Fan last-stage stator and intermediate case support plate design method

Abstract

The invention provides a method for designing a fan last-stage stator and an intermediate case support plate, belongs to the technical field of compression systems in aero-engines, and particularly comprises the following steps: modeling the fan last-stage stator and the intermediate case support plate according to an integrated blade structure; the modeling method comprises the steps that the number and distribution of spanwise element blade profiles of the integrated blade structure are determined; the inlet geometric angle, the maximum thickness and the maximum thickness position of each primitive blade profile are determined; adjusting chord lengths of element blade profiles at different spanwise positions according to the three-dimensional modeling sweep quantity of the last-stage stator of the fan; according to the bending amount of the three-dimensional modeling of the fan last-stage stator, the bending angle distribution form of the element blade-shaped stator sections at different spanwise positions is adjusted; and carrying out trailing edge radial stacking on each element blade profile to obtain an integrated blade structure. On the premise that the requirement of the supporting plate structure is met, the influence of the supporting plate potential effect on the upstream stator is reduced, and the stator-supporting plate integrated ultra-compact intermediate case design is achieved.

Description

Technical Field

[0001] This application relates to the field of compression systems in aero engines, and more particularly to a design method for a fan final stage stator and intermediate casing support plate. Background Technology

[0002] like Figure 1 As shown, in order to shorten the axial dimension of the aero-engine and thus reduce its weight and increase its thrust-to-weight ratio, researchers reduced the degree of deflection of the intermediate casing flow channel by increasing the downward pressure of the stator 1 of the upstream fan final stage, thereby shortening the axial length of the intermediate casing, that is, realizing a compact intermediate casing design with the stator 1 coupled to the support plate 2.

[0003] However, with the further shortening of the axial length of the intermediate casing, the distance between the fan's final stage stator and the internal support plate of the intermediate casing is further compressed. The support plate's potential effect will adversely affect the aerodynamic performance of the upstream stator, thus increasing the design difficulty of the stator. On the other hand, as an indispensable structural component in the intermediate casing, the support plate provides additional support for the bearings and also provides a path for the cooling air and lubricating oil required by the engine. This often limits the design of the support plate's aerodynamic shape due to structural requirements, making it difficult to eliminate the support plate's potential effect at its root. Both of these factors restrict the engineering application of ultra-compact intermediate casings. Therefore, there is an urgent need for a design method that meets the structural requirements of the support plate while reducing the impact of the support plate's potential effect on the upstream stator. Summary of the Invention

[0004] In view of this, this application provides a design method for the fan final stage stator and intermediate casing support plate, which solves the problems in the prior art. Under the premise of meeting the support plate structure requirements, it can reduce the impact of the support plate potential on the upstream stator and realize an ultra-compact intermediate casing design integrating the stator and support plate.

[0005] The design method for a fan final stage stator and intermediate casing support plate provided in this application adopts the following technical solution: A design method for a fan final stage stator and intermediate casing support plate, wherein the fan final stage stator and intermediate casing support plate are shaped as an integrated blade structure, the integrated blade structure including a stator section and a support plate section. The styling method includes the following steps: Determine the number and distribution of spanwise blade elements in the integrated blade structure; The inlet geometry, maximum thickness, and maximum thickness position of each basic airfoil are determined based on the stator inlet geometry, the maximum thickness of the support plate, the position of the maximum thickness of the support plate, and the relative position of the support plate's trailing edge. Adjust the chord length of the basic blade profiles at different spanwise positions based on the sweep of the three-dimensional shape of the fan's final stage stator; According to the bending amount of the three-dimensional modeling of the fan last-stage stator, the bending angle distribution form of the elementary blade profile stator section at different spanwise positions is adjusted. The elementary blade profiles are radially stacked to obtain the integrated blade structure.

[0006] Optionally, the specific steps of adjusting the bending angle distribution form of the elementary blade profile stator section at different spanwise positions according to the bending amount of the three-dimensional modeling of the fan last-stage stator comprise: The middle camber line of the elementary blade profile is divided into a stator middle camber line section and a strut middle camber line section; The bending angle distribution of the strut middle camber line section is kept unchanged; The junction point of the stator middle camber line section and the strut middle camber line section and the bending angle distribution of the stator middle camber line section are adjusted.

[0007] Optionally, at the same spanwise position and along the axial direction of the engine, the distance between the maximum thickness position of the elementary blade profile of the integrated blade structure and the trailing edge of the elementary blade profile is equal to the distance between the maximum thickness position of the intermediate casing strut and the trailing edge of the intermediate casing strut.

[0008] Optionally, at the same spanwise position, the maximum thickness value of the elementary blade profile of the integrated blade structure is equal to the maximum thickness value of the intermediate casing strut.

[0009] Optionally, the trailing edges of the elementary blade profiles are aligned during the process of radially stacking the elementary blade profiles.

[0010] Optionally, the stator section and the strut section of the integrated blade structure are smoothly transitioned.

[0011] In summary, the present application includes the following beneficial technical effects: The present application adopts a two-section middle camber line and thickness distribution blade profile modeling method and a three-dimensional stacking method matched with engineering requirements, has high degrees of freedom, can meet the structural strength requirements of the intermediate casing strut, can retain the original fan last-stage stator aerodynamic modeling, realizes the super-compact intermediate casing design of the stator-strut integration, and has a simple process, and only one modeling is needed to obtain the final geometry. BRIEF DESCRIPTION OF DRAWINGS

[0012] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings needed in the embodiments will be briefly introduced as follows. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor.

[0013] Figure 1 The structure schematic diagram of the fan last-stage stator and the intermediate casing strut in the prior art; Figure 2A flowchart illustrating the design method for the fan's final stage stator and intermediate casing support plate; Figure 3 This is a schematic diagram of the basic blade shape of the integrated blade structure in this application; Figure 4 This is a schematic diagram of the integrated blade structure in this application.

[0014] Explanation of reference numerals in the attached diagram: 1. Stator; 2. Support plate; 3. Stator segment; 4. Support plate segment. Detailed Implementation

[0015] The embodiments of this application will now be described in detail with reference to the accompanying drawings.

[0016] The following specific examples illustrate the implementation of this application. Those skilled in the art can easily understand other advantages and effects of this application from the content disclosed in this specification. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them. This application can also be implemented or applied through other different specific embodiments, and the details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of this application. It should be noted that, in the absence of conflict, the following embodiments and features in the embodiments can be combined with each other. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0017] It should be noted that various aspects of embodiments within the scope of the appended claims are described below. It will be apparent that the aspects described herein can be embodied in a wide variety of forms, and any particular structure and / or function described herein is merely illustrative. Based on this application, those skilled in the art will understand that one aspect described herein can be implemented independently of any other aspect, and two or more of these aspects can be combined in various ways. For example, any number of aspects set forth herein can be used to implement the device and / or practice the method. Additionally, this device and / or method can be implemented using structures and / or functionalities other than one or more of the aspects set forth herein.

[0018] It should also be noted that the illustrations provided in the following embodiments are only schematic representations of the basic concept of this application. The illustrations only show the components related to this application and are not drawn according to the number, shape and size of the components in actual implementation. In actual implementation, the form, quantity and proportion of each component can be arbitrarily changed, and the layout of the components may also be more complex.

[0019] Furthermore, specific details are provided in the following description to facilitate a thorough understanding of the examples. However, those skilled in the art will understand that the described aspects can be practiced without these specific details.

[0020] This application provides a design method for a fan final stage stator and an intermediate casing support plate.

[0021] like Figures 2 to 4 As shown, a design method for a fan final stage stator and intermediate casing support plate is proposed, in which the fan final stage stator and intermediate casing support plate are shaped as an integrated blade structure. The integrated blade structure includes a stator section 3 and a support plate section 4, and the stator section and support plate section of the integrated blade structure are smoothly transitioned.

[0022] The styling method includes the following steps: Determine the number and distribution of the spanwise basic element airfoils of the integrated blade structure; set multiple two-dimensional basic element airfoils along the blade span from the blade root to the blade tip. The number of basic element airfoils is determined according to the blade span and the requirements for shaping accuracy, and it is necessary to ensure that each basic element airfoil can cover the entire blade height.

[0023] The inlet geometry, maximum thickness, and maximum thickness position of each basic airfoil can be determined based on the stator inlet geometry, the maximum thickness of the support plate, the position of the maximum thickness of the support plate, and the relative position of the support plate's trailing edge.

[0024] The chord length of the basic airfoil at different spanwise positions is adjusted based on the sweep margin of the fan's last-stage stator. In this embodiment, the chord length of the basic airfoil at the blade root position is first determined. Specifically, the basic airfoil is divided into a stator segment and a support segment. The chord length of the stator segment at the blade root position is determined. Since the position of the support segment's maximum thickness relative to the trailing edge is determined, the distance between the maximum thickness position and the stator segment is adjusted according to the compactness requirements of the stator segment and the support segment, thereby determining the chord length of the basic airfoil at the blade root position. For adjusting the chord length of the basic airfoil at other spanwise positions, since the position of the support segment's maximum thickness relative to the trailing edge is determined, it is only necessary to adjust the chord length of the stator segment of the basic airfoil at other spanwise positions based on the sweep margin of the fan's last-stage stator to determine the chord length of the basic airfoil at other spanwise positions. In a specific embodiment, the chord length of the blade shape of the blade root position element can be the same as the sum of the chord lengths of the stator and the support plate of the independent type, or the chord length of the blade shape of the blade root position element can be less than the sum of the chord lengths of the stator and the support plate of the independent type.

[0025] The bending angle distribution of the stator segments of the basic blade type at different spanwise positions is adjusted according to the bending amount of the three-dimensional shape of the fan's final stage stator.

[0026] By adjusting the chord length of each basic blade and the distribution of the stator segment bend angle, the stator segment structure is ensured to meet the design requirements of the three-dimensional stator shape of the fan's final stage.

