Flow channel surface optimization design method, flow channel profile, adjustable guide vane design method and guide vane

Abstract

A flow channel surface optimization design method, flow channel profile, adjustable guide vane design method and guide vane, based on the initial flow channel surface, by cutting the adjustable guide vane blade at the design angle to obtain the coordinates of the leading edge point and the trailing edge point at the upper blade top or lower blade top position of the guide vane, then obtain the moving trajectory of the leading edge point and the trailing edge point during the adjustable guide vane angle adjustment process, based on the moving trajectory, obtain the flow channel contour of the adjustable guide vane; the flow channel contour at the above inlet position and the flow channel at the outlet position are connected after being trimmed and smoothed to form an optimized flow channel; based on the optimized flow channel, the adjustable guide vanes at different installation angles are cut to generate an optimized adjustable guide vane blade top profile and the guide vane itself. The adjustable guide vane and the corresponding flow channel with significantly reduced blade top radial clearance at the design angle obtained in the present disclosure effectively control the adjustable guide vane gap leakage, suppress the adjustable guide vane gap leakage flow and its influence on the three-dimensional flow field of the blade channel, and reduce the adjustable guide vane flow loss.

Description

Technical Field

[0001] The present invention belongs to the technical field of fluid power equipment, and specifically relates to a flow channel surface optimization design method, a flow channel profile, an adjustable guide vane design method, and a guide vane. Background Art

[0002] Adjustable guide vanes refer to guide vanes whose installation angle can be adjusted by rotating around their own rotation axis. When designing the top profile of the adjustable guide vanes, it is necessary to ensure that there is a certain tip clearance at each angle within the angle adjustment range.

[0003] The commonly used method for generating the top profile of the adjustable guide vane is to select several angle states within the adjustable guide vane angle adjustment range, and cut the top of the adjustable guide vane through the cutting surface formed by the conventionally designed flow channel surface offset to the inside of the flow channel. For the upper blade top of the adjustable guide vane, as the guide vane angle is closed more, the amount of cutting of the guide vane will be greater. At this time, when the adjustable guide vane returns to the design angle, a large radial clearance of the upper blade top will appear, especially when the closing angle of the adjustable guide vane at the inlet of the high-pressure ratio multi-stage compressor reaches 60°, a radial clearance of about 3.0 mm is usually formed on the inlet and outlet edges of the upper blade top of the adjustable guide vane, which is much larger than the radial clearance of 0.2 to 0.5 mm of other blade rows. As a result, the leakage of the upper blade top clearance of the guide vane increases significantly, resulting in an increase in the flow loss of the guide vane, affecting the performance of the whole machine. Summary of the invention

[0004] In order to solve the above-mentioned technical problems, the purpose of the present disclosure is to provide a flow path surface optimization design method, a flow path profile, an adjustable guide vane design method and a guide vane, which can reduce the tip clearance of an adjustable guide vane, achieve effective control of the tip clearance leakage, and thus reduce the flow loss of the adjustable guide vane.

[0005] In order to achieve the purpose of this disclosure, the technical solutions adopted by this disclosure are as follows:

[0006] A flow path surface optimization design method, wherein the flow path surface is used to match the tip profile of an adjustable guide vane, comprises the following steps:

[0007] Based on the adjustable guide vane blade at the initial flow path surface cutting design angle, obtaining the coordinates of the leading edge point and the trailing edge point of the upper blade tip of the adjustable guide vane, or obtaining the coordinates of the leading edge point and the trailing edge point of the lower blade tip of the adjustable guide vane;

[0008] According to the angle adjustment range of the adjustable guide vane, gradually adjusting the installation angle of the adjustable guide vane from an initial position to a maximum adjustment angle position, and obtaining a moving trajectory of the leading edge point and a moving trajectory of the trailing edge point during the adjustment of the adjustable guide vane angle;

[0009] Based on the moving trajectory of the leading edge point, a flow passage profile at an inlet position of the adjustable guide vane is obtained; based on the moving trajectory of the trailing edge point, a flow passage profile at an outlet position of the adjustable guide vane is obtained;

[0010] The flow channel profile at the inlet position of the adjustable guide vane is smoothly connected with the flow channel at the outlet position of the adjustable guide vane to form an optimized flow channel surface corresponding to the adjustable guide vane.

[0011] Optionally, when the leading edge point and the trailing edge point are at the upper blade tip position of the adjustable guide vane, the initial flow path surface and the optimized flow path surface are both surfaces on the casing that cooperate with the adjustable guide vane;

[0012] When the leading edge point and the trailing edge point are at the lower blade tip position of the adjustable guide vane, the initial flow path surface and the optimized flow path surface are both surfaces on the hub that cooperate with the adjustable guide vane.

[0013] Optionally, obtaining the flow channel profile at the inlet position of the adjustable guide vane based on the movement trajectory of the leading edge point includes:

[0014] Convert the moving trajectory of the leading edge point into an XR coordinate system as a flow channel profile at an inlet position of the adjustable guide vane;

[0015] The step of obtaining the flow channel profile at the outlet position of the adjustable guide vane based on the moving trajectory of the trailing edge point comprises:

[0016] Convert the moving trajectory of the trailing edge point into an XR coordinate system as a flow channel profile at an outlet position of the adjustable guide vane;

[0017] The flow channel profile at the inlet position and the flow channel profile at the outlet position both include flow channel axis coordinates and a flow channel radius.

[0018] Optionally, the step of smoothly connecting the flow channel profile at the inlet position of the adjustable guide vane with the flow channel at the outlet position of the adjustable guide vane to form an optimized flow channel surface corresponding to the adjustable guide vane includes:

[0019] The flow path line formed by smoothly connecting the flow path contour at the inlet position of the adjustable guide vane and the flow path at the outlet position of the adjustable guide vane is used as the initial flow path line;

[0020] The initial flow channel line is offset toward the flow channel inner cavity direction of the casing, and the offset flow channel line is used as the final flow channel line;

[0021] The final flow path line is rotated to form an optimized flow path surface corresponding to the adjustable guide vane.

[0022] Optionally, the final flow channel surface radius is determined according to the following formula:

[0023] r=r0+δ·(r r -r0)

[0024] Where r is the radius of the final flow channel surface at a certain axial position, r0 is the radius of the initial flow channel surface at the same axial position, δ is the flow channel deviation coefficient, ranging from 0 to 1, r r It is the radius corresponding to the moving trajectory line of the leading edge point or the trailing edge point at the same axial position.

[0025] The present disclosure also provides a flow channel profile, which is arranged on the inner wall of the casing or the outer wall of the hub and is used to cooperate with the adjustable guide vane. The shape of the flow channel profile is obtained by the above-mentioned flow channel surface optimization design method.

[0026] The present disclosure also provides an adjustable guide vane design method for designing an adjustable guide vane tip profile that matches the above-mentioned flow channel profile, the design method comprising:

[0027] Based on the optimized flow channel surface corresponding to the adjustable guide vane, a cutting surface is formed after being offset toward the inside of the flow channel.

[0028] The adjustable guide vane is cut based on the cutting surface to obtain the profile of the upper blade tip and / or the lower blade tip of the adjustable guide vane.

[0029] Optionally, the cutting of the adjustable guide vane based on the cutting surface to obtain the profile of the upper blade tip and / or the lower blade tip of the adjustable guide vane includes:

[0030] The adjustable guide vane is adjusted from an initial position to a maximum angle position at preset angle intervals. After each adjustment, the adjustable guide vane is cut based on the cutting surface to finally obtain the profile of the upper blade tip and / or lower blade tip of the adjustable guide vane.

[0031] Optionally, the preset angle interval is 3 to 5°.

[0032] An adjustable guide vane comprises an adjustable guide vane body, wherein the adjustable guide vane body is provided with an upper blade top and a lower blade top, and the profiles of the upper blade top and the lower blade top are obtained by the above-mentioned adjustable guide vane design method.

[0033] The present invention is based on the movement trajectory of the leading edge point and the trailing edge point of the initial blade profile during the adjustable guide vane angle adjustment process, and obtains the flow channel profile at the inlet position and the outlet position based on the movement trajectory, thereby obtaining the final optimized flow channel surface. The present invention makes the new flow channel surface more compatible with the coordinate change of the blade tip profile when the adjustable guide vane angle is adjusted, and reduces the blade tip clearance of the guide vane at the designed installation angle. Finally, an adjustable guide vane and its corresponding flow channel with significantly reduced blade tip radial clearance at the designed angle state are obtained, which effectively controls the leakage of the adjustable guide vane tip clearance, suppresses the leakage flow of the adjustable guide vane tip clearance and its influence on the three-dimensional flow field of the blade channel, and reduces the flow loss of the adjustable guide vane. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] The accompanying drawings illustrate exemplary embodiments of the present disclosure and together with the description serve to explain the principles of the present disclosure. These drawings are included to provide a further understanding of the present disclosure and are incorporated in and constitute a part of this specification.

