Simulation method for evaluating radiation influence of airborne high-power microwave generator on platform equipment

Abstract

The invention discloses a simulation method for evaluating radiation influence of an airborne high-power microwave generator on platform equipment. The method comprises the following steps: designing an equivalent model of the generator; the simulation model is preprocessed; performing equivalent treatment on the material of each part of the fuselage; triangular grids are generated through surface subdivision, and the size and the number of the grids are determined according to the calculation frequency band; electromagnetic simulation software and an algorithm are selected; selecting an electric field frequency for simulation aiming at a complete machine electric field, and performing simulation analysis on complete machine magnetic field distribution aiming at a complete machine magnetic field; and comprehensively drawing conclusions for the whole machine electric field and the whole machine magnetic field. According to the invention, a protection basis and technical support can be provided for reliable application of the unmanned helicopter platform in a high-power microwave environment, and meanwhile, development of a compatibility design technology of an HPM system is promoted.

Description

Technical Field

[0001] The present invention relates to the field of unmanned aerial vehicles, and in particular to a simulation method for evaluating the radiation effect of an airborne high-power microwave generator on platform equipment. Background Art

[0002] As a new type of directed energy device, high-power microwave (HPM) technology is widely used in airborne platforms such as unmanned helicopters for electromagnetic strikes on remote targets. However, the HPM payload generator will generate strong electromagnetic leakage during operation, which may interfere with other devices on the platform and even affect the performance or safety of key electronic devices. Existing research mainly focuses on the impact of HPM on the overall electromagnetic environment, but there is less quantitative analysis of the radiation intensity received by devices at different positions inside the airborne platform, making it difficult to meet the protection design requirements in the complex electromagnetic environment of the platform.

[0003] The existing technology has limitations in evaluating the radiation effect of HPM payload leakage, lacking the analysis of the comprehensive influence of device position, shielding effect, and frequency change, resulting in a lack of pertinence in device protection design and reducing the reliability and safety of the platform in the complex electromagnetic environment. Summary of the Invention

[0004] Object of the Invention: To overcome the deficiencies of the background art, the present invention discloses a simulation method for evaluating the radiation effect of an airborne high-power microwave generator on platform equipment. By establishing an equivalent model of an unmanned helicopter platform and an HPM payload generator, and combining the method of moments and fine material processing, this method simulates the distribution characteristics of the electric and magnetic fields of the generator at different frequencies and evaluates the radiation intensity of the equipment in each area of the platform.

[0005] Technical Solution: The simulation method for evaluating the radiation effect of an airborne high-power microwave generator on platform equipment disclosed by the present invention includes the following steps:

[0006] S1. Design the equivalent model of the generator;

[0007] S2. Preprocess the simulation model, divide the positions on the airborne platform where the generator can be installed into regions, and divide the interior into compartments;

[0008] S3. According to the material setting function of the simulation software, perform equivalent processing on the materials of each part of the fuselage;

[0009] S4. Generate triangular meshes through surface meshing, and determine the size and number of meshes according to the calculation frequency band;

[0010] S5. Based on the simulation frequency and type, select the electromagnetic simulation software and algorithm;

[0011] S6. For the overall machine's electric field, select the electric field frequency for simulation. For the overall machine's magnetic field, simulate and analyze the distribution of the overall machine's magnetic field.

[0012] S7. For the overall machine's electric field and magnetic field respectively, analyze the ranking of the electric field / magnetic field intensity distribution at the middle positions in each region from large to small, and draw a conclusion.

[0013] Among them, the equivalent model of the generator in S1 includes the design of the equivalent model of the generator's magnetic field source and the design of the equivalent model of the generator's electric field.

[0014] For the design of the equivalent model of the generator's magnetic field source, design a spiral coil to simulate the magnetic field generated by the HPM source, and compare the simulation results and test results of the magnetic field distribution around the generator to ensure that the error is within 1 dB.

[0015] For the design of the equivalent model of the generator's electric field, combined with the working principle of the high-power microwave payload, construct a generator model, retaining the main metal structures and main electrical connection parts of the generator. The model includes the primary energy source, MARX generator, horn antenna, spiral coil, metal floor and ground wire. The gas switch is located inside the MARX generator, and the thyristor switch is located inside the primary energy source. At the same time, test and analyze the frequency range where the electric field frequency radiated by the generator mainly concentrates.

[0016] Furthermore, in S2, use CATIA software to model the airborne platform based on the scaled model of the unmanned helicopter, retaining the aerodynamic shape of the helicopter (cabin body, rotor, tower, tail, landing gear, optoelectronic pod and one-dimensional mechanical scanning radar), and simplify the internal structure. When simulating, take the axis direction of the helicopter (the forward direction of the helicopter) as the Y-axis, the height direction of the helicopter as the Z-axis direction, and the width direction as the X-axis direction. The positions on the airborne platform for installing antennas are divided into six major regions, defined as Region 1 to Region 6, and the inside is divided into six compartments, defined as Compartment A to Compartment F.

[0017] Furthermore, in S3, according to the material setting function of the FEKO simulation software, define including: the material, equivalent conductivity, thickness of the fuselage region; the materials of the optoelectronic pod, landing gear, and one-dimensional mechanical scanning radar; the materials of the tower and landing gear; the frequency.

[0018] Furthermore, in S4, three-dimensional electromagnetic numerical simulation is adopted.

[0019] Furthermore, in S5, select the commercial electromagnetic simulation software FEKO and use the method of moments for simulation.

[0020] Furthermore, in S6, for the overall machine's electric field, select the electric field frequency that has a greater impact on the platform for simulation. For the overall machine's magnetic field, place the equivalent model of the generator's magnetic field source at the generator position and simulate and analyze the distribution of the overall machine's magnetic field.

