A Modeling Method for a Leading-Edge Damaged Blade and a Simulation Method for the Aerodynamic Characteristics of a Full-Ring Fan Blade

Abstract

On the one hand, the present application provides a method for modeling a leading-edge damaged blade, including: extracting the airfoil coordinates of different blade height cross-sections, and calculating the mean camber line and thickness distribution of each airfoil; for the airfoil with a leading-edge curling damage, taking point A as the starting point and point P as the center to make an arc with an arc length of s, and superimposing the corresponding thickness distribution on the arc to obtain the airfoil suffering from curling damage, where point A is the termination position of the curl on the mean camber line, PA = s / (2θ), and PA is perpendicular to the outer tangent AQ of point A on the mean camber line, s is the length from point A on the mean camber line to the leading-edge point L, and θ is the curling angle; stacking each airfoil of the blade along the blade height direction to obtain a three-dimensional model of the leading-edge damaged blade. On the other hand, a method for simulating the aerodynamic characteristics of a full-ring fan blade is provided, and this simulation method is implemented based on the above-mentioned method for modeling a leading-edge damaged blade.

Description

Technical Field

[0001] This application belongs to the field of aerodynamic characteristic simulation methods for full - ring fan blades, and particularly relates to a method for modeling leading - edge damaged blades and simulating the aerodynamic characteristics of full - ring fan blades. Background Technique

[0002] The fan blades of aero - engines are prone to bird strikes during aircraft take - off and landing, which can damage the fan blades. The leading edge of the damaged fan blade will undergo curling deformation or curling plus chip - off deformation.

[0003] To simulate the aerodynamic characteristics of the full - ring fan blade after a bird strike, it is necessary to construct three - dimensional models of a relatively large number of fan blades with damaged leading edges.

[0004] Currently, when simulating the aerodynamic characteristics of the full - ring fan blade after a bird strike, for the construction of the three - dimensional model of the fan blade with damaged leading edge, most often the finite - element method is used to simulate the bird - strike process to obtain the structure of the fan blade with damaged leading edge, and then the corresponding fan blade is corrected in three - dimensional software. The modeling time is long. In the case of a large number of fan blades with damaged leading edges, it takes a lot of time, and the degree of damage of the modeled fan blade is not easy to quantify and describe.

[0005] In view of the existence of the above - mentioned technical defects, this application is proposed.

[0006] It should be noted that the disclosure of the above background - technique content is only used to assist in understanding the inventive concept and technical solution of the present invention, and it does not necessarily belong to the prior art of this patent application. Without clear evidence indicating that the above content was publicly available on the filing date of this application, the above background technique should not be used to evaluate the novelty and inventiveness of this application. Summary of the Invention

[0007] The purpose of this application is to provide a method for modeling leading - edge damaged blades and simulating the aerodynamic characteristics of full - ring fan blades to overcome or mitigate at least one aspect of the known existing technical defects.

[0008] The technical solution of this application is as follows:

[0009] On the one hand, a method for modeling leading - edge damaged blades is provided, including:

[0010] Extract the airfoil coordinates of different blade height cross - sections, and calculate the mean camber line and thickness distribution of each airfoil;

[0011] For a blade profile with a curled edge damage at the leading edge, an arc line with an arc length of s is drawn with point A as the starting point and point P as the center. The corresponding thickness distribution is superimposed on the arc line to obtain the blade profile suffering from the curled edge damage. Among them, point A is the termination position of the curled edge on the middle arc, PA = s / (2θ), and PA is perpendicular to the outer tangent AQ of point A on the middle arc. s is the length from point A on the middle arc to the leading edge point L, and θ is the curling angle;

[0012] Stack the blade profiles of each blade along the blade height direction to obtain a three-dimensional model of the blade with leading edge damage.

[0013] According to at least one embodiment of the present application, in the above-mentioned method for modeling a blade with leading edge damage, for a blade profile with a curled edge and chip removal damage at the leading edge, an arc line with an arc length of is drawn with point A as the starting point and point P as the center. A semi-ellipse with a short axis corresponding to the blade thickness and a long axis twice the short axis is constructed at point B. The corresponding thickness distribution is superimposed on the arc line to obtain the blade profile suffering from the curled edge and chip removal damage. Among them, point A is the termination position of the curled edge on the middle arc, PA = s / (2θ), and PA is perpendicular to the outer tangent AQ of point A on the middle arc. s is the length from point A on the middle arc to the leading edge point L, and θ is the curling angle, is equal to the length of the chip removal, and point B corresponds to the termination position of the chip removal on the middle arc.

