Method for obtaining HIRF induction field in aircraft propulsion system

Abstract

The invention provides a method for obtaining an HIRF induction field in an aircraft propulsion system. The method comprises the steps that the frequency range of an electromagnetic environment is obtained; according to the frequency range, grid division is carried out on the aircraft propulsion system complete machine simplified model, and an aircraft propulsion system complete machine model grid is obtained; performing material assignment on each grid in the aircraft propulsion system complete machine model grids to obtain aircraft propulsion system complete machine model grids with material attributes; in an aircraft propulsion system complete machine model grid with material attributes, setting measuring points according to the mounting position of airborne electronic equipment; setting HIRF electromagnetic excitation with preset electric field intensity; and obtaining the induced electric field intensity of the measuring point under the HIRF electromagnetic excitation. According to the method, meshing is carried out on the simplified model of the whole aircraft propulsion system, induction field differences caused by different electromagnetic coupling mechanisms in different electromagnetic environment frequency ranges are fully considered, and the electromagnetic field intensity of the measuring points in the whole aircraft propulsion system can be solved and calculated by using the minimum number of grids meeting the simulation precision.

Description

Technical Field

[0001] The present invention mainly relates to the technical field of electromagnetic environment effect, and in particular to a method for obtaining a HIRF induction field inside an aircraft propulsion system. Background Art

[0002] The electromagnetic protection design of commercial aircraft propulsion systems needs to be carried out during the R&D and design stage to ensure that they can operate reliably and permanently in the high-intensity radiated fields (HIRF) electromagnetic environment, thereby ensuring the flight safety of the aircraft. To carry out the electromagnetic protection design of the entire aircraft propulsion system, it is first necessary to obtain the electromagnetic environment induced internally by the entire aircraft propulsion system in the external HIRF environment, so as to lay out devices including airborne electronic and electrical equipment, airborne cables, etc. according to the induced electromagnetic environment.

[0003] At present, the electromagnetic protection design of the entire aircraft propulsion system is mostly based on industry standards and other documents or non-forward design through analogy with existing product prototypes. Electromagnetic protection design based on industry standards and other documents or analogy with existing product prototypes can easily lead to over-design of electromagnetic protection, resulting in increased design costs and extended development cycles. In addition, since the induced field strength of the specific installation and laying locations of the onboard system equipment inside the aircraft propulsion system is unknown in the actual HIRF electromagnetic environment, the design requirements to be verified in the test verification phase are unclear, and it is impossible to ensure that the electromagnetic protection design can meet the airworthiness requirements. In addition, the HIRF electromagnetic environment has a wide electromagnetic frequency range, and multiple transmitting antennas are required to cover different frequency ranges, which increases the economic and time costs of the electromagnetic protection design of the entire aircraft propulsion system. Summary of the invention

[0004] The technical problem to be solved by the present invention is to provide a method for obtaining the HIRF induction field inside an aircraft propulsion system, thereby solving the problem of high cost in current electromagnetic protection design.

[0005] To solve the above technical problems, the present invention provides a method for obtaining a HIRF induction field inside an aircraft propulsion system, comprising: obtaining a frequency range of an electromagnetic environment; meshing a simplified model of the aircraft propulsion system according to the frequency range to obtain a mesh of the aircraft propulsion system model; assigning materials to each mesh in the mesh of the aircraft propulsion system model to obtain a mesh of the aircraft propulsion system model with material properties; setting measuring points in the mesh of the aircraft propulsion system model with material properties according to the installation positions of airborne electronic equipment; setting a HIRF electromagnetic excitation with a preset electric field strength; and obtaining the induced electric field strength of the measuring points under the HIRF electromagnetic excitation.

[0006] Optionally, assigning material to each grid in the aircraft propulsion system whole machine model grid includes: adding a material parameter to each grid, and the material parameter includes material conductivity and material thickness.

[0007] Optionally, setting the HIRF electromagnetic excitation of a preset electric field strength includes setting an incident angle and a polarization direction of a plane wave.

[0008] Optionally, the preset electric field strength is 1 volt / meter.

[0009] Optionally, the method further includes: simplifying the engine three-dimensional model and the nacelle three-dimensional model according to the electromagnetic protection design document to obtain a simplified engine model and a simplified nacelle model; integrating the simplified engine model and the simplified nacelle model into a simplified model of the aircraft propulsion system as a whole, wherein the simplified model of the aircraft propulsion system as a whole retains the electrical connection relationship between the engine and the nacelle.

[0010] Optionally, simplifying the engine three-dimensional model and the nacelle three-dimensional model according to the electromagnetic protection design document includes: deleting mechanical structures irrelevant to electromagnetic protection in the engine three-dimensional model and the nacelle three-dimensional model according to the electromagnetic protection design document.

[0011] Optionally, the mechanical structure not related to electromagnetic protection includes bolts, mounting holes and rivets.

[0012] Optionally, it also includes determining whether the ratio of the induced electric field strength to the preset electric field strength is lower than a preset threshold value; if not, optimizing the electromagnetic protection design of the entire aircraft propulsion system according to the induced electric field strength of the measuring point.

[0013] Optionally, optimizing the electromagnetic protection design of the entire aircraft propulsion system according to the induced electric field strength of the measuring point includes changing the installation position of the onboard electronic equipment.

[0014] Optionally, optimizing the electromagnetic protection design of the entire aircraft propulsion system according to the induced electric field strength at the observation point includes optimizing the nacelle three-dimensional model.

[0015] Optionally, the frequency range of the electromagnetic environment is 100 MHz to 6 GHz.

[0016] Compared with the prior art, the present invention has the following advantages:

[0017] The method for obtaining the HIRF induction field inside the aircraft propulsion system proposed in the present invention, on the one hand, is based on the three-dimensional simulation model of the aircraft propulsion system as a whole machine instead of experimental calculation of the electromagnetic induction field strength of the installation position of the internal airborne electronic equipment of the aircraft propulsion system as a whole machine under electromagnetic environments of different frequencies, and can obtain the electromagnetic protection weaknesses and design points to be optimized of the current aircraft propulsion system design according to the overall configuration of the aircraft propulsion system, effectively preventing the electromagnetic protection from being under-designed and over-designed in the design stage, thereby reducing the electromagnetic protection design cost; on the other hand, the simplified model of the aircraft propulsion system as a whole machine is meshed according to the determined HIRF electromagnetic environment frequency range to be analyzed, fully considering the induction field differences caused by different electromagnetic coupling mechanisms under different electromagnetic environment frequency ranges, and can use the minimum number of meshes that meet the simulation accuracy to solve and calculate the electromagnetic field strength of the internal measuring points of the aircraft propulsion system as a whole machine, thereby reducing the electromagnetic protection design cost; in addition, the present invention uses a plane wave instead of a transmitting antenna as the HIRF electromagnetic excitation, omitting the modeling process of the electromagnetic excitation transmitting antenna corresponding to different HIRF frequency ranges, saving the simulation modeling cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The accompanying drawings are included to provide a further understanding of the present application. They are included and constitute a part of the present application. The accompanying drawings illustrate embodiments of the present application and together with the present specification serve to explain the principles of the present invention. In the accompanying drawings:

[0019] Figure 1 is a flow chart of a method for acquiring a HIRF induction field inside an aircraft propulsion system according to an embodiment of the present invention.

[0020] Figure 2 It is a flow chart for constructing a simplified model of the entire aircraft propulsion system.

[0021] Figure 3 It is a schematic diagram of a simplified model of a propulsion system according to an embodiment of the present invention.

[0022] Figure 4 It corresponds to Figure 3 Schematic diagram of the grid of the propulsion system model.

[0023] Figure 5 It is a schematic diagram of a mesh of an aircraft propulsion system model with material properties according to an embodiment of the present invention.

[0024] Figure 6 A schematic diagram of a method for acquiring the HIRF induction field inside an aircraft propulsion system.

[0025] Figure 7 yes Figure 1 A flow chart of a method for obtaining a HIRF induction field inside an aircraft propulsion system according to an optimized embodiment. DETAILED DESCRIPTION

[0026] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following is a brief introduction to the drawings required for the description of the embodiments. Obviously, the drawings described below are only some examples or embodiments of the present application. For ordinary technicians in this field, the present application can also be applied to other similar scenarios based on these drawings without creative work. Unless it is obvious from the language environment or otherwise explained, the same reference numerals in the figures represent the same structure or operation.

[0027] Flowcharts are used in the present application to illustrate the operations performed by the system according to the embodiments of the present application. It should be understood that the preceding or following operations are not necessarily performed accurately in order. On the contrary, various steps may be processed in reverse order or simultaneously. At the same time, other operations may be added to these processes, or one or more operations may be removed from these processes.

[0028] Figure 1 FIG. 1 is a flow chart of a method for obtaining a HIRF induction field inside an aircraft propulsion system according to an embodiment of the present invention. Figure 1 As shown, the method 100 for obtaining the HIRF induction field inside the aircraft propulsion system includes the following steps:

[0029] Step S11: Acquire the frequency range of the electromagnetic environment.

[0030] Optionally, the frequency range of the electromagnetic environment is 100 MHz to 6 GHz.

[0031] Step S12: meshing the simplified model of the aircraft propulsion system according to the frequency range to obtain a mesh of the aircraft propulsion system model.

[0032] Optionally, before entering step S12, step S120 is also included: constructing a simplified model of the entire aircraft propulsion system. Figure 2 It is a flow chart for constructing a simplified model of the entire aircraft propulsion system. Figure 3 Schematic diagram of a simplified model of a propulsion system according to an embodiment of the present invention. Figure 2 As shown in the figure, constructing a simplified model of the aircraft propulsion system includes:

[0033] Step S1201: Simplify the engine three-dimensional model and the nacelle three-dimensional model according to the electromagnetic protection design document to obtain the simplified engine model and the simplified nacelle model. Optionally, simplifying the engine three-dimensional model and the nacelle three-dimensional model according to the electromagnetic protection design document includes deleting mechanical structures in the engine three-dimensional model and the nacelle three-dimensional model that are not related to electromagnetic protection. Mechanical structures that are not related to electromagnetic protection include but are not limited to bolts, mounting holes, and rivets. In some embodiments, simplifying the engine three-dimensional model and the nacelle three-dimensional model according to the electromagnetic protection design document also includes deleting chamfering process parameters in the engine three-dimensional model and the nacelle three-dimensional model. Because whether the mechanical structure in the model is a right angle or a chamfer does not affect the electromagnetic protection. However, chamfering will increase the complexity of the model, reduce the efficiency of simulation calculations, and thus increase the cost of electromagnetic protection design.

[0034] Step S1202: Integrate the simplified engine model and the simplified nacelle model into a simplified model of the aircraft propulsion system. The simplified model of the aircraft propulsion system retains the electrical connection relationship between the engine and the nacelle. Figure 3 As shown, the simplified model 300 of the aircraft propulsion system includes a simplified engine model (not shown) and a simplified nacelle model 31. The simplified nacelle model 31 covers the simplified engine model. The simplified nacelle model 31 includes an air intake fairing 311, a fan cover 312, a reverse thrust device 313 and a tail nozzle 314. The simplified nacelle model 31 ensures that the engine can work normally in various use environments and flight conditions, and converts the thrust of the engine into the power of the aircraft to achieve operations such as propulsion and steering in the air.

[0035] In step S12, optionally, HFSS (High Frequency Simulator Structure) software is used to discretize the simplified model of the aircraft propulsion system into individual units (tetrahedral meshes), and then the field value on each unit is calculated respectively, so as to deduce the electromagnetic field characteristics of the entire model. HFSS software is developed by Ansoft Corporation of the United States. HFSS software uses the finite element method (FEM) to analyze the electromagnetic characteristics of three-dimensional objects. The basic process of solving the problem by the finite element method includes three parts: discretization of the analysis object, finite element solution and processing of the calculation results. Figure 4 It corresponds to Figure 3 The grid diagram of the propulsion system model is shown in Figure 1. Figure 4 As shown, the propulsion system complete machine model grid 400 is obtained by meshing the propulsion system complete machine simplified model 300. Step S13: assigning materials to each grid in the aircraft propulsion system complete machine model grid to obtain the aircraft propulsion system complete machine model grid with material attributes. Figure 55 is a schematic diagram of a grid of an aircraft propulsion system model with material attributes according to an embodiment of the present invention. Different structures in the grid 500 of the aircraft propulsion system model with material attributes use different materials. For example, the fan cover 512 and the thrust reverser 513 have different material attributes.

[0036] Optionally, assigning material to each mesh in the aircraft propulsion system model mesh includes: adding a material parameter to each mesh, the material parameter including but not limited to material conductivity and material thickness.

[0037] Step S14: In the aircraft propulsion system model grid with material attributes, measurement points are set according to the installation positions of the onboard electronic equipment.

[0038] For example, a measuring point is set in the grid occupied by electronic device A, and a measuring point is set in the grid occupied by communication cable B.

[0039] Step S15: Setting a HIRF electromagnetic excitation with a preset electric field strength.

[0040] Preferably, a plane wave is used instead of a transmitting antenna as the HIRF electromagnetic excitation, so that the modeling process of the electromagnetic excitation transmitting antenna corresponding to different HIRF frequency ranges can be omitted. The HIRF electromagnetic excitation with a preset electric field strength set by a plane wave includes setting plane wave attribute parameters, and the plane wave attribute parameters include but are not limited to the incident angle and the polarization direction. A plane wave means that both the electric field and the magnetic field of the electromagnetic wave can be analyzed in one plane. Analyzing a plane wave is an analysis method that simplifies a 3D wave into a 2D wave, and this method can characterize the characteristics of the electromagnetic wave.

[0041] Preferably, the preset electric field strength of the HIRF electromagnetic excitation is set to 1 volt / meter, so that the normalization process in the data post-processing can be omitted. The above can be understood as not needing to calculate the ratio of the induced electric field strength of the measuring point to the preset electric field strength. Since the preset electric field strength is 1, the induced electric field strength of the measuring point / the preset electric field strength=the induced electric field strength of the measuring point. If the preset electric field strength is not 1, for example, the preset electric field strength is 100 volts / meter, the value of the induced electric field strength of the measuring point needs to be divided by 100 to obtain the final value.

[0042] Step S16: Obtain the induced electric field strength of the measuring point under HIRF electromagnetic excitation.

[0043] Taking the measuring point at the position of electronic device A as an example, the field value on each grid in the grid occupied by electronic device A is calculated, and the field value is averaged to calculate the induced electric field strength of the measuring point at the position of electronic device A.

[0044] Figure 6 A schematic diagram of a method for obtaining the HIRF induction field inside an aircraft propulsion system. Figure 6 As shown, the aircraft propulsion system grid 500 with material attributes is placed under a plane wave P electromagnetic excitation with an electric field strength of 1 V / m, and the electromagnetic induction field strength at a specified measuring point is obtained by simulation calculation. The plane wave attribute parameters (such as the plane wave incident angle and polarization direction) are adjusted to obtain the electromagnetic induction field strength at the measuring point under different electromagnetic excitation settings.

[0045] The method for obtaining the HIRF induction field inside the aircraft propulsion system proposed in the present invention, on the one hand, is based on a three-dimensional simulation model of the aircraft propulsion system as a whole machine instead of experimentally calculating the electromagnetic induction field strength of the installation position of the internal airborne electronic equipment of the aircraft propulsion system as a whole machine under electromagnetic environments of different frequencies, and can obtain the electromagnetic protection weaknesses and design points to be optimized of the current aircraft propulsion system as a whole machine design according to the overall configuration of the aircraft propulsion system, and effectively prevent electromagnetic protection under-design and over-design in the design stage, thereby reducing the electromagnetic protection design cost; on the other hand, the simplified model of the aircraft propulsion system as a whole machine is meshed according to the determined HIRF electromagnetic environment frequency range to be analyzed, and the induction field difference caused by the different electromagnetic coupling mechanisms under different electromagnetic environment frequency ranges is fully considered, and the electromagnetic field strength of the internal measuring points of the aircraft propulsion system as a whole machine can be solved and calculated using the minimum number of grids that meet the simulation accuracy, thereby reducing the electromagnetic protection design cost.