[0021] The main results include the electric field / magnetic field distributions in Compartment A, Compartment B, Compartment C, Compartment D, Compartment E, Compartment F, the electric field / magnetic field distributions in Region 1, Region 2, Region 3, Region 4, the electric field / magnetic field distributions in Region 5 (at the two-dimensional phased array radar), and the electric field / magnetic field distributions in Region 6 (at the optoelectronic pod position).

[0022] Beneficial effects: Compared with the prior art, the advantages of the present invention are as follows:

[0023] By establishing an equivalent model of an unmanned helicopter platform and a high-power microwave (HPM) payload generator, and using the simulation software FEKO to accurately simulate the electric and magnetic field distribution characteristics at different frequencies, the problem of incomplete evaluation of electromagnetic interference in complex platforms is solved;

[0024] It can clarify the radiation intensity distribution of equipment in various regions inside and outside the platform, provide a scientific basis for the electromagnetic protection design of key equipment, and improve its stability and reliability in a high-power microwave environment;

[0025] It also provides technical support for the compatibility evaluation and safety design of the HPM system, and has important application value. Description of the Drawings

[0026] Figure 1 is the flowchart of the method of the present invention;

[0027] Figure 2 is the schematic diagram of the high-power payload of the present invention;

[0028] Figure 3 is the distribution diagram of the measurement points for the numerical test of electromagnetic radiation of the present invention;

[0029] Figure 4 is the simulation model diagram of the electric field equivalent source of the present invention;

[0030] Figure 5 is the simulation model diagram of the magnetic field equivalent source of the present invention;

[0031] Figure 6 is the schematic diagram of the partition of the airborne platform of the present invention. Detailed Embodiments

[0032] The technical solution of the present invention will be further described below in conjunction with the drawings and embodiments. [[ID=4?]]

[0033] The present invention provides a simulation method for evaluating the radiation effect of an airborne high-power microwave generator on platform equipment, as Figure 1 shown, which specifically includes the following steps:

[0034] Step 1: Design the equivalent model of the generator;

[0035] In this embodiment, the high-power microwave (HPM) payload consists of two parts: a generator and an antenna. The generator consists of a primary energy source and a Marx generator. Through theoretical analysis of the electromagnetic radiation mechanism during the operation of the high-power microwave payload, switches (thyristor switches, high-voltage pulse triggers, and gas switches) are the main electric field radiation sources. The pulsed transient current generated when the switches conduct will generate electromagnetic radiation, and the gas switch is the main radiation source. The schematic diagram of the high-power payload is as Figure 2 shown.

[0036] In this embodiment, the electromagnetic radiation value of the generator is tested in the microwave anechoic chamber hall. An electric field antenna is used to monitor the electric field radiation value during the discharge process of the generator. The distribution diagram of the measurement points is as Figure 3 shown. In the figure, 15 measurement points are used to complete this test. Along the central axis of the HPM payload coaxial, A1, B1, C1, D1, and E1 are distributed 1 m apart, with an actual ground clearance of 1.7 m; A2, B2, C2, D2, and E2 are located 0.5 m in the +Y axis direction of A1, B1, C1, D1, and E1, with an actual ground clearance of 2.2 m; A3, B3, C3, D3, and E3 are located 0.5 m in the -Y axis direction of A1, B1, C1, D1, and E1, with an actual ground clearance of 1.2 m, for a total of 15 measurement points. Each measurement point has 3 polarizations for the antenna arrangement, namely polarization in the X-axis direction, polarization in the Y-axis direction, and polarization in the Z-axis direction. The test results are shown in Table 1.

[0037] Table 1 Test results of each measurement point

[0038]

[0039]

[0040] In this test, the electric field values in 3 polarization directions at 3 different heights in 5 positions are measured, for a total of 45 groups of test data. The frequencies monitored by the electric field antenna are relatively dispersed, distributed in the range of 25 MHz to 156 MHz. Among them, the frequency range of 25 MHz to 35 MHz appears 16 times, the frequency range of 35 MHz to 45 MHz appears 15 times, and other frequency points appear 14 times. The frequency band of 25 MHz to 45 MHz covers 69% of the test data. Therefore, the electric field frequencies radiated by the generator are mainly concentrated around 30 MHz and 40 MHz.

[0041] For the simulation design of the electric field equivalent source, combined with the working principle of the high-power microwave payload, a generator model is constructed, retaining the main metal structure and the main electrical connection parts of the generator. The generator simulation model is as Figure 4As shown in the figure. The model mainly includes primary energy, a MARX generator, a horn antenna, a spiral coil, a metal floor, and a ground wire. The gas switch is located inside the MARX generator, and the thyristor switch is located inside the primary energy.

[0042] The electric field radiated by the high-power microwave payload at 30 MHz is mainly generated by the thyristor switch. An excitation source is applied at the position of the Figure 4 thyristor switch to simulate and analyze the electric field distribution of the high-power microwave payload at 30 MHz. The electric field radiated by the high-power microwave payload at 40 MHz is mainly generated by the gas switch. An excitation source is applied at the position of the Figure 4 gas switch to simulate and analyze the electric field distribution of the high-power microwave payload at 40 MHz. The simulation results at 30 MHz and 40 MHz are compared with the test results, and the results are shown in Table 2.

[0043] Table 2 Comparison Table of Simulation Results and Test Results at 30 MHz and 40 MHz

[0044]

[0045]

[0046] The analysis of the comparison results is as follows:

[0047] The numerical values of 3 polarization directions at 15 measurement points in the simulation (test) are a total of 45 groups of test data.

[0048] (1) The frequency band of 25 MHz - 35 MHz contains 16 groups of test data. When compared with the simulation results at a frequency of 30 MHz, 10 groups have a difference of less than 3 dB;

[0049] (2) It appears 15 times in the frequency band of 35 MHz - 45 MHz. When compared with the simulation results at a frequency of 40 MHz, 9 groups have a difference of less than 3 dB.

[0050] The simulation results can basically fit the test results, but the fitting rate is not high, mainly due to the following reasons:

[0051] (1) The generator in the test state is not assembled completely. Each part is relatively scattered, there are many exposed connection cables, and there are a certain number of metal structures around the generator;

[0052] (2) The frequency points captured during the test are relatively scattered, with a certain deviation from the simulation frequency.

[0053] Improvement measures: After the generator is assembled completely, obtain detailed dimension data and test (simulate) the electromagnetic radiation numerical values of the generator in the complete state.

[0054] For the simulation design of the magnetic field equivalent source, design a spiral coil to simulate the magnetic field generated by the HPM source. The equivalent model of the generator is asFigure 5 As shown in the figure, the comparison table of the magnetic field distribution simulation results and the test results is shown in Table 3. Comparing the simulation results and the test results of the magnetic field distribution around the generator, the error is within 1 dB.

[0055] Table 3 Comparison Table of Magnetic Field Distribution Simulation Results and Test Results

[0056] Position Simulation value / mT Test value / mT Error / dB F1 3.275 3.566 -0.37 G1 3.221 3.906 -0.84 H1 1.615 1.477 0.39 L1 3.734 3.996 -0.29 J1 6.969 6.793 0.11

[0057] Step 2: Preprocess the simulation model. The simulation object is a scaled model of an unmanned helicopter. Use CATIA software to model the scaled model, and divide the positions on the airborne platform where the generator can be installed into six major regions, and divide the interior into six compartments;

[0058] In this embodiment, the object involved in the simulation is a certain type of unmanned helicopter, and the simulation object is a scaled model of this type of helicopter. The size of the helicopter is about 10.3m * 8.3m * 3m. Use CATIA software to model the airborne platform. To ensure the accuracy and speed of the calculation, retain the aerodynamic shape of the helicopter (the main body of the cabin, the rotor, the tower, the tail, the landing gear, the electro-optical pod, and the one-dimensional mechanical scanning radar), and simplify the internal structure. During the simulation, the axis direction of the helicopter (the forward direction of the helicopter) is used as the Y-axis, the height direction of the helicopter is used as the Z-axis direction, and the width direction is used as the X-axis direction. The positions on the airborne platform for installing the antenna can be divided into six major regions, defined as Region 1 to Region 6, and the interior is divided into six compartments, defined as Compartment A to Compartment F. The schematic diagram of the airborne platform partition is as Figure 6 shown, and the size table of the simulation area division is shown in Table 4.

[0059] Table 4 Size Table of Simulation Area Division

[0060]

[0061]

[0062] Step 3: According to the material setting function of the FEKO simulation software, perform equivalent processing on the materials of each part of the fuselage;

[0063] In this embodiment, the main material of the helicopter fuselage is a composite material covered with a copper mesh, and the electro-optical pod, the one-dimensional mechanical scanning radar, and the landing gear are made of metal materials. According to the material setting function of the FEKO simulation software, perform equivalent processing on the materials of each part of the fuselage, and the definitions are as follows: Fuselage area: lossy metal, equivalent conductivity 5.2E6, thickness 0.2mm; Electro-optical pod, landing gear, one-dimensional mechanical scanning radar: PEC; Tower, landing gear: fiberglass; Frequency: 20 MHz to 200 MHz.

[0064] Step 4: Generate triangular meshes through surface meshing, and determine the size and number of meshes according to the calculation frequency band;

[0065] In this embodiment, all are three-dimensional electromagnetic numerical simulations. A triangular network is generated through surface meshing, and the size of the grid is determined according to the calculation frequency band. For the grid model at the 40 MHz frequency point, the number of grids is approximately 80,000.

[0066] Step 5: Based on the simulation frequency, select the commercial electromagnetic simulation software FEKO and perform the simulation using the method of moments.

[0067] In this embodiment, the calculation object is a rotorcraft. When simulating the magnetic field effect of a high-power microwave antenna, the frequency is 20 MHz to 200 MHz. The commercial electromagnetic simulation software FEKO is selected and the method of moments is used.

[0068] Step 6: For the electric field of the whole machine, simulate the electric fields at 30 MHz and 40 MHz respectively. For the magnetic field of the whole machine, place the equivalent model of the generator magnetic field source at the generator position and simulate and analyze the magnetic field distribution of the whole machine.

[0069] (1) For simulating the electric field of the generator, place the equivalent model of the generator electric field source at the generator position, add an excitation source at the thyristor position, and simulate and analyze the electric field distribution of the whole machine at 30 MHz.

[0070] Electric field distribution in Cabin A (electric field at 30 MHz): The electric field value ranges from -16 to 20 dBW / m2 at a distance of 20 mm from the bottom metal plate, and the values in most areas are between -5 and 10; the electric field value ranges from -25 to 20 dBW / m2 at a distance of 120 mm from the bottom metal plate, and the values in most areas are between -15 and 0; the electric field value ranges from -20 to 30 dBW / m2 at a distance of 220 mm from the bottom metal plate; the electric field power density is relatively large in the area closer to the generator, with values between 10 and 30, and the values in other areas are relatively small, mainly concentrated between -20 and 10.

[0071] Analysis of simulation results: The electric field is stronger when closer to the equivalent source, and the maximum value flashes to 30 dBW / m2; the electric field power density values in other areas are mainly concentrated between -15 and 10 dBW / m2.

[0072] Electric field distribution in Cabin B (electric field at 30 MHz): The electric field value ranges from -8 to 28 dBW / m2 at a distance of 20 mm from the bottom metal plate, and the values in most areas are between 10 and 25 dBW / m2; the electric field value ranges from -8 to 24 dBW / m2 at a distance of 120 mm from the bottom metal plate; the electric field value ranges from -7 to 60 dBW / m2 at a distance of 220 mm from the bottom metal plate; the electric field power density is relatively large in the area closer to the generator, with values between 30 and 60 dBW / m2, and the values in other areas are relatively small, mainly concentrated between 5 and 30 dBW / m2.