[0027] By radially stacking the individual blade profiles, an integrated blade structure is obtained.

[0028] The specific steps for adjusting the bend angle distribution of the stator segments of the basic blade profile at different spanwise positions based on the bend amount of the three-dimensional shape of the fan's final stage stator include: The middle arc of the basic blade profile is divided into the stator middle arc segment and the support plate middle arc segment; The distribution of the bend angles of the arc segment in the support plate remains constant. Specifically, the distribution of the bend angles of the arc segment in the support plate is a straight shape and meets the design requirements of the intermediate casing support plate. By adjusting the intersection point of the arc segment in the stator and the arc segment in the support plate, as well as the distribution of the bend angle of the arc segment in the stator, the flow path turn of the stator segment can be made to meet the specific design requirements of the fan's last-stage stator, while ensuring a smooth transition between the stator segment and the support plate segment of the integrated blade structure. In particular, by adjusting the distribution of the bend angle of the arc segment in the stator, the circumferential position of the suction and pressure surfaces of the integrated blade stator segment is changed.

[0029] At the same spanwise position and along the engine's axial direction, the distance between the maximum thickness position of the basic airfoil of the integrated blade structure and its trailing edge is equal to the distance between the maximum thickness position of the intermediate casing support plate and its trailing edge. This ensures that the absolute position of the maximum thickness position of the basic airfoil of the integrated blade structure relative to its trailing edge at the same spanwise position is consistent with the absolute position of the maximum thickness position of the intermediate casing support plate relative to its trailing edge. Furthermore, at the same spanwise position, the maximum thickness value of the basic airfoil of the integrated blade structure is equal to the maximum thickness value of the intermediate casing support plate. During the radial stacking of the basic airfoils, the trailing edges of each basic airfoil are aligned during radial stacking. This ensures that the thickness distribution of the support plate section is consistent with the thickness distribution of the intermediate casing support plate.

[0030] This application adopts a two-stage blade shape modeling method with intermediate arc and thickness distribution, as well as a three-dimensional stacking method that matches engineering requirements. It has a high degree of freedom, which can meet the structural strength requirements of the intermediate casing support plate, while retaining the original aerodynamic shape of the fan's final stage stator. Moreover, the process is simple, and the final geometry can be obtained in just one modeling step.

[0031] The design of the fan final stage stator and intermediate casing support plate in this application is an integrated design, which eliminates the safety gap that needs to be reserved when the fan final stage stator and intermediate casing support plate are set separately. This reduces the space occupied and realizes a compact intermediate casing design that is integrated with the upstream fan final stage stator.

[0032] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A design method for a fan final stage stator and intermediate casing support plate, characterized in that, The fan's final stage stator and intermediate casing support plate are designed as an integrated blade structure, which includes a stator section and a support plate section. The styling method includes the following steps: Determine the number and distribution of spanwise blade elements in the integrated blade structure; The inlet geometry, maximum thickness, and maximum thickness position of each basic airfoil are determined based on the stator inlet geometry, the maximum thickness of the support plate, the position of the maximum thickness of the support plate, and the relative position of the support plate's trailing edge. Adjust the chord length of the basic blade profiles at different spanwise positions based on the sweep of the three-dimensional shape of the fan's final stage stator; The bending angle distribution of the stator segments of the basic blade profile at different spanwise positions is adjusted according to the bending amount of the three-dimensional shape of the fan's final stage stator. By radially stacking the individual blade profiles, an integrated blade structure is obtained.

2. The design method for the fan final stage stator and intermediate casing support plate according to claim 1, characterized in that, The specific steps for adjusting the bend angle distribution of the stator segments of the basic blade profile at different spanwise positions based on the bend amount of the three-dimensional shape of the fan's final stage stator include: The middle arc of the basic blade profile is divided into the stator middle arc segment and the support plate middle arc segment; Keep the angle distribution of the arc segment in the support plate constant; Adjust the intersection point of the arc segment in the stator and the arc segment in the support plate, as well as the distribution of the bending angle of the arc segment in the stator.

3. The design method for the fan final stage stator and intermediate casing support plate according to claim 1, characterized in that, At the same spanwise position and along the axial direction of the engine, the distance between the maximum thickness position of the basic blade profile of the integrated blade structure and the trailing edge of the basic blade profile is equal to the distance between the maximum thickness position of the intermediate casing support plate and the trailing edge of the intermediate casing support plate.

4. The design method for the fan final stage stator and intermediate casing support plate according to claim 1, characterized in that, At the same spanwise position, the maximum thickness of the basic airfoil of the integrated blade structure is equal to the maximum thickness of the intermediate casing support plate.

5. The design method for the fan final stage stator and intermediate casing support plate according to claim 1, characterized in that, During the radial stacking of the basic airfoils, the trailing edges of the basic airfoils are aligned and radially stacked.

6. The design method for the fan final stage stator and intermediate casing support plate according to claim 1, characterized in that, The stator section and the support plate section of the integrated blade structure have a smooth transition.

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