[0035] Figure 1 It is a structural schematic diagram of the adjustable guide vane and the corresponding flow channel in the present disclosure;

[0036] Figure 2 It is a schematic diagram of the geometric relationship between the adjustable guide vane installation angle and the corresponding flow channel after the change in the present disclosure.

[0037] Figure 3 It is a structural schematic diagram of the adjustable guide vanes in the designed angle state and the corresponding flow channels during the implementation of the present disclosure.

[0038] Figure 4 This is a schematic diagram of the flow channel surface optimization design method disclosed in the present invention.

[0039] Figure 5 It is a schematic diagram of the structure of the casing disclosed in the present invention.

[0040] Figure 6 It is a schematic diagram of the structure of the adjustable guide vane disclosed in the present invention.

[0041] Figure 7 The figure is a comparison diagram of the upper blade tip clearance when the adjustable guide vane with an angle adjustment range of -60° to 0° is at the designed angle position using the method disclosed in the present invention and the method using the prior art.

[0042] Figure 8 This is a comparison diagram of the upper blade tip clearance when the adjustable guide vane with an angle adjustment range of -60° to 0° is at the -60° position using the method disclosed in the present invention and the method using the prior art.

[0043] Fig. 9 The figure is a comparison diagram of the total pressure recovery coefficient when the adjustable guide vane with an angle adjustment range of -60° to 0° is at the designed angle position using the method disclosed in the present invention and the method using the prior art.

[0044] Fig.10 This is a comparison diagram of the upper blade tip clearance when the adjustable guide vane is at the designed angle position within the angle adjustment range of -20° to 0° using the method disclosed in the present invention and using the prior art method.

[0045] Fig.11 This is a comparison diagram of the upper blade tip clearance when the adjustable guide vane with an angle adjustment range of -20° to 0° is at the -18° position using the method disclosed in the present invention and the method using the prior art.

[0046] Fig.12The present invention provides a comparison chart of the total pressure recovery coefficient when the adjustable guide vane with an angle adjustment range of -20° to 0° is at the designed angle position by using the method disclosed in the present invention and the method of the prior art. DETAILED DESCRIPTION

[0047] The present disclosure is further described in detail below in conjunction with the accompanying drawings and implementations. It is understood that the specific implementations described herein are only used to explain the relevant content, rather than to limit the present disclosure. It should also be noted that, for ease of description, only the parts related to the present disclosure are shown in the accompanying drawings.

[0048] It should be noted that, in the absence of conflict, the embodiments and features of the embodiments in the present disclosure may be combined with each other. The present disclosure will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0049] See also Figure 1 , Figure 2 , Figure 3 As shown, some embodiments of the present disclosure provide a flow path surface optimization design method, which is applicable to impellers such as compressors, fans and fans with adjustable guide vanes, wherein the casing 1 is used to install the adjustable guide vanes 2, the casing flow channel 11 corresponding to the casing 1 and the hub flow channel 31 corresponding to the hub 3 form an air flow channel, the adjustable guide vane 2 is arranged between the hub 3 and the casing 1, the gap between the upper blade top 21 of the adjustable guide vane 2 and the casing 1 forms an upper blade top gap 41, and the gap between the lower blade top 22 of the adjustable guide vane 2 and the hub 3 forms a lower blade top gap 42, in the present disclosure, the casing flow channel 11 and the hub flow channel 31 are used to cooperate with the adjustable guide vane 2; and a rotating shaft 5 is also provided on the adjustable guide vane 2, and the adjustable guide vane 2 can deflect around the rotating shaft 5 to adjust the installation angle of the adjustable guide vane 2.

[0050] See also Figure 4 As shown, the flow channel surface optimization design method includes the following steps:

[0051] S10, based on the initial flow channel surface, obtaining the coordinates of the leading edge point A1 and the trailing edge point B1 at the upper blade tip 21 of the adjustable guide vane, or obtaining the coordinates of the leading edge point A2 and the trailing edge point B2 at the lower blade tip 22 of the adjustable guide vane;

[0052] When the adjustable guide vane 2 is adjusted in angle around the rotating shaft 5, the movement trajectory of the upper blade top leading edge point A1 and the trailing edge point B1 is used to determine the optimized flow path surface of the casing at the inlet position and the outlet position of the adjustable guide vane; the movement trajectory of the lower blade top leading edge point A2 and the trailing edge point B2 is used to determine the optimized flow path surface of the hub at the inlet position and the outlet position of the adjustable guide vane.

[0053] The embodiments of the present disclosure are described by taking the generation of the optimized flow path surface of the casing of the adjustable guide vane as an example, and the generation principle of the optimized flow path surface of the hub is the same.

[0054] The method for obtaining the coordinates of the leading edge point and the trailing edge point is to cut the adjustable guide vane 2 under the design installation angle using the initial flow passage surface of the casing 1 to form an initial upper blade top profile, thereby obtaining the coordinates of the leading edge point and the trailing edge point of the adjustable guide vane on the profile;

[0055] S20, gradually adjusting the angle of the adjustable guide vane 2 from the initial position to the maximum adjustment angle position according to the angle adjustment range of the adjustable guide vane,

[0056] According to the working characteristics of the impeller, the closing angle range required for the adjustable guide vane is often much wider than the opening angle range. For example, the angle adjustment range of the adjustable guide vane at the inlet of a high-pressure ratio multi-stage compressor is usually (-60°~+10°), at which time the angle of the adjustable guide vane ranges from the initial position (0°) to the maximum adjustment angle position (-60°). The angle adjustment range of the first-stage adjustable guide vane is usually (-25°~+5°), and the angle of the adjustable guide vane ranges from the initial position (0°) to the maximum adjustment angle position (-25°).

[0057] Obtain the moving trajectory of the leading edge point A1 and the moving trajectory of the trailing edge point B1 during the adjustable guide vane angle adjustment process; the coordinates of the leading edge point A1 in the present disclosure are (x0, y0, z0),

[0058] The moving trajectory of the leading edge point A1 (x L ,y L ,z L )The parameter equation for adjusting the angle θ is:

[0059]

[0060] The calculation method of the movement trajectory of the trailing edge point B1 is the same as that of the movement trajectory of the leading edge point A1.

[0061] S30, obtaining a flow passage profile at an inlet position of the adjustable guide vane 2 based on the moving trajectory of the leading edge point A1; and obtaining a flow passage profile at an outlet position of the adjustable guide vane based on the moving trajectory of the trailing edge point B1.

[0062] The moving trajectory of the leading edge point is converted to the XR coordinate system as the flow path profile at the inlet position of the adjustable guide vane; the moving trajectory of the trailing edge point is converted to the XR coordinate system as the flow path profile at the outlet position of the adjustable guide vane; the flow path profile can be obtained by the flow path axis coordinate x r and flow channel radius r r To identify.

[0063] This embodiment takes the flow passage profile at the inlet position of the adjustable guide vane 2 as an example based on the moving trajectory of the leading edge point A1;

[0064] Convert the three-dimensional moving trajectory of the leading edge point A1 into the XR coordinate system to obtain the coordinates of the new flow channel inlet section:

[0065]

[0066] Based on the moving trajectory of the trailing edge point B1, the flow channel profile at the outlet position of the adjustable guide vane can also be converted based on the above formula.

[0067] Since then, the flow channel profile at the inlet position and the flow channel profile at the outlet position of the adjustable guide vane have been determined, and the flow channel line between the inlet position and the outlet position of the adjustable guide vane is still missing.

[0068] S40, comprehensively considering the smooth connection between the flow channel inlet and outlet positions and the upstream and downstream flow channels and other design requirements, smoothly connect the flow channel profile at the inlet position of the adjustable guide vane 2 with the flow channel at the outlet position of the adjustable guide vane 2 to form an optimized flow channel surface at the position of the adjustable guide vane 2. Specifically including:

[0069] The flow channel contour at the inlet position of the adjustable guide vane and the flow channel at the outlet position of the adjustable guide vane are smoothed and connected to form an optimized adjustable guide vane flow channel;

[0070] The optimized flow path line is rotated to form an optimized flow path surface corresponding to the adjustable guide vane.

[0071] The advantages of using a rotary flow channel are: 1. The flow channel surface is smooth, which can avoid flow losses caused by low-speed fluid aggregation; 2. The processing technology is good, and conventional flow channel surface processing methods can be directly adopted; 3. There is no need to deliberately increase the thickness of the casing wall, which has obvious weight reduction advantages for aircraft engines.

[0072] In a preferred embodiment, the final flow channel surface modification design is determined according to the following formula:

[0073] r=r0+δ·(r r -r0)

[0074] Where r is the radius of the final flow channel surface at a certain axial position, r0 is the radius of the initial flow channel surface at the same axial position, δ is the flow channel deviation coefficient, ranging from 0 to 1, r r It is the radius corresponding to the moving trajectory line of the leading edge point or the trailing edge point at the same axial position.

[0075] The new flow channel designed according to δ=1.0 can ensure that the flow channel surface will not cut the adjustable guide vane when the guide vane angle is closed, and the upper blade tip clearance of the corresponding leading and trailing edge points at the designed installation angle is the smallest, but it will cause a large degree of unevenness in the corresponding flow channel of the adjustable guide vane, and may also cause problems in the casing structure design; the new flow channel designed according to δ=0 is a conventional flow channel.

[0076] In one embodiment, the casing flow passage profiles at the corresponding positions of the inlet section and the outlet section of the adjustable guide vane can be obtained based on the movement trajectories of the leading edge point A1 and the trailing edge point B1 at the upper blade top 21 of the adjustable guide vane; and the hub flow passage profiles at the corresponding positions of the inlet section and the outlet section of the adjustable guide vane can be obtained based on the movement trajectories of the leading edge point A2 and the trailing edge point B2 at the lower blade top 22 of the adjustable guide vane.

[0077] See also Figure 5 As shown, the present disclosure also provides a flow channel profile corresponding to an adjustable guide vane, which is arranged on the inner wall of the casing to form a casing flow channel 11, or is arranged on the outer wall of the hub to form a hub flow channel 12, and the shape of the flow channel profile is obtained by the above-mentioned flow channel surface optimization design method of the adjustable guide vane. The gap between the flow channel and the upper blade tip 21 of the adjustable guide vane disclosed in the present disclosure is small, which effectively controls the leakage of the upper blade tip gap of the adjustable guide vane, suppresses the leakage flow of the upper blade tip gap of the adjustable guide vane and its influence on the three-dimensional flow field of the blade channel, and reduces the flow loss of the adjustable guide vane.

[0078] The present disclosure also provides an adjustable guide vane design method for designing an adjustable guide vane that matches the above-mentioned flow channel profile, the design method comprising:

[0079] Based on the optimized flow channel surface corresponding to the adjustable guide vane, a cutting surface is formed after being offset inside the flow channel, and the control of the blade tip clearance and the prevention of interference between the blade tip and the flow channel surface during the adjustment of the adjustable guide vane angle are taken into account. The flow channel offset can be taken as 0.2mm to 0.3mm.

[0080] The adjustable guide vane is cut based on the cutting surface to obtain the profile of the upper blade tip 21 and / or the lower blade tip 22 of the adjustable guide vane 2 .

[0081] By means of the above method, the cutting profile at the position of the upper blade tip 21 and / or the lower blade tip 22 of the adjustable guide vane can be obtained.

[0082] The guide vane designed by the design method of the adjustable guide vane 2 disclosed in the present embodiment can be matched with the casing 1 in the present disclosure to obtain an adjustable guide vane 2 with a smaller gap between the upper blade top 21 or the lower blade top, which can effectively control the leakage of the blade tip gap of the adjustable guide vane 2, inhibit the leakage flow of the blade tip gap of the adjustable guide vane 2 and its influence on the three-dimensional flow field of the blade channel, and reduce the flow loss of the adjustable guide vane 2.

[0083] In another embodiment, the cutting of the upper blade tip 21 and / or the lower blade tip 22 of the adjustable guide vane 2 based on the cutting surface to obtain the profile of the upper blade tip 21 and / or the lower blade tip 22 of the adjustable guide vane 2 includes:

[0084] The adjustable guide vane 2 is adjusted from the initial position to the maximum angle position at preset angle intervals. After each adjustment, the upper blade top 21 and / or the lower blade top 22 of the adjustable guide vane 2 are cut based on the cutting surface, and the profile of the upper blade top 21 and / or the lower blade top 22 of the adjustable guide vane 2 is finally obtained. Since the cutting surface is formed by the flow channel surface being offset toward the inside of the flow channel, the adjustable guide vane blade top profile formed after cutting at multiple angles will not interfere with the corresponding flow channel surface at any angle. The preset angle interval can be set to 3 to 5°, or it can be set to other angles as needed.