[0073] Analysis of simulation results: When the distance is relatively close to the equivalent source, the electric field is stronger, and the maximum value reaches 60 dBW / m2; the numerical values of the electric field power density in other regions are mainly concentrated between 5 and 30 dBW / m2.

[0074] Electric field distribution in Cabin C (electric field at 30 MHz): The numerical range of the electric field at 20 mm from the bottom metal plate is -7.5 to 15 dBW / m2, and the numerical values in most regions are between 0 and 10 dBW / m2; the numerical range of the electric field at 320 mm from the bottom metal plate is -27 to 3 dBW / m2; the numerical range of the electric field at 720 mm from the bottom metal plate is -24 to 6 dBW / m2; the numerical values in most regions are between -15 and 0 dBW / m2.

[0075] Analysis of simulation results: The electric field intensity in the bottom area of Cabin C (20 m from the bottom metal plate) is relatively large, and the electric field intensity in the middle and upper areas is relatively small.

[0076] Electric field distribution in Cabin D (electric field at 30 MHz): The numerical range of the electric field at 120 mm from the bottom metal plate is -32 to 4 dBW / m2, and the numerical values in most regions are between -20 and -5 dBW / m2; the numerical range of the electric field at 320 mm from the bottom metal plate is -30 to 0 dBW / m2, and the numerical values in most regions are between -20 and -10 dBW / m2; the numerical range of the electric field at 720 mm from the bottom metal plate is -30 to -3 dBW / m2; the numerical values in most regions are between -20 and -10 dBW / m2;

[0077] Analysis of simulation results: The electric field intensity in the bottom area of Cabin D is relatively small, and the numerical values of the electric field in most regions are between -20 and -5 dBW / m2. There are local areas with relatively large electric field intensity at the edge, and the maximum value reaches 4 dBW / m2.

[0078] Electric field distribution in Cabin E (electric field at 30 MHz): The numerical range of the electric field at 420 mm from the bottom metal plate is -24 to 12 dBW / m2; the numerical range of the electric field at 720 mm from the bottom metal plate is -24 to 30 dBW / m2; the numerical values in most regions are between -20 and 0 dBW / m2; there are local areas (near the aircraft skin) with relatively large electric field numerical values, and the maximum value is 30 dBW / m2.

[0079] Analysis of simulation results: The electric field intensity in the bottom area of Cabin E is relatively small, and the electric field numerical values in the local areas at the edge are relatively large.

[0080] Electric field distribution in Cabin F (electric field at 30 MHz): The electric field values range from -16 to 20 dBW / m² at a distance of 20 mm from the bottom metal plate. The electric field intensity is relatively large in the area near the generator. The values in most areas are between -5 and 10 dBW / m². The electric field values range from -39 to -9 dBW / m² at a distance of 320 mm from the bottom metal plate. The electric field intensity is relatively large in the area near the generator. The electric field values range from -27 to -17 dBW / m² at a distance of 620 mm from the bottom metal plate. The electric field intensity is relatively large in the area near the generator.

[0081] Analysis of simulation results: The electric field intensity is relatively large at the bottom area of Cabin F and in the area near the generator.

[0082] Electric field distribution in Region 1 (electric field at 30 MHz): The electric field values range from -20 to 15 dBW / m² at a distance of 10 mm from the skin of the nose. The electric field intensity is relatively large in the middle area, with values between 5 and 15 dBW / m². The electric field intensity is relatively small in the two side areas, with values concentrated between -5 and 5 dBW / m². The electric field values range from -28 to -10 dBW / m² at a distance of 210 mm from the skin of the nose. The electric field values range from -34 to -19 dBW / m² at a distance of 410 mm from the skin of the nose.

[0083] Analysis of simulation results: The electric field intensity is relatively large at the bottom area (near the fuselage skin) of Region 1, and gradually decreases in the middle and upper areas.

[0084] Electric field distribution in Region 2 (electric field at 30 MHz): The electric field values range from -30 to 37 dBW / m² at a distance of 20 mm from the skin of the tail pipe. The electric field intensity is relatively large in some local areas, with values between 20 and 37 dBW / m², and the electric field intensity values in most areas are between -30 and 0 dBW / m². The electric field values range from -32 to -12 dBW / m² at a distance of 320 mm from the skin of the tail pipe.

[0085] Analysis of simulation results: The overall electric field intensity in Region 2 is relatively small, but there are some local areas with relatively large electric field intensity, with the maximum reaching 37 dBW / m².

[0086] Electric field distribution in Region 3 (electric field at 30 MHz): The electric field values range from -48 to -8 dBW / m² at a distance of 30 mm from the skin of the upper end of the vertical stabilizer. The electric field values range from -36 to -34 dBW / m² at a distance of 330 mm from the skin of the upper end of the vertical stabilizer. The electric field values range from -36 to -34 dBW / m² at a distance of 530 mm from the skin of the upper end of the vertical stabilizer.

[0087] Analysis of simulation results: The overall electric field intensity in Region 3 is relatively small.

[0088] Electric field distribution in Region 4 (electric field at 30 MHz): The electric field values range from -24 to 8 dBW / m² at a distance of 10 mm from the skin of the tail pipe; from -44 to -12 dBW / m² at a distance of 210 mm from the skin of the tail pipe; and from -35 to -21 dBW / m² at a distance of 410 mm from the skin of the tail pipe.

[0089] Analysis of simulation results: The electric field intensity is relatively large in the upper region (near the aircraft skin), and relatively small in the middle and lower regions. The electric field intensity is relatively large in the front region (the forward direction of the aircraft), and relatively small in the rear region.

[0090] Electric field distribution in Region 5 (electric field at 30 MHz): The electric field values range from -28 to -8 dBW / m² on the plane parallel to the skin of the aircraft belly; from -28 to -21 dBW / m² at a distance of 300 mm from the skin of the aircraft belly.

[0091] Analysis of simulation results: The overall electric field intensity in Region 5 is relatively small.

