1, characterized in that, The cross-sections of both the tangential channel (2) and the flow channel (3) are configured as arc lines.

3. The blade assembly according to claim 2, characterized in that, In the standard design space, the longitudinal sections of the tangential channel (2) and the flow channel (3) are both configured as segmented curves with arc lines on both sides and a horizontal straight line in the middle.

4. The blade assembly according to claim 2 or 3, characterized in that, The arc-shaped line is configured as a sine wave.

5. A design method for a blade assembly according to any one of claims 1 to 4, characterized in that, include: The standard design space is set as follows: X, Y, and Z represent the radial, circumferential, and central arc lines of the impeller mechanical channel standard space, as well as their upstream and downstream extensions, respectively; Y=0 represents the central arc line of the blade and its upstream and downstream extensions, Y=1 represents the central arc line of adjacent blades and its upstream and downstream extensions; Z=0 and Z=1 represent the leading and trailing edge lines of the blade, Z<0 represents the upstream region of the blade, and Z>1 represents the downstream region of the blade. The cylindrical coordinate system of the end wall region is set as (r, θ, z). The actual surface coordinates of the end wall component (10) and the surface coordinates within the standard shaping range have the following transformation relationship: Where δ is the thickness of the incoming boundary layer, r endwall Here, θ is the radial coordinate of the endwall, N is the number of blades, and θ is the radial coordinate of the endwall. camber Let c be the circumferential coordinates of the mid-arc line and its extension of the endwall airfoil. z Z is the axial chord length of the endwall airfoil. LE δ is the axial coordinate of the leading edge of the blade. When the end wall component (10) is a hub, the sign before δ is "-"; when the end wall component (10) is a casing, the sign before δ is "+".

6. A design method for a blade assembly according to any one of claims 1 to 4, characterized in that, include: The standard design space is set as follows: X, Y, and Z represent the radial, circumferential, and central arc lines of the impeller mechanical channel standard space, as well as their upstream and downstream extensions, respectively; Y=0 represents the central arc line of the blade and its upstream and downstream extensions, Y=1 represents the central arc line of adjacent blades and its upstream and downstream extensions; Z=0 and Z=1 represent the leading and trailing edge lines of the blade, Z<0 represents the upstream region of the blade, and Z>1 represents the downstream region of the blade. The rectangular coordinate system of the end wall region is set as (x, y, z), where x is the spanwise direction, y is the tangential direction, and z is the axial direction. The actual surface coordinates of the end wall component (10) have the following transformation relationship with the surface coordinates within the standard shaping range: Where δ is the thickness of the incoming boundary layer, x endwall Here are the radial coordinates of the endwall, s is the grid pitch, and y is the radial coordinate of the endwall. camber Let c be the tangential coordinate of the mid-arc line and its extension of the blade (1). z Let z be the axial chord length of the blade (1). LE Let be the axial coordinate of the leading edge of the blade (1).

7. The design method according to claim 6, characterized in that, The dimensionless width T1 of the tangential channel (2) is 0.16; the dimensionless length L1+T2 of the tangential channel (2) is 0.53; the dimensionless width T2 of the flow channel (3) is 0.35; the dimensionless length L2+T1 of the flow channel (3) is 0.87; the dimensionless distance D between the flow channel (3) and the arc of the blade is 0.10; and the maximum dimensionless depth H of the L-shaped channel is 0.

38.

8. A gas turbine, characterized in that, Includes the blade assembly as described in any one of claims 1 to 4.

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