[0085] See also Figure 6 As shown, the present disclosure also provides an adjustable guide vane, including an adjustable guide vane body, wherein the adjustable guide vane body has an upper blade top 21 and a lower blade top 22, and the shapes of the upper blade top 21 and the lower blade top 22 are obtained by the above-mentioned adjustable guide vane design method.

[0086] See also Figure 7 , Figure 8 As shown, after the design method of the present disclosure is used for the adjustable guide vane with an angle adjustment range of (-60°~0°), compared with the conventional design: at the design angle, the design of the present disclosure reduces the radial clearance of the blade tip 21 at the leading edge point of the adjustable guide vane from 2.36mm to 1.30mm, a relative reduction of 45%; the radial clearance of the blade tip 21 at the trailing edge point is reduced from 2.2mm to 1.08mm, a relative reduction of 51%. At the same time, at a closed angle of 60°, except for a slight increase in the clearance near the outlet area, the rest is consistent with the conventional design.

[0087] In addition, simulation analysis was performed on the improvement of the flow loss in the guide vane clearance of the adjustable guide vane with an angle adjustment range of (-60°~0°);

[0088] See also Fig. 9 As shown, the three-dimensional numerical simulation results show that after adopting the disclosed method, when the adjustable guide vane is at the design angle state, the leakage flow of the upper blade tip clearance is reduced by 15.6%, and in the entire stable working range, the total pressure loss coefficient of the adjustable guide vane is improved.

[0089] See also Fig.10 , Fig.11 As shown, after the design method disclosed in the present invention is used for the adjustable guide vane with an angle adjustment range of (-20°~0°), compared with the conventional design: at the design angle, the design disclosed in the present invention reduces the radial clearance of the blade tip 21 at the leading edge point of the adjustable guide vane from 1.52mm to 0.66mm, a relative reduction of 56.6%; the radial clearance of the blade tip 21 at the trailing edge point is reduced from 0.8mm to 0.25mm, a relative reduction of 68.8%. At the same time, at a reduced angle of 18°, the upper blade tip clearance is also reduced by 0.1mm~0.2mm.

[0090] In addition, simulation analysis was performed on the improvement of the flow loss in the guide vane clearance of the adjustable guide vane with an angle adjustment range of (-20°~0°);

[0091] See also Fig.12 As shown, the three-dimensional numerical simulation results show that after adopting the disclosed method, when the adjustable guide vane is at the design angle state, the leakage flow of the upper blade tip clearance is reduced by 34.1%, and in the entire stable working range, the total pressure loss coefficient of the adjustable guide vane is improved.

[0092] In the description of this specification, the description with reference to the terms "one embodiment / method", "some embodiments / methods", "example", "specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment / method or example are included in at least one embodiment / method or example of the present application. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment / method or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments / methods or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments / methods or examples described in this specification and the features of the different embodiments / methods or examples, unless they are contradictory.

[0093] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In the description of this application, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0094] Those skilled in the art should understand that the above embodiments are only for the purpose of clearly illustrating the present disclosure, and are not intended to limit the scope of the present disclosure. For those skilled in the art, other changes or modifications may be made based on the above disclosure, and these changes or modifications are still within the scope of the present disclosure.

Claims

1. A flow path surface optimization design method, the flow path surface is used to match the tip profile of an adjustable guide vane, characterized in that: The following steps are involved: Based on the adjustable guide vane blade at the initial flow path surface cutting design angle, obtaining the coordinates of the leading edge point and the trailing edge point of the upper blade tip of the adjustable guide vane, or obtaining the coordinates of the leading edge point and the trailing edge point of the lower blade tip of the adjustable guide vane; According to the angle adjustment range of the adjustable guide vane, gradually adjusting the installation angle of the adjustable guide vane from an initial position to a maximum adjustment angle position, and obtaining a moving trajectory of the leading edge point and a moving trajectory of the trailing edge point during the adjustment of the adjustable guide vane angle; Based on the moving trajectory of the leading edge point, a flow passage profile at an inlet position of the adjustable guide vane is obtained; based on the moving trajectory of the trailing edge point, a flow passage profile at an outlet position of the adjustable guide vane is obtained; The flow channel profile at the inlet position of the adjustable guide vane is smoothly connected with the flow channel at the outlet position of the adjustable guide vane to form an optimized flow channel surface corresponding to the adjustable guide vane.

2. The flow channel surface optimization design method according to claim 1, characterized in that: When the leading edge point and the trailing edge point are at the upper blade tip position of the adjustable guide vane, the initial flow path surface and the optimized flow path surface are both surfaces on the casing that cooperate with the adjustable guide vane; When the leading edge point and the trailing edge point are at the lower blade tip position of the adjustable guide vane, the initial flow path surface and the optimized flow path surface are both surfaces on the hub that cooperate with the adjustable guide vane.

3. The flow channel surface optimization design method according to claim 1, characterized in that: The step of obtaining the flow passage profile at the inlet position of the adjustable guide vane based on the moving trajectory of the leading edge point comprises: Convert the moving trajectory of the leading edge point into an XR coordinate system as a flow channel profile at an inlet position of the adjustable guide vane; The step of obtaining the flow channel profile at the outlet position of the adjustable guide vane based on the moving trajectory of the trailing edge point comprises: Convert the moving trajectory of the trailing edge point into an XR coordinate system as a flow channel profile at an outlet position of the adjustable guide vane; The flow channel profile at the inlet position and the flow channel profile at the outlet position both include flow channel axis coordinates and a flow channel radius.

4. The flow channel surface optimization design method according to claim 3, characterized in that: The step of smoothly connecting the flow channel profile at the inlet position of the adjustable guide vane with the flow channel at the outlet position of the adjustable guide vane to form an optimized flow channel surface corresponding to the adjustable guide vane comprises: The flow path line formed by smoothly connecting the flow path contour at the inlet position of the adjustable guide vane and the flow path at the outlet position of the adjustable guide vane is used as the initial flow path line; The initial flow channel line is offset toward the flow channel inner cavity direction of the casing, and the offset flow channel line is used as the final flow channel line; The final flow path line is rotated to form an optimized flow path surface corresponding to the adjustable guide vane.

5. The flow channel surface optimization design method according to claim 4, characterized in that: The final flow path surface radius is determined according to the following formula: r=r0+δ·(r r -r0) Where r is the radius of the final flow channel surface at a certain axial position, r0 is the radius of the initial flow channel surface at the same axial position, δ is the flow channel deviation coefficient, ranging from 0 to 1, r r It is the radius corresponding to the moving trajectory line of the leading edge point or the trailing edge point at the same axial position.

6. A flow channel profile, arranged on the inner wall of the casing or the outer wall of the hub, for cooperating with an adjustable guide vane, characterized in that: The shape of the flow channel profile is obtained by the flow channel surface optimization design method described in any one of claims 1-5.

7. A method for designing an adjustable guide vane, characterized in that: A method for designing an adjustable guide vane tip profile that matches the flow channel profile of claim 6 includes: Based on the optimized flow channel surface corresponding to the adjustable guide vane, a cutting surface is formed after being offset toward the inside of the flow channel. The adjustable guide vane is cut based on the cutting surface to obtain the profile of the upper blade tip and / or the lower blade tip of the adjustable guide vane.

8. The adjustable guide vane design method according to claim 7, characterized in that: The method of cutting the adjustable guide vane based on the cutting surface to obtain the profile of the upper blade tip and / or the lower blade tip of the adjustable guide vane includes: The adjustable guide vane is adjusted from an initial position to a maximum angle position at preset angle intervals. After each adjustment, the adjustable guide vane is cut based on the cutting surface to finally obtain the profile of the upper blade tip and / or lower blade tip of the adjustable guide vane.

9. The adjustable guide vane design method according to claim 8, characterized in that: The preset angle interval is 3 to 5 degrees.

10. An adjustable guide vane, characterized in that: It comprises an adjustable guide vane body, wherein the adjustable guide vane body has an upper blade top and a lower blade top, and the profiles of the upper blade top and the lower blade top are obtained by the adjustable guide vane design method according to any one of claims 7-9.

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