[0092] Electric field distribution in Region 6 (electric field at 30 MHz): The electric field values range from -40 to -5 dBW / m² at a distance of 20 mm from the skin of the aircraft belly; the electric field intensity values in most regions are concentrated between 30 and -15 dBW / m²; from -30 to -14 dBW / m² at a distance of 320 mm from the skin of the aircraft belly.

[0093] Analysis of simulation results: The overall electric field intensity in Region 6 is relatively small.

[0094] (2) For the electric field simulation of the generator, according to the installation structure of the high-power microwave payload on the airborne platform, a complete equivalent model of the generator electric field source is designed and placed inside the airborne platform, and an excitation source is added at the gas switch position to simulate and analyze the overall electric field distribution at 40 MHz.

[0095] Electric field distribution in Compartment A (electric field at 40 MHz): The electric field values range from 45 to 70 dBW / m² at a distance of 20 mm from the bottom metal plate, and the values in most regions are between 55 and 65 dBW / m²; from 46 to 66 dBW / m² at a distance of 120 mm from the bottom metal plate; from 40 to 85 dBW / m² at a distance of 220 mm from the bottom metal plate; the electric field power density is relatively large in the region closer to the generator, with values between 65 and 85 dBW / m². The values in other regions are relatively small, mainly concentrated between 55 - 65 dBW / m².

[0096] Analysis of simulation results: The electric field is stronger when closer to the equivalent source, and the maximum value reaches 85 dBW / m²; the electric field power density in other regions is relatively small, and the values are mainly concentrated between 55 and 65 dBW / m².

[0097] Electric field distribution in Cabin B (electric field at 40 MHz): The electric field values at a distance of 20 mm from the bottom metal plate range from 6 to 36 dBW / m2, and the values in most areas are between 15 and 30 dBW / m2; the electric field values at a distance of 120 mm from the bottom metal plate range from 14 to 34 dBW / m2; the electric field values at a distance of 220 mm from the bottom metal plate range from 6 to 36 dBW / m2; the electric field power density is relatively large in the area closer to the generator, with values between 25 and 35 dBW / m2, and the values in other areas are relatively small, mainly concentrated between 15 and 25 dBW / m2.

[0098] Analysis of simulation results: The magnetic field is stronger when closer to the equivalent source, and the maximum value reaches 36 dBW / m2; the electric field power density in other areas is relatively small, and the values are mainly concentrated between 15 and 25 dBW / m2.

[0099] Electric field distribution in Cabin C (electric field at 40 MHz): The electric field values at a distance of 20 mm from the bottom metal plate range from -7.5 to 12.5 dBW / m2, and the values in most areas are between 0 and 10 - dBW / m2; the electric field values at a distance of 320 mm from the bottom metal plate range from -14 to 3.5 dBW / m2, and the values in most areas are between -10 and 0 dBW / m2; the electric field values at a distance of 720 mm from the bottom metal plate range from -20 to 5 dBW / m2, and the values in most areas are between -10 and 0 dBW / m2;

[0100] Analysis of simulation results: The electric field intensity is relatively large in the bottom area of Cabin C (at a distance of 20 m from the bottom metal plate), and the maximum value reaches 12 dBW / m2; the electric field intensity in the middle and upper areas is relatively small, and the values are mainly concentrated between -10 and 0 dBW / m2.

[0101] Electric field distribution in Cabin D (electric field at 40 MHz): The electric field values at a distance of 120 mm from the bottom metal plate range from -21 to 6 dBW / m2, and the values in most areas are between -15 and 0 dBW / m2; the electric field values at a distance of 320 mm from the bottom metal plate range from -20 to 0 dBW / m2; the values in most areas are between -14 and -4 dBW / m2; the electric field values at a distance of 720 mm from the bottom metal plate range from -20 to -2 dBW / m2; the values in most areas are between -16 and -6 dBW / m2.

[0102] Analysis of simulation results: The electric field intensity is relatively small in the bottom area of Cabin D, and the values are mainly concentrated between -16 and 0 dBW / m2. The electric field intensity is relatively large in some local areas at the edge, with a maximum value of 6 dBW / m2.

[0103] Electric field distribution in Cabin E (electric field at 40 MHz): The electric field values at a distance of 420 mm from the bottom metal plate range from -21 to 6 dBW / m2, and the values in most areas are between -15 and -5 dBW / m2; the electric field values at a distance of 720 mm from the bottom metal plate range from -24 to 30 dBW / m2; the values in most areas are between -14 and 0 dBW / m2; there are local areas (near the aircraft skin) where the electric field values are relatively large, with a maximum of 30 dBW / m2.

[0104] Analysis of simulation results: The electric field intensity in the bottom area of Cabin E is relatively small, and the values are mainly concentrated between -15 and 0 dBW / m2. The electric field intensity in the local area at the edge is relatively large, reaching a maximum of 30 dBW / m2.

[0105] Electric field distribution in Cabin F (electric field at 40 MHz): The electric field values at a distance of 20 mm from the bottom metal plate range from 36 - 42 dBW / m2, and the electric field intensity is relatively large in the area near the generator; the electric field values at a distance of 320 mm from the bottom metal plate range from 36 to 45 dBW / m2; the electric field intensity is relatively large in the area near the generator; the electric field values at a distance of 620 mm from the bottom metal plate range from 35 to 42 dBW / m2; the electric field intensity is relatively large in the area near the generator;

[0106] Analysis of simulation results: The electric field intensity in the bottom area of Cabin F is relatively large, and the values are concentrated between 35 and 45 dBW / m2; the electric field intensity in the front area (near the generator) is relatively large, and the electric field intensity in the rear area gradually decreases.

