CN-121997484-A - Design and preparation method of electromagnetic equivalent physical model of high-temperature radome

CN121997484ACN 121997484 ACN121997484 ACN 121997484ACN-121997484-A

Abstract

The invention discloses a design and preparation method of an electromagnetic equivalent physical model of a high-temperature radome, which realizes the accurate simulation of aiming errors of the high-temperature radome under the working condition of high-speed flight at normal temperature by increasing the thickness of a radome wall caused by dielectric temperature drift of a dielectric sheet simulation material attached to the surface of the normal-temperature radome, and comprises the steps of obtaining an instantaneous temperature field of the radome under the action of flight aerodynamic heat load through simulation; selecting a typical time point according to an instantaneous temperature field, carrying out sub-partition segmentation on the outer surface of the antenna housing, calculating the thickness of a sub-partition dielectric sheet based on a high-frequency method, preparing the sub-partition dielectric sheet, and attaching the sub-partition dielectric sheet. The invention provides a reliable physical model for semi-physical simulation and aiming error compensation of the high-speed aircraft guidance system, and can effectively solve the problem of the consistency of the ground and the sky faced by the current ground semi-physical simulation test and antenna housing aiming error compensation of the high-speed aircraft guidance system.

Inventors

JI JIANMIN
DONG YUEHUA
YIN KAI
CHEN BO
WANG KAIBIN
REN JIANHUA

Assignees

北京遥感设备研究所

Dates

Publication Date: 20260508
Application Date: 20251226

Claims (10)

1. The design method of the electromagnetic equivalent physical model of the high-temperature radome is characterized by comprising the following steps of: the method comprises the steps of obtaining an instantaneous temperature field of the radome under the action of flight aerodynamic thermal load through simulation; Selecting a typical point in time according to the instantaneous temperature field; carrying out sub-partition segmentation on the outer surface of the radome; And calculating the thickness of the medium sheet of the sub-partition based on a high-frequency method and the temperature data of the typical time point.
2. The method of claim 1, wherein the aerodynamic heat load is a cold wall heat flow, recovery enthalpy and pressure over time, or a hot wall heat flow over time, or a temperature over time.
3. The method of claim 1, wherein the representative point in time is located first within an operating period of the guidance system and second wherein the representative point in time has a highest temperature response.
4. The method of claim 1, wherein the sub-dividing the outer surface of the radome is performed by first dividing the outer surface of the radome into N sub-areas S n along the axial direction, requiring the height of the dielectric sheet to be not more than one vacuum working wavelength λ0 in order to ensure the fitting degree and equivalent precision of the dielectric sheet and the radome body, and then further dividing each sub-area S n into M sub-areas S n,m along the circumferential direction.
5. The method of claim 4, wherein the number of sub-partitions S n,m of each sub-region S n is not less than four.
6. The method according to claim 4, wherein the calculating the thickness of the dielectric sheet of the sub-partition based on the high frequency method is specifically: Based on a local flat-plate approximation theory, electromagnetic waves emitted by a radar antenna are irradiated on each sub-subarea S n,m to be approximately plane wave incident medium flat plates, wherein an incident point I n,m of the inner surface of the sub-subarea S n,m is an intersection point of an inner surface normal n and the inner surface passing through the center of the outer surface of the sub-subarea S n,m , and an incident angle theta n,m is an included angle between a connecting line OI n,m of the incident point I n,m and the center point of an antenna port surface and the inner normal n; through the thickness of the dielectric sheet, the state of plane waves after passing through the normal-temperature electromagnetic equivalent physical model is the same as the state of plane waves after passing through the high-temperature radome in high-speed flight, namely: Wherein, the For the incident electric field to be incident, And (3) with The voltage complex transmission coefficients of the high-temperature radome and the electromagnetic equivalent physical model thereof in the sub-partition S n,m are respectively; According to the temperature gradient distribution and the dielectric temperature drift characteristics of the cover material, the cover wall of the high-temperature antenna cover partition S n,m is equivalent to an N s -layer non-uniform medium plate, while the sub-partition S n,m of the electromagnetic equivalent physical model is regarded as a double-layer medium plate, and the multi-layer medium plate and the double-layer medium plate are respectively calculated by an equivalent transmission line method to obtain the antenna cover And (3) with At the thickness of the medium sheet Setting an objective function for the design variable Wherein K A 、K P is a weight coefficient, the marks V, H represent a vertical polarization component and a parallel polarization component of an incident plane wave respectively, The power transfer coefficient deviations for the perpendicular polarization component and the parallel polarization component respectively, Inserted phase shift deviations for perpendicular and parallel polarization components, respectively The calculation expression of the variables is as follows: Wherein the symbