Engine blade design method based on high-quality curved surface

Abstract

The invention discloses an engine blade design method based on a high-quality curved surface. The engine blade design method comprises the following steps: S1, constructing a two-dimensional section of a turbine engine blade according to key parameters and a mathematical geometrical relationship; s2, constructing a three-dimensional model of the turbine engine blade by combining the two-dimensional cross section with a blade front edge vertex equation and a blade rear edge vertex equation; s3, performing high-quality optimization on the two-dimensional section of the turbine engine blade by referring to a high-quality curved surface standard; s4, performing high-quality optimization on the three-dimensional model of the turbine engine in combination with a high-quality curved surface standard; and S5, detecting the high-quality turbine engine blade model. According to the method, a turbine engine blade high-quality model which has good aerodynamic performance and meets a high-quality curved surface process is designed through parametric modeling, and the feasibility and effectiveness of the design and optimization method in the paper are verified through a fluid mechanics simulation experiment.

Description

TECHNICAL FIELD

[0001] The application relates to the technical field of unmanned aerial vehicle shape design, in particular to an engine blade design method based on high-quality curved surfaces. BACKGROUND

[0002] The high-quality curved surface definition, technical standards that the high-quality curved surface should have, in combination with the related standards of the A-level curved surface in the automobile field, the standards matched with the turbine engine blade model are formulated, and the turbine engine blade model construction standard is improved to meet the high-quality curved surface standard.

[0003] High aerodynamic performance, the turbine engine blade with high-quality design plays a key role in the turbine engine. After determining the related design requirements of the aircraft turbine engine blade, the main turbine engine blade parameters are completely determined. The key content of the high-quality turbine engine blade is the construction of the high-quality model of the turbine engine blade, high-precision optimization, so as to achieve the goal of improving the aerodynamic efficiency.

[0004] The high-quality curved surface technology can be used to create a surface model with high complexity, smoothness and high precision. This method is generally applied in the CAD and computer drawing process to produce the shape surface of products such as automobiles, aircraft, ships and the like.

[0005] At present, the high-quality curved surface has not been applied to the turbine engine blade modeling design, and the application of the high-quality curved surface in the aviation field has far-reaching significance for improving the performance, efficiency and appearance of the aircraft. The high-quality curved surface will bring more innovation and breakthrough to the aviation industry. SUMMARY

[0006] Therefore, the purpose of the application is to provide an engine blade design method based on high-quality curved surfaces, which designs a turbine engine blade high-quality model with good aerodynamic performance and high-quality curved surface process through parameterized modeling, and verifies the feasibility and effectiveness of the design and optimization method in this paper through fluid mechanics simulation experiment.

[0007] The technical problem solved by the application adopts the following technical scheme:

[0008] An engine blade design method based on high-quality curved surfaces comprises the following steps:

[0009] S1, constructing a two-dimensional section of a turbine engine blade according to key parameters and mathematical geometric relations;

[0010] S2, constructing a three-dimensional model of the turbine engine blade in combination with the two-dimensional section and the vertex equation of the blade leading edge and trailing edge;

[0011] S3, high-quality optimization is performed on the two-dimensional section of the turbine engine blade by referring to the high-quality curved surface standard;

[0012] S4, high-quality optimization is performed on the three-dimensional model of the turbine engine by referring to the high-quality curved surface standard;

[0013] S5, detection is performed on the high-quality turbine engine blade model.

[0014] Further, in S2, the method for constructing the three-dimensional model of the turbine engine blade by combining the two-dimensional section with the vertex equations of the leading edge and the trailing edge is as follows:

[0015] Two guide lines are selected for the construction of the turbine engine blade model, the position equations of the points on the leading edge and the trailing edge are created based on the positions of the vertexes of the leading edge and the trailing edge, and the three-dimensional model of the turbine engine blade is constructed by using the sweep of the two guide lines.

[0016] Further, in S3, the method for high-quality optimization of the two-dimensional section of the turbine engine blade by referring to the high-quality curved surface standard is as follows:

[0017] The standard of the high-quality curved surface is that the continuity reaches G2 according to the requirements of A-level curved surface in the automobile field; G0 continuity is point continuity, the points are connected together at the connection of the curves or the curved surfaces, but the tangent continuity is not met; G1 continuity is tangent continuity, the tangent directions of the connected points are the same, which meets the G1 continuity; G2 continuity is curvature continuity, the curvatures at the connection of the two curves or the curved surfaces are the same, which meets the G2 continuity; in the case of having obtained the two-dimensional section of the turbine engine blade, the two-dimensional section of the turbine engine blade is optimized to the G2 standard by referring to the high-quality curved surface, which meets the G2 continuity of the two-dimensional section of the turbine engine blade, by adding the key control points, adding the control of the tangent direction and the tangent rate, and optimizing the two-dimensional section of the turbine engine blade to the G1 standard, and then combining the related instructions of the fairing curve to optimize the section to the G2 continuity.

[0018] Further, in S4, the method for high-quality optimization of the three-dimensional model of the turbine engine by referring to the high-quality curved surface standard is as follows:

[0019] Three two-dimensional sections are constructed by combining the three section parameter data, which are the top section, the middle section and the bottom section of the turbine engine blade, the three two-dimensional sections are respectively processed by fairing to meet the G2 continuity, and then the three-dimensional model of the turbine engine is swept out by sequentially selecting the three two-dimensional sections by using the multi-section sweep method.

[0020] Further, in S5, the method for detecting the high-quality turbine engine blade model is as follows:

[0021] With the isocline mapping and Gauss square root detection diagram analysis, the zebra stripe is clear and flawless, and meets the G2 continuity requirement, and the Gauss square root detection diagram is relatively smooth, and meets the requirement.

[0022] Further, S6 is further included, simulation experiment preprocessing is carried out by using SpaceClaim, and the method comprises the following steps:

[0023] The turbine engine blade is simulated in the normal working environment of the turbine engine, and the aerodynamic performance of the low-quality turbine engine blade and the high-quality turbine engine blade under the same environmental conditions is compared; in order to simulate the environment of the turbine engine blade in the turbine engine, a fluid mechanics simulation fluid domain is constructed, and the range of the simulation fluid domain is: the spline line of the blade basin is stretched to the blade back direction by one blade pitch, the spline line of the blade back is stretched to the blade basin direction by one blade pitch, the leading edge part of the blade is stretched forward by 1.5 times the chord length, and the trailing edge part of the blade is stretched backward by 2 times the chord length, and the closed fluid domain is constructed; in Fluent, the finite element mesh division function is used, the tetrahedron and hexahedron mixed grid is selected, and the turbine engine blade model fluid domain finite element meshing model is constructed.

[0024] Further, S7 is further included, and the fluid simulation experiment is carried out by using Fluent after the preprocessing is completed.

[0025] The engine blade design method based on the high-quality surface has the following beneficial effects:

[0026] The engine blade design method based on the high-quality surface is provided, the turbine engine blade designed by the high-quality surface has lower curvature and is smoother, and the model aerodynamic performance is better; the fluid mechanics simulation experiment model is used to verify that the constructed turbine engine blade has high quality, can perform better aerodynamic performance in the fluid mechanics simulation experiment, and prove that the constructed turbine engine blade model meets the high quality. BRIEF DESCRIPTION OF DRAWINGS

[0027] Figure 1 The method flowchart of the application is shown in the figure;

[0028] Figure 2 The turbine engine blade three-dimensional model is constructed by using two guide lines in the figure;

[0029] Figure 3 The high-quality optimization schematic diagram of the turbine engine blade two-dimensional section is shown in the figure;

[0030] Figure 4 The high-quality optimization schematic diagram of the turbine engine three-dimensional model is shown in the figure;

[0031] Figure 5A high-quality turbine engine blade model detection schematic diagram of the present application;

[0032] Figure 6 A simulation experiment preprocessing diagram of the present application using SpaceClaim;

[0033] Figure 7 A high-quality model fluid simulation experiment schematic diagram of the present application using Fluent;

[0034] Figure 8 A low-quality model fluid simulation experiment schematic diagram of the present application using Fluent;

[0035] Figure 9 A turbine engine two-dimensional section view after adding auxiliary control points in the embodiment. DETAILED DESCRIPTION

[0036] In order to make the purpose, technical scheme and advantages of the embodiments of the present application clearer, the technical scheme in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application.

[0037] REFERENCE Figure 1 The present application provides a high-quality surface-based engine blade design method, a turbine engine blade two-dimensional section model is constructed based on turbine engine blade parameters and mathematical geometric relationships, a low-quality turbine engine blade model is constructed by using the sweep of two guide lines, and then a high-quality surface design principle is combined to optimize the two-dimensional section by using the method of adding auxiliary control points. Then, multiple two-dimensional sections constructed by combining multiple turbine engine blade section data are swept to obtain a turbine engine blade three-dimensional model that meets the high-quality surface. The three-dimensional model of the designed turbine engine blade is subjected to fluid mechanics test, and the aerodynamic performance is analyzed. The specific method and process are as follows:

[0038] S1, a turbine engine blade two-dimensional section is constructed according to key parameters and mathematical geometric relationships;

[0039] S2, a turbine engine blade three-dimensional model is constructed by combining the two-dimensional section and the blade leading edge and trailing edge vertex equation, and the method is as follows:

[0040] Two guide lines are selected for the construction of the turbine engine blade model, the position equation of the leading edge and trailing edge points is created based on the positions of the leading edge and trailing edge vertices of the two-dimensional section, and the turbine engine blade three-dimensional model is constructed by using the sweep of the two guide lines. Figure 2(a) is a schematic diagram of the sweep of two guide lines; Figure 2 (b) is a three-dimensional model diagram swept by two guide lines.

[0041] S3, with reference to the high-quality curved surface standard, the two-dimensional section of the turbine engine blade is optimized in high quality, and the method is as follows:

[0042] The standard of high-quality curved surface, combined with the requirement of A-level curved surface in the field of automobile, the continuity is at least G2; G0 continuity is point continuity, at the connection of curves or curved surfaces, the points are connected together, but the tangent continuity is not met, G1 continuity is tangent continuity, the tangent directions of the connection points are the same, that is, G1 continuity is met, G2 continuity is curvature continuity, the curvatures at the connection of two curves or curved surfaces are the same, that is, G2 continuity is met; in the case that the two-dimensional section of the turbine engine blade has been obtained, with reference to the high-quality curved surface, the two-dimensional section of the turbine engine blade is optimized in high quality, the continuity of the two-dimensional section of the turbine engine blade is optimized to G2 standard, first, key control points are added, the control of tangent direction and tangent rate is added, the continuity of the two-dimensional section of the turbine engine blade is optimized to G1 standard, and then the section is optimized to G2 continuity in combination with the related instructions of fairing curve. Figure 3 (a) is an arrow-shaped curvature analysis diagram of the two-dimensional section meeting G1 continuity, Figure 3 (b) is a fairing curve input diagram meeting G2 continuity.

[0043] S4, the three-dimensional model of the turbine engine is optimized in high quality in combination with the high-quality curved surface standard, and the method is as follows:

[0044] Figure 4 (a) is a schematic diagram of three two-dimensional sections, three two-dimensional sections are constructed in combination with three section parameter data, which are respectively a top section, a middle section and a bottom section of the turbine engine blade, the three two-dimensional sections are respectively processed by fairing, so that G2 continuity is met, then the three two-dimensional sections are sequentially selected by using the multi-section sweep method, and finally a three-dimensional model of the turbine engine is swept out, as shown in Figure 4 (b).

[0045] In the high-quality curved surface, the curved surface continuity is at least G2 continuity, so the multi-section sweep method is selected to more accurately describe the details of the turbine engine blade, three two-dimensional models of the turbine engine blade with key section characteristics at the bottom, the middle and the top are selected, based on the parameters of the two-dimensional sections, the sections are constructed, and then the three sections are sequentially selected to sweep, so that a high-quality three-dimensional model of the turbine engine blade is constructed.

[0046] S5, the high-quality turbine engine blade model is detected, and the method is as follows:

[0047] The turbine engine blade model with high quality can be verified by using the contour plot and Gaussian square root detection plot analysis. Figure 5 The contour plot of the three-dimensional model of the blade of (a) shows that the zebra pattern is clear and flawless, meeting the requirement of G2 continuity, and the Gaussian square root detection plot is relatively smooth, meeting the requirement. Referring to Figure 5 the Gaussian square root curvature detection plot of the three-dimensional model of the blade of (b).

[0048] S6, simulation experiment pretreatment is carried out by using SpaceClaim, and the method is as follows:

[0049] The aerodynamic performance analysis experiment is to simulate the normal working environment of the turbine engine blade in the turbine engine, and to compare the aerodynamic performance of the low-quality turbine engine blade and the high-quality turbine engine blade under the same environmental conditions; in order to simulate the environment of the turbine engine blade in the turbine engine, the fluid domain of the fluid mechanics simulation is constructed, and the range of the simulation fluid domain constructed this time is: the spline line of the blade basin is stretched to the blade back direction by one blade pitch, the spline line of the blade back is stretched to the blade basin direction by one blade pitch, the leading edge of the blade is stretched forward by 1.5 times the chord length, and the trailing edge of the blade is stretched backward by 2 times the chord length, and the closed fluid domain is constructed, Figure 6 (a) is a schematic diagram of the inlet and outlet of the simulation experiment fluid domain; in Fluent, the finite element mesh division function is used, the tetrahedron and hexahedron mixed grid is selected, and the turbine engine blade model fluid domain finite element meshing model can be constructed by selecting this fluid domain, Figure 6 (b) is a finite element meshing analysis diagram of the simulation experiment fluid domain.

[0050] S7, complete pretreatment, and use Fluent to carry out fluid simulation experiment.

[0051] After the fluid domain is constructed, the fluid simulation experiment is carried out, and the simulation experiment conditions are set as follows: the inlet pressure is 1310000 Pa, the inlet temperature is 1630 K, and the outlet pressure is 593000 Pa. The fluid mechanics simulation experiment is carried out, and the simulation experiment results are analyzed, as shown in Table 1:

[0052]

[0053] Table 1

[0054] Figure 7 (a) is the velocity change diagram of the high-quality model fluid domain, Figure 7 (b) is the static pressure change diagram of the high-quality model fluid domain, Figure 8 (a) is the velocity change diagram of the low-quality model fluid domain, Figure 8 (b) is the static pressure change diagram of the low-quality model fluid domain, and the analysis of Table 1 and Figure 7 (a), Figure 7 (b),Figure 8 (a) and Figure 8 (b) can be known, the high-quality blade is greater than the low-quality blade, the outlet pressure is lower than the low-quality blade, that is, the fall pressure increases, and it is concluded that the high-quality turbine engine blade model has better aerodynamic performance in the simulation experiment than the low-quality model, so it can be verified from the simulation experiment data that the turbine engine blade model made has high quality.

[0055]

[0056]

[0057] Table 2

[0058] The application provides a high-quality surface-based engine blade design method. The turbine engine blade designed based on the high-quality surface has lower curvature and is smoother, and the constructed model has better aerodynamic performance. The fluid mechanics simulation experiment model is used to verify that the constructed turbine engine blade has high quality, can perform better aerodynamic performance in the fluid mechanics simulation experiment, and proves that the constructed turbine engine blade model meets the high quality.

[0059] Embodiment

[0060] Turbine engine blade modeling based on high-quality surface:

[0061] (1) Turbine engine blade:

[0062] The turbine engine blade is a very important part of the aircraft turbine engine component, and it is very important in the energy conversion of the turbine engine. Usually, a plurality of two-dimensional cross-sectional data of the turbine engine blade is intercepted to construct a two-dimensional model, and a plurality of cross sections are swept to construct a high-quality turbine engine blade model.

[0063] There are key control points in the turbine engine blade. The key control points are selected, the coordinates of the key control points are expressed by using mathematical geometric relations, the turbine engine blade top, middle and bottom cross-sectional data are brought in, and three turbine engine blade two-dimensional cross-sectional key control points are obtained. By using non-uniform rational B-spline fitting, a turbine engine blade two-dimensional cross section satisfying G0 continuity can be constructed. The two-dimensional cross section is connected by adding auxiliary control points to optimize the connection of the two-dimensional cross section. Three auxiliary control points are added in the blade basin part, and three auxiliary control points are added in the blade back part, as shown in Figure 9 The turbine engine blade two-dimensional cross-sectional key parameters are shown in Table 3:

[0064]

[0065]

[0066] Table 3

[0067] After optimizing the two-dimensional section to G1 continuity, the two-dimensional section of the turbine engine blade is optimized to meet the G2 continuity of the turbine engine blade by using the fairing curve method.

[0068] The two-dimensional section of the turbine engine blade is optimized with reference to the high-quality surface standard.

[0069] The three-dimensional model of the turbine engine is optimized with reference to the high-quality surface standard.

[0070] The high-quality turbine engine blade model is detected.

[0071] Finally, it should be noted that: the above examples are only used to illustrate the technical solutions of the present application, and not to limit it; although the present application has been described in detail with reference to the foregoing examples, those skilled in the art should understand: it can still modify the technical solutions recorded in the foregoing examples, or make equivalent replacement for part of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims

1. A method for designing an engine blade based on high-quality surfaces, characterized by, It comprises the following steps: S1, constructing a two-dimensional section of a turbine engine blade according to a key parameter and a mathematical geometric relationship; S2, constructing a three-dimensional model of the turbine engine blade in combination with the two-dimensional section and a leading edge and trailing edge vertex equation; S3, performing high-quality optimization on the two-dimensional section of the turbine engine blade by referring to a high-quality surface standard; S4, performing high-quality optimization on the three-dimensional model of the turbine engine by referring to the high-quality surface standard; S5, detecting the high-quality turbine engine blade model.

2. The method of designing an engine blade based on high quality surface according to claim 1, wherein, In S2, the method for constructing the three-dimensional model of the turbine engine blade in combination with the two-dimensional section and the leading edge and trailing edge vertex equation is as follows: Two guide lines are selected for sweeping to construct the three-dimensional model of the turbine engine blade, a position equation of the leading edge and trailing edge is created based on the positions of the leading edge and trailing edge vertices of the two-dimensional section, and the three-dimensional model of the turbine engine blade is constructed by sweeping the two guide lines.

3. The method of designing an engine blade based on high quality surface according to claim 2, characterized in that, In S3, the method for performing high-quality optimization on the two-dimensional section of the turbine engine blade by referring to the high-quality surface standard is as follows: The standard of the high-quality surface is that the continuity reaches G2 according to the requirements of the automotive field for A-level surfaces; G0 continuity is point continuity, the points are connected together at the connection of curves or surfaces, but the tangent continuity is not met; G1 continuity is tangent continuity, the tangent directions of the connected points are the same, which meets the G1 continuity; G2 continuity is curvature continuity, the curvatures at the connection of two curves or surfaces are the same, which meets the G2 continuity; in the case of having obtained the two-dimensional section of the turbine engine blade, the two-dimensional section of the turbine engine blade is optimized to the G2 standard by referring to the high-quality surface and meeting the G2 continuity requirement, first, a key control point is added, the tangent direction and the rate of change are controlled, the continuity of the two-dimensional section of the turbine engine blade is optimized to the G1 standard, and then the section is optimized to the G2 continuity by combining the related instructions of the fairing curve.

4. The method of designing an engine blade based on high quality surface according to claim 3, wherein, In S4, the method for performing high-quality optimization on the three-dimensional model of the turbine engine by referring to the high-quality surface standard is as follows: Three two-dimensional sections, i.e., a top section, a middle section and a bottom section of the turbine engine blade, are constructed by combining three section parameter data, the three two-dimensional sections are processed by fairing to meet the G2 continuity, and then the three-dimensional model of the turbine engine is swept out by sequentially selecting the three two-dimensional sections by using the multi-section sweeping method.

5. The method of designing an engine blade based on high quality surface according to claim 4, wherein, In S5, the method for detecting the high-quality turbine engine blade model is as follows: The analysis of the isocline mapping diagram and the Gaussian square root detection diagram shows that the zebra pattern is clear and flawless, and meets the requirement of G2 continuity, and the Gaussian square root detection diagram is relatively smooth, which meets the requirement.

6. The method of designing an engine blade based on high quality surface according to claim 5, wherein, S6, simulation experiment preprocessing is performed by using SpaceClaim, and the method comprises the following steps: The turbine engine blade is simulated in the environment of normal work in the turbine engine, and the aerodynamic performance of the low-quality turbine engine blade and the high-quality turbine engine blade is compared under the same environmental conditions; in order to simulate the environment of the turbine engine blade in the turbine engine, a fluid mechanics simulation fluid domain is constructed, and the range of the simulation fluid domain is that: the spline line of the blade basin is stretched to the blade back direction by one blade pitch, the spline line of the blade back is stretched to the blade basin direction by one blade basin pitch, the leading edge part of the blade is stretched forward by 1.5 times the chord length, and the trailing edge part of the blade is stretched backward by 2 times the chord length, so as to construct a closed fluid domain; in Fluent, the finite element mesh division function is used, the tetrahedron and hexahedron mixed mesh is selected, and the turbine engine blade model fluid domain finite element meshing model can be constructed by selecting the fluid domain.

7. The method of designing an engine blade based on high quality surface according to claim 6, wherein, S7, completing pretreatment, using Fluent to carry out fluid simulation experiment.

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