[0107] Electric field distribution in Region 1 (electric field at 40 MHz): The electric field values at a distance of 10 mm from the skin of the nose surface range from 39 to 54 dBW / m2, and the electric field intensity is relatively large at the joint of the metal skin and the fiberglass skin; the electric field values at a distance of 210 mm from the skin of the nose surface range from 38 to 48 dBW / m2; the electric field intensity is relatively large at the joint of the metal skin and the fiberglass skin; the electric field values at a distance of 410 mm from the skin of the nose surface range from 37 to 44 dBW / m2; the electric field intensity is relatively large at the joint of the metal skin and the fiberglass skin;

[0108] Analysis of simulation results: The electric field intensity in Region 1 is relatively large, and the values are concentrated between 37 and 54 dBW / m2: the electric field intensity in the rear area (near the generator) is relatively large, and the electric field intensity in the front area gradually decreases.

[0109] Electric field distribution in Region 2 (electric field at 40 MHz): The electric field values at a distance of 20 mm from the skin of the tail pipe surface range from 34 to 42 dBW / m2; the electric field values at a distance of 320 mm from the skin of the tail pipe surface range from 31 to 36 dBW / m2;

[0110] Analysis of simulation results: The electric field value at the bottom of Region 2 (near the skin of the tail pipe surface) is slightly larger, and the electric field value at the upper position is slightly smaller; the electric field intensity in the front region is larger, and the electric field intensity in the rear region gradually decreases.

[0111] Electric field distribution in Region 3 (electric field at 40 MHz): The electric field value ranges from 23 to 35 dBW / m2 at 30 mm from the skin of the upper end of the vertical fin; the electric field value ranges from 25 to 28 dBW / m2 at 330 mm from the skin of the upper end of the vertical fin; the electric field value ranges from 26 to 28 dBW / m2 at 530 mm from the skin of the upper end of the vertical fin;

[0112] Analysis of simulation results: The electric field intensity in Region 3 is relatively small, and the values are concentrated between 23 and 35 dBW / m2; the electric field intensity in the front region is larger, and the electric field intensity in the rear region gradually decreases.

[0113] Electric field distribution in Region 4 (electric field at 40 MHz): The electric field value ranges from 32 to 40 dBW / m2 at 10 mm from the skin of the tail pipe; the electric field value ranges from 31 to 35 dBW / m2 at 210 mm from the skin of the tail pipe; the electric field value ranges from 29 to 33 dBW / m2 at 410 mm from the skin of the tail pipe;

[0114] Analysis of simulation results: The electric field intensity in Region 4 is relatively small, and the values are concentrated between 29 and 40 dBW / m2; the electric field intensity in the rear region is larger, and the electric field intensity in the front region gradually decreases.

[0115] Electric field distribution in Region 5 (electric field at 40 MHz): The electric field value ranges from 27 - 29 dBW / m2 in the plane parallel to the skin of the belly; the electric field value ranges from 25 - 27 dBW / m2 at 300 mm from the skin of the belly;

[0116] Analysis of simulation results: The electric field intensity in Region 5 is relatively small, and the values are concentrated between 25 and 29 dBW / m2;

[0117] Electric field distribution in Region 6 (electric field at 40 MHz): The electric field value ranges from 26 to 33 dBW / m2 at 20 mm from the skin of the belly; the electric field value ranges from 25 to 30 dBW / m2 at 320 mm from the skin of the belly;

[0118] Analysis of simulation results: The electric field intensity in Region 6 is relatively small, and the values are concentrated between 25 and 33 dBW / m2.

[0119] (3) For the simulation of the magnetic field of the generator, place the equivalent model of the generator magnetic field source at the generator position and simulate and analyze the magnetic field distribution of the whole machine.

[0120] Magnetic field distribution in Compartment A: The magnetic field values range from 5 to 120 μT at a distance of 20 mm from the bottom metal plate; from 5 to 50 μT at a distance of 120 mm from the bottom metal plate; and from 0 to 6 mT at a distance of 220 mm from the bottom metal plate.

[0121] Analysis of simulation results: The magnetic field is stronger when closer to the equivalent source, with a maximum value reaching 6 mT; there is a magnetic induction effect on the metal plane, and the magnetic field strength value near the metal plane is greater than that at the middle position.

[0122] Magnetic field distribution in Compartment B: The magnetic field values range from 5 to 35 μT at a distance of 20 mm from the bottom metal plate; from 5 to 25 μT at a distance of 120 mm from the bottom metal plate; and from 0 to 3 mT at a distance of 220 mm from the bottom metal plate.

[0123] Analysis of simulation results: The magnetic field is stronger when closer to the source, with a maximum reaching 3 mT; there is a magnetic induction effect on the metal plane, and the magnetic field strength value near the metal plane is greater than that at the middle position.

[0124] Magnetic field distribution in Compartment C: The magnetic field values range from 2 to 35 μT at a distance of 20 mm from the bottom metal plate; from 1 to 12 μT at a distance of 320 mm from the bottom metal plate; and from 1 to 12 μT at a distance of 720 mm from the bottom metal plate.

[0125] Analysis of simulation results: There is a magnetic induction effect on the metal plane, and the magnetic field strength value near the metal plane is greater than that at the middle position; the change in the magnetic field strength in the middle region is relatively small, and the maximum value is basically 12 μT.

[0126] Magnetic field distribution in Compartment D: The magnetic field values range from 0 to 7 μT at a distance of 120 mm from the bottom metal plate; from 0 to 5 μT at a distance of 320 mm from the bottom metal plate; and from 1 to 8 μT at a distance of 620 mm from the bottom metal plate.

[0127] Analysis of simulation results: The change in the magnetic field strength on different height planes is relatively small, basically between 0 - 8 μT.

[0128] Magnetic field distribution in Compartment E: The magnetic field values range from 1 to 8 μT at a distance of 420 mm from the bottom metal plate; and from 1 to 8 μT at a distance of 720 mm from the bottom metal plate.

[0129] Analysis of simulation results: The change in the magnetic field strength on different height planes is relatively small, basically between 1 - 8 μT.

[0130] Magnetic field distribution in Compartment F: The magnetic field values range from 0 to 4 μT at a distance of 120 mm from the bottom metal plate; and from 0 to 2.4 μT at a distance of 420 mm from the bottom metal plate.

[0131] Analysis of simulation results: The magnetic field strength changes slightly on different height planes, basically between 0 and 4 μT.

[0132] Magnetic field distribution in Region 1: The magnetic field values range from 0 to 50 μT at a distance of 10 mm from the skin of the nose cone surface; the magnetic field values range from 1 to 1.8 μT at a distance of 210 mm from the skin of the nose cone surface; the magnetic field values range from Ⅰ to 1.5 μT at a distance of 410 mm from the skin of the nose cone surface.

[0133] Explanation of simulation results: When the distance is 10 mm from the skin of the nose cone surface, the magnetic field strength is relatively large, with a maximum of 50 μT; the magnetic field strength in other height regions is relatively small, with values between 1 and 1.8 μT; there is a magnetic induction effect on the metal plane, and the magnetic field strength value near the metal plane is greater than that in the middle position.

[0134] Magnetic field distribution in Region 2: The magnetic field values range from 0 to 220 μT (most regions are between 0 and 8 μT) at a distance of 20 mm from the skin of the tail pipe surface; the magnetic field values range from 0 to 1.2 μT at a distance of 320 mm from the skin of the nose cone surface.

[0135] Analysis of simulation results: When the distance is 20 mm from the skin of the tail pipe surface, the magnetic field strength is relatively large, with a maximum of 220 μT; the magnetic field strength in other height regions is relatively small, with values between 0 and 1.2 μT; the magnetic field strength value in the front section of Region 2 (near the nose cone direction) is relatively large.

[0136] Magnetic field distribution in Region 3: The magnetic field values range from 0.2 to 1.2 μT at a distance of 30 mm from the skin of the upper end of the vertical fin surface; the magnetic field values range from 0.22 to 0.35 μT at a distance of 330 mm from the skin of the upper end of the vertical fin surface; the magnetic field values range from 0.21 to 0.27 μT at a distance of 530 mm from the skin of the upper end of the vertical fin surface.

[0137] Explanation of simulation results: When the distance is 30 mm from the skin of the upper end of the vertical fin surface, the magnetic field strength is relatively large, with a maximum of 1.2 μT; the magnetic field strength in other height regions is relatively small, with values between 0.21 and 0.35 μT; there is a magnetic induction effect on the metal plane, and the magnetic field strength value near the metal plane is greater than that in the middle position.

[0138] Magnetic field distribution in Region 4: The magnetic field values range from 0 to 220 μT at a distance of 10 mm from the skin of the tail pipe surface; the magnetic field values range from 0.1 to 0.7 μT at a distance of 210 mm from the skin of the tail pipe surface; the magnetic field values range from 0.12 to 0.48 μT at a distance of 410 mm from the skin of the tail pipe surface.

[0139] Analysis of simulation results: When the distance is 10 mm from the skin of the tail pipe surface, the magnetic field strength is relatively large, with a maximum of 220 μT; the magnetic field strength in other height regions is relatively small, with values between 0.1 and 0.7 μT; there is a magnetic induction effect on the metal plane, and the magnetic field strength value near the metal plane is greater than that in the middle position.

[0140] Magnetic field distribution in Region 5: The magnetic field values in the plane parallel to the belly skin surface range from 0.2 to 1.2 μT; the magnetic field values at a distance of 300 mm from the belly skin surface range from 0.3 to 0.85 μT.

[0141] Analysis of simulation results: The change in the magnetic field strength in different height planes is relatively small, basically between 0.2 and 1.2 μT.

[0142] Magnetic field distribution in Region 6: The magnetic field values at a distance of 20 mm from the belly skin surface range from 0 to 5 μT; the magnetic field values at a distance of 320 mm from the belly skin surface range from 0 to 1.5 μT.

[0143] Analysis of simulation results: The magnetic field strength values in Region 6 are between 0 and 5 μT.

[0144] Step 7: Draw conclusions comprehensively for the overall electric field and overall magnetic field of the whole machine respectively.

[0145] (1) Summarize and analyze the simulation results of the electric field at 30 MHz

[0146] The electric field power density is relatively large in the upper regions of Compartments A and B near the generator, and relatively small in the middle and lower regions; there are local regions with relatively large electric field intensities in Region 2 and Compartment E, and the electric field intensities in other regions are basically less than 0 dBW / m2; the electric field intensities are relatively large in Region 1, Compartments C and F near the metal (aircraft flat skin and metal partition) plane, and the electric field intensities in the regions far from the metal surface are relatively small, basically less than 0 dBW / m2; there are local regions with relatively large electric field intensities in Region 4 and Compartment D, and the electric field intensities in other regions are basically less than -5 dBW / m2; the electric field intensities in Region 5, Region 6 and Region 3 are relatively small, and the values are basically less than -510 dBW / m2.

[0147] The order of the electric field strength distribution from large to small at the middle positions of each region is: Compartment B > Compartment A > Region 2 > Compartment E > Region 1, Compartments C and F > Region 4 and Compartment D > Region 5 and Region 6 > Region 3. Compared with the simulation results of the electric field distribution at 40 MHz, the electric field intensity at 30 MHz is significantly smaller. The electric field simulation results at 30 MHz are shown in Table 5.

[0148] Table 5 Electric field simulation results at 30 MHz

[0149]

[0150]

[0151]

[0152] (2) Summarize and analyze the simulation results of the electric field at 40 MHz

[0153] In the upper region near the generator in Cabin A and Cabin B, the electric field power density is relatively large, while in the middle and lower regions, it is relatively small; in the front regions (the forward direction of the aircraft) of Cabin F, Region 2, and Region 3, the electric field intensity is relatively large, and it gradually decreases in the rear regions; in the rear regions of Region 1 and Region 4, the electric field intensity is relatively large, and it gradually decreases in the front regions; in the regions near the gas switch (radiation source), namely Cabin A and the relevant regions, the electric field intensity is relatively large; due to the shielding effect of the metal plates, the electric field intensity in Cabin B, Cabin C, Cabin D, and Cabin E is the smallest; in Region 3 and Region 5, since they are far from the gas switch, the electric field intensity is relatively small.

[0154] The ranking of the electric field intensity distribution in the middle positions of each region from large to small is as follows: Cabin A > Region 1 > Cabin F > Region 2 and Region 4 > Region 3 and Region 5 > Cabin B > Cabin C > Cabin D > Cabin E.

[0155] The electric field simulation results at 40 MHz are shown in Table 6.

[0156] Table 6 Electric Field Simulation Results at 40 MHz

[0157]

[0158]

[0159] (3) Summarize and analyze the magnetic field simulation results

[0160] The simulation results of Cabin A to Cabin C and Region 1 to Region 4 show that the maximum value of the magnetic field intensity at positions where the distance from the metal plane is less than 30 mm is significantly greater than that at other positions. Based on this, it is inferred that the metal plane will generate a magnetic induction effect, resulting in a relatively large magnetic field intensity near the metal plane; the magnetic field intensity inside the airborne platform (Cabin A to Cabin F) is greater than that outside (Region 1 to Region 6);

[0161] The ranking of the magnetic field intensity distribution in the middle positions of each region (i.e., excluding the regions close to the metal plane) from large to small is as follows: Cabin A and Cabin B (5 - 50 μT) > Cabin C, Cabin D, and Cabin E (1 - 12 μT) > Cabin F (0 - 4 μT) > Region 1 to Region 6 (0 - 1.8 μT). The magnetic field simulation results are shown in Table 7.

[0162] Table 7 Magnetic Field Simulation Results

[0163]

[0164]

[0165] The embodiments of the present invention are only one form for illustrating the technical solutions, and their descriptions do not limit the protection scope of the present invention. Any equivalent replacement or improvement made by those skilled in the art without departing from the technical idea of the present invention shall fall within the protection scope of the present invention.

[0166] The technical solution of the present invention can be adjusted or optimized according to actual application requirements, and all such adjustments and optimizations are within the protection scope of the present invention. The protection scope of the present invention shall be subject to the claims, and the embodiments are only used to help understand the content of the present invention.

Claims

1. A simulation method for evaluating the radiation impact of an airborne high-power microwave generator on platform equipment, characterized in that It includes the following steps: S1. Design the equivalent model of the generator; S2. Preprocess the simulation model, divide the positions on the airborne platform where the generator can be installed into regions, and divide the interior into compartments; S3. According to the material setting function of the simulation software, perform equivalent processing on the materials of each part of the fuselage; S4. Generate triangular meshes through surface meshing, and determine the size and number of meshes according to the calculation frequency band; S5. Based on the simulation frequency and type, select electromagnetic simulation software and algorithms; S6. For the overall electric field of the machine, select the electric field frequency for simulation. For the overall magnetic field of the machine, simulate and analyze the distribution of the overall magnetic field; S7. For the overall electric field and the overall magnetic field of the machine respectively, analyze the ranking of the electric field / magnetic field intensity distribution from large to small at the middle positions of each region, and draw a conclusion.

2. The simulation method for evaluating the radiation impact of an airborne high-power microwave generator on platform equipment according to claim 1, characterized in that: The equivalent model of the generator in S1 includes the design of the equivalent model of the generator magnetic field source and the design of the equivalent model of the generator electric field; For the design of the equivalent model of the generator magnetic field source, design a spiral coil to simulate the magnetic field generated by the HPM source, and compare the simulation results and test results of the magnetic field distribution around the generator to ensure that the error is within 1 dB; For the design of the equivalent model of the generator electric field, combine the working principle of the high-power microwave payload to construct a generator model, retain the main metal structure and the main electrical connection parts of the generator. The model includes the primary energy source, MARX generator, horn antenna, spiral coil, metal floor and grounding wire. The gas switch is located inside the MARX generator, and the thyristor switch is located inside the primary energy source. At the same time, test and analyze the frequency range where the electric field frequency radiated by the generator is mainly concentrated.

3. The simulation method for evaluating the radiation impact of an airborne high-power microwave generator on platform equipment according to claim 1, wherein: In S2, use the CATIA software to model the airborne platform based on the scaled model of the unmanned helicopter, retain the aerodynamic shape of the helicopter, and simplify the internal structure. When simulating, take the axis direction of the helicopter as the Y-axis, the height direction of the helicopter as the Z-axis direction, and the width direction as the X-axis direction. The positions on the airborne platform for installing antennas are divided into six regions, defined as Region 1 to Region 6, and the interior is divided into six compartments, defined as Compartment A to Compartment F.

4. The simulation method for evaluating the radiation impact of an airborne high-power microwave generator on platform equipment according to claim 1, characterized in that: The definitions in S3 include: the material, equivalent conductivity, and thickness of the fuselage region; the materials of the optoelectronic pod, landing gear, and one-dimensional mechanical scanning radar; the materials of the tower and landing gear; the frequency.

5. The simulation method for evaluating the radiation impact of an airborne high-power microwave generator on platform equipment according to claim 1, wherein: Three-dimensional electromagnetic numerical simulation is used in S4.

6. The simulation method for evaluating the radiation impact of an airborne high-power microwave generator on platform equipment according to claim 1, characterized in that: Select the commercial electromagnetic simulation software FEKO in S5 and use the method of moments for simulation.

7. The simulation method for evaluating the radiation impact of an airborne high-power microwave generator on platform equipment according to claim 1, wherein: In S6, for the overall electric field of the machine, select the electric field frequency that has a greater impact on the platform for simulation. For the overall magnetic field of the machine, place the equivalent model of the generator magnetic field source at the generator position and simulate and analyze the distribution of the overall magnetic field.

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