[0014] On the other hand, a method for simulating the aerodynamic characteristics of a full-ring fan blade is provided, including:

[0015] Construct three-dimensional models of each fan blade. Among them, for the three-dimensional model of the blade with leading edge damage, it is constructed by any of the above-mentioned methods for modeling a blade with leading edge damage;

[0016] Splice the three-dimensional models of each fan blade in sequence to form a three-dimensional model of the full-ring fan blade, generate a grid, and perform aerodynamic characteristic simulation.

[0017] According to at least one embodiment of the present application, in the above-mentioned method for simulating the aerodynamic characteristics of a full-ring fan blade, calculate the windward damage area of each blade with leading edge damage, and sum them up to obtain the total windward damage area of the full-ring fan blade;

[0018] Correlate the total windward damage area of the full-ring fan blade with its aerodynamic characteristics.

[0019] According to at least one embodiment of the present application, in the above-mentioned method for simulating the aerodynamic characteristics of a full-ring fan blade, the specific calculation of the windward damage area of each blade with leading edge damage is as follows:

[0020] Project each blade with leading edge damage along the axial direction of the full-ring fan blade, and use the area difference between its projection and the projection of the blade without leading edge damage as the windward damage area. Brief Description of the Drawings

[0021] Figure 1 It is a schematic diagram of a blade with a curled edge damage at the leading edge provided by an embodiment of the present application;

[0022] Figure 2 It is a schematic diagram of an airfoil with a curled edge damage at the leading edge provided by an embodiment of the present application;

[0023] Figure 3 It is a schematic diagram of the windward damage area of a blade with a curled edge damage at the leading edge provided by an embodiment of the present application;

[0024] Figure 4 It is a schematic diagram of a blade with a curled edge and chip damage at the leading edge provided by an embodiment of the present application;

[0025] Figure 5 It is a schematic diagram of an airfoil with a curled edge and chip damage at the leading edge provided by an embodiment of the present application;

[0026] Figure 6 It is a schematic diagram of the windward damage area of a blade with a curled edge and chip damage at the leading edge provided by an embodiment of the present application;

[0027] Figure 7 It is a schematic diagram of a full - ring fan blade provided by an embodiment of the present application.

[0028] For better illustration of this embodiment, some components in the drawings are omitted, enlarged or reduced, which do not represent the dimensions of the actual product; in addition, the drawings are for illustrative purposes only, and their positional relationships are limited to illustrative purposes and cannot be construed as a limitation of this patent. Detailed implementation manners

[0029] To make the technical solutions of the present application and their advantages clearer, the technical solutions of the present application will be further described clearly and completely below with reference to the drawings. It can be understood that the specific embodiments described herein are only partial embodiments of the present application, which are only used to explain the present application and not to limit the present application. It should be noted that for the convenience of description, only the parts related to the present application are shown in the drawings, and other related parts can refer to the general design. Without conflict, the embodiments in the present application and the technical features in the embodiments can be combined with each other to obtain new embodiments.

[0030] In addition, unless otherwise defined, the technical terms or scientific terms used in the description of this application shall have the ordinary meanings understood by those of ordinary skill in the art to which this application pertains. The words indicating directions such as "upper", "lower", "left", "right", "center", "vertical", "horizontal", "inner", "outer", etc. used in the description of this application are only used to indicate relative directions or positional relationships, rather than implying that the device or component must have a specific orientation, be constructed and operated in a specific orientation. When the absolute position of the object being described changes, its relative positional relationship may also change accordingly. Therefore, it should not be construed as a limitation to this application. The terms "first", "second", "third", and similar terms used in the description of this application are only for descriptive purposes to distinguish different components, and cannot be construed as indicating or implying relative importance. The similar words such as "a", "an", or "the" used in the description of this application should not be construed as an absolute limitation on the quantity, but should be understood as having at least one. The similar words such as "including" or "comprising" used in the description of this application are intended to mean that the elements or objects appearing before this word cover the elements or objects listed after this word and their equivalents, without excluding other elements or objects.

[0031] In addition, it should be noted that, unless otherwise clearly specified and limited, the similar words such as "installed", "connected", and "joined" used in the description of this application should be understood in a broad sense. For example, the connection can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and can also be the communication inside two components. Those skilled in the art can understand its specific meaning in this application according to the specific situation.

[0032] The following further elaborates on this application with reference to the Figures 1 to 7 drawings.

[0033] On the one hand, a method for modeling a leading-edge damaged blade is provided, including:

[0034] Extracting the airfoil coordinates of different blade height cross-sections, and calculating the mean camber line and thickness distribution of each airfoil;

[0035] For the airfoil with a leading-edge curling damage, taking point A as the starting point and point P as the center to make a circular arc line with an arc length of s, and superimposing the corresponding thickness distribution on the circular arc line to obtain the airfoil suffering from curling damage, where point A is the termination position of the curl on the mean camber line, PA = s / (2θ), and PA is perpendicular to the outer tangent AQ of point A on the mean camber line, s is the length from point A on the mean camber line to the leading-edge point L, and θ is the curling angle;

[0036] Stacking each airfoil of the blade along the blade height direction to obtain a three-dimensional model of the leading-edge damaged blade.

[0037] For the leading-edge damaged blade modeling method disclosed in the above embodiments, those skilled in the art can understand that it decomposes the construction of the three-dimensional model of the blade with a curled leading edge into parametric construction of multiple two-dimensional airfoils along the blade height direction, and stacks the constructed two-dimensional airfoils along the blade height direction to obtain the three-dimensional model of the leading-edge damaged blade, which has a high construction efficiency.

[0038] For the leading-edge damaged blade modeling method disclosed in the above embodiments, those skilled in the art can also understand that it is considered that the leading-edge curled damaged part of the blade with a curled leading edge undergoes an arc deformation on the two-dimensional airfoil, the mean camber line undergoes an arc bend, and the length of the mean camber line does not change before and after deformation, that is, AL = AM, where M is the position of the leading-edge point after the mean camber line deformation, and the curling angle is the chord tangent angle of the mean camber line at point A. When specifically applying the leading-edge damaged blade modeling method provided in this application, an external tangent AQ of point A on the mean camber line can be made according to the slope of point A on the mean camber line, a perpendicular line to the external tangent AQ is made through point A, and a point at the length s / (2θ) on the perpendicular line is taken as point P.

[0039] In some alternative embodiments, in the above-mentioned leading-edge damaged blade modeling method, for the airfoil with a curled and chipped leading edge, an arc line with an arc length of is drawn with point A as the starting point and point P as the center of the circle. A semi-ellipse with a minor axis corresponding to the airfoil thickness and a major axis twice the minor axis is constructed at point B, and the corresponding thickness distribution is superimposed on the arc line to obtain the airfoil suffering from curled and chipped damage, where point A is the termination position of the curl on the mean camber line, PA = s / (2θ), and PA is perpendicular to the external tangent AQ of point A on the mean camber line, s is the length from point A on the mean camber line to the leading-edge point L, θ is the curling angle, is equal to the length of the chip, and point B corresponds to the termination position of the chip on the mean camber line.

[0040] For the leading-edge damaged blade modeling method disclosed in the above embodiments, those skilled in the art can understand that when the blade is struck by a bird, it will first undergo curled damage, and when the curled damage reaches a certain degree, chipped damage will occur, that is, curled and chipped damage will occur. Therefore, for the airfoil with a curled and chipped leading edge, it can be first considered that it undergoes curled damage, and an arc line is constructed according to the construction method of the airfoil with a curled leading edge. Then, the termination point of the chip is found on the arc line and interrupted, that is, the part between the termination point of the chip on the arc line and the leading-edge point is deleted. With the termination point of the chip as the center of the semi-ellipse and the corresponding airfoil thickness as the minor axis, a semi-ellipse with a major axis twice the minor axis is constructed, and the thickness distribution is filled, and the junction part is smoothly transitioned to obtain the airfoil suffering from curled and chipped damage.

[0041] On the other hand, a method for simulating the aerodynamic characteristics of a full-ring fan blade is provided, including:

[0042] Construct three-dimensional models of each fan blade. Among them, for the three-dimensional model of the blade with leading-edge damage, it is constructed by any of the above-mentioned leading-edge damage blade modeling methods.

[0043] Splice the three-dimensional models of each fan blade in sequence into a full-ring fan blade three-dimensional model, generate a grid, and perform aerodynamic characteristic simulation.

[0044] For the full-ring fan blade aerodynamic characteristic simulation method disclosed in the above embodiments, which is implemented based on the leading-edge damage blade modeling method disclosed in the above embodiments, the description is relatively simple. For specific related parts, reference can be made to the description of the relevant part of the leading-edge damage blade modeling method, and its technical effects can also be referred to the technical effects of the relevant part of the leading-edge damage blade modeling method, which will not be elaborated here.

[0045] In some alternative embodiments, in the above full-ring fan blade aerodynamic characteristic simulation method, calculate the windward damage area of each blade with leading-edge damage, and sum them to obtain the total windward damage area of the full-ring fan blade.

[0046] Correlate the total windward damage area of the full-ring fan blade with its aerodynamic characteristics.

[0047] In some alternative embodiments, in the above full-ring fan blade aerodynamic characteristic simulation method, the calculation of the windward damage area of each blade with leading-edge damage is specifically as follows:

[0048] Project each blade with leading-edge damage along the axial direction of the full-ring fan blade, and use the area difference between its projection and the projection of the blade without leading-edge damage as the windward damage area.

[0049] For the full-ring fan blade aerodynamic characteristic simulation method disclosed in the above embodiments, those skilled in the art can understand that it discloses a calculation method for the windward damage area of the blade with leading-edge damage, and sums the windward damage areas of each blade with leading-edge damage as the total windward damage area of the full-ring fan blade, and correlates the total windward damage area of the full-ring fan blade with its aerodynamic characteristics to realize the quantification of the damage degree and the attenuation degree of aerodynamic performance of the full-ring fan blade.

[0050] The various embodiments in the specification are described in a progressive manner. Each embodiment focuses on the differences from other embodiments. For the same or similar parts among the various embodiments, reference can be made to each other.

[0051] So far, the technical solution of the present application has been described in conjunction with the preferred embodiments shown in the accompanying drawings. Those skilled in the art should understand that the protection scope of the present application is obviously not limited to these specific embodiments. Without departing from the principle of the present application, those skilled in the art can make equivalent changes or substitutions to the relevant technical features, and the technical solutions after these changes or substitutions will fall within the protection scope of the present application.

Claims

1. A method for modeling a leading-edge damaged blade, characterized in that Including: Extract the airfoil coordinates of different height cross-sections of the blade, and calculate the mean camber line and thickness distribution of each airfoil; For the airfoil with a curled edge damage at the leading edge, take point A as the starting point and point P as the center to make an arc with a length of s. Superimpose the corresponding thickness distribution on the arc to obtain the airfoil suffering from the curled edge damage, where point A is the termination position of the curled edge on the mean camber line, PA = s / (2θ), and PA is perpendicular to the outer tangent AQ of point A on the mean camber line, s is the length from point A on the mean camber line to the leading edge point L, and θ is the curling angle; Stack the airfoils of the blade along the height direction to obtain a three-dimensional model of the blade with leading edge damage.

2. The method for modeling a blade with leading edge damage according to claim 1, wherein: For the blade profile with a curled edge and a chip-off damage at the leading edge, an arc with point A as the starting point and point P as the center and an arc length of is drawn. At point B, a semi-ellipse with the minor axis corresponding to the blade thickness and the major axis twice the minor axis is constructed, and the corresponding thickness distribution is superimposed on the arc line to obtain the blade profile suffering from the curled edge and chip-off damage. Among them, point A is the termination position of the curled edge on the mid-arc line, PA = s / (2θ), and PA is perpendicular to the outer tangent AQ of point A on the mid-arc line. s is the length from point A on the mid-arc line to the leading edge point L, and θ is the curling angle, is equal to the length of the chip-off, and point B corresponds to the termination position of the chip-off on the mid-arc line.

3. A simulation method for the aerodynamic characteristics of a full-ring fan blade, characterized in that, Including: Construct a three-dimensional model of each fan blade. For the three-dimensional model of the blade with leading edge damage, it is constructed by the method for modeling a blade with leading edge damage according to any one of claims 1-2; Splice the three-dimensional models of each fan blade in sequence to form a three-dimensional model of a full-ring fan blade, generate a mesh, and perform an aerodynamic characteristic simulation.

4. The method for simulating the aerodynamic characteristics of a full-ring fan blade according to claim 3, wherein: Calculate the windward damage area of each blade with leading edge damage, and sum them up to obtain the total windward damage area of the full-ring fan blade; Correlate the total windward damage area of the full-ring fan blade with its aerodynamic characteristics.

5. The method for simulating the aerodynamic characteristics of a full-ring fan blade according to claim 3, wherein: The calculation of the windward damage area of each blade with leading edge damage is specifically: Project each blade with leading edge damage along the axial direction of the full-ring fan blade, and take the area difference between its projection and the projection of the blade without leading edge damage as the windward damage area.

Images