[0046] Figure 7 yes Figure 1 Flow chart of the method for obtaining the internal HIRF induction field of the aircraft propulsion system in the optimized embodiment. Figure 7 As shown, the method 700 for obtaining the HIRF induction field inside the aircraft propulsion system also includes:

[0047] Step S17: determine whether the ratio of the induced electric field strength to the preset electric field strength is lower than a preset threshold value, if yes, then end; if no, proceed to step S18;

[0048] Step S18: Optimizing the electromagnetic protection design of the aircraft propulsion system according to the induced electric field strength of the measuring point.

[0049] Optionally, if the ratio of the induced electric field strength to the preset electric field strength is higher than a preset threshold, the installation position of the onboard electronic equipment is changed or the nacelle three-dimensional model is optimized according to the induced electric field strength. In other words, when the induced electric field strength at the measuring point does not meet the electromagnetic protection requirements, the current simplified model of the aircraft propulsion system needs to be optimized.

[0050] Step S19: recalculate the induced electric field strength at the measuring point according to the optimized electromagnetic protection design of the aircraft propulsion system. In other words, after step S19, proceed to steps S11 to S17. The whole process is an iterative process, and stops when the ratio of the induced electric field strength to the preset electric field strength is lower than the preset threshold.

[0051] The basic concepts have been described above. Obviously, for those skilled in the art, the above invention disclosure is only used as an example and does not constitute a limitation of the present application. Although not explicitly stated herein, those skilled in the art may make various modifications, improvements and amendments to the present application. Such modifications, improvements and amendments are suggested in the present application, so such modifications, improvements and amendments still belong to the spirit and scope of the exemplary embodiments of the present application.

[0052] At the same time, the present application uses specific words to describe the embodiments of the present application. For example, "one embodiment", "an embodiment", and / or "some embodiments" refer to a certain feature, structure or characteristic related to at least one embodiment of the present application. Therefore, it should be emphasized and noted that "one embodiment" or "an embodiment" or "an alternative embodiment" mentioned twice or more in different positions in this specification does not necessarily refer to the same embodiment. In addition, some features, structures or characteristics in one or more embodiments of the present application can be appropriately combined.

[0053] Similarly, it should be noted that in order to simplify the description of the disclosure of this application and thus help understand one or more embodiments of the invention, in the above description of the embodiments of this application, multiple features are sometimes combined into one embodiment, figure or description thereof. However, this disclosure method does not mean that the features required by the object of this application are more than the features mentioned in the claims. In fact, the features of the embodiments are less than all the features of the single embodiment disclosed above.

[0054] In some embodiments, numbers describing the number of components and attributes are used. It should be understood that such numbers used in the description of the embodiments are modified by the modifiers "about", "approximately" or "substantially" in some examples. Unless otherwise specified, "about", "approximately" or "substantially" indicate that the numbers are allowed to vary by ±20%. Accordingly, in some embodiments, the numerical parameters used in the specification and claims are approximate values, which may change according to the required features of individual embodiments. In some embodiments, the numerical parameters should take into account the specified significant digits and adopt the general method of retaining digits. Although the numerical domains and parameters used to confirm the breadth of their range in some embodiments of the present application are approximate values, in specific embodiments, the setting of such numerical values ​​is as accurate as possible within the feasible range.

[0055] As shown in this application and claims, unless the context clearly indicates an exception, the words "a", "an", "an" and / or "the" do not refer to the singular and may also include the plural. Generally speaking, the terms "include" and "comprise" only indicate the inclusion of the steps and elements that have been clearly identified, and these steps and elements do not constitute an exclusive list. The method or device may also include other steps or elements.

[0056] Unless otherwise specifically stated, the relative arrangement, numerical expressions and numerical values ​​of the parts and steps set forth in these embodiments do not limit the scope of the present application. At the same time, it should be understood that, for ease of description, the sizes of the various parts shown in the accompanying drawings are not drawn according to the actual proportional relationship. The technology, method and equipment known to those of ordinary skill in the relevant field may not be discussed in detail, but in appropriate cases, the technology, method and equipment should be considered as a part of the authorization specification. In all examples shown and discussed here, any specific value should be interpreted as being merely exemplary, rather than as a limitation. Therefore, other examples of exemplary embodiments may have different values. It should be noted that similar reference numerals and letters represent similar items in the following drawings, so that once a certain item is defined in an accompanying drawing, it does not need to be further discussed in subsequent drawings.

[0057] Although the present application has been described with reference to the current specific embodiments, ordinary technicians in this technical field should recognize that the above embodiments are only used to illustrate the present application, and various equivalent changes or substitutions may be made without departing from the spirit of the present application. Therefore, as long as the changes and modifications to the above embodiments are within the essential spirit of the present application, they will fall within the scope of the claims of the present application.

Claims

1. A method for obtaining a HIRF induction field inside an aircraft propulsion system, characterized in that: include: Obtain the frequency range of the electromagnetic environment; Meshing the simplified model of the aircraft propulsion system according to the frequency range to obtain a mesh of the aircraft propulsion system model; Assigning material to each grid in the aircraft propulsion system whole machine model grid to obtain the aircraft propulsion system whole machine model grid with material attributes; In the aircraft propulsion system whole machine model grid with material attributes, measuring points are set according to the installation positions of the airborne electronic equipment; Setting HIRF electromagnetic excitation with a preset electric field strength; The induced electric field strength of the measuring point under the HIRF electromagnetic excitation is obtained.

2. The method according to claim 1, characterized in that Assigning material to each grid in the aircraft propulsion system model grid includes: adding a material parameter to each grid, and the material parameter includes material conductivity and material thickness.

3. The method according to claim 1, characterized in that Setting the HIRF electromagnetic excitation of a preset electric field strength includes setting the incident angle and polarization direction of the plane wave.

4. The method according to claim 3, characterized in that The preset electric field strength is 1 volt / meter.

5. The method according to claim 1, characterized in that Also includes: Simplify the engine 3D model and the nacelle 3D model according to the electromagnetic protection design document to obtain the engine simplified model and the nacelle simplified model; The simplified engine model and the simplified nacelle model are integrated into the simplified model of the aircraft propulsion system as a whole, and the simplified model of the aircraft propulsion system as a whole retains the electrical connection relationship between the engine and the nacelle.

6. The method according to claim 5, characterized in that Simplified engine 3D model and nacelle 3D model according to electromagnetic protection design documents include: Mechanical structures irrelevant to electromagnetic protection in the engine three-dimensional model and the nacelle three-dimensional model are deleted according to the electromagnetic protection design document.

7. The method according to claim 6, characterized in that Mechanical structures not related to electromagnetic protection include bolts, mounting holes and rivets.

8. The method according to claim 5, characterized in that The method also includes determining whether the ratio of the induced electric field strength to the preset electric field strength is lower than a preset threshold value. If not, optimizing the electromagnetic protection design of the entire aircraft propulsion system according to the induced electric field strength of the measuring point.

9. The method according to claim 8, characterized in that Optimizing the electromagnetic protection design of the aircraft propulsion system according to the induced electric field strength of the measuring point includes: changing the installation position of the airborne electronic equipment according to the induced electric field strength of the measuring point.

10. The method according to claim 8, characterized in that Optimizing the electromagnetic protection design of the aircraft propulsion system according to the induced electric field strength of the measuring points includes: optimizing the nacelle three-dimensional model according to the induced electric field strength of the measuring points.

11. The method according to any one of claims 1 to 10, characterized in that: The frequency range of the electromagnetic environment is 100 MHz to 6 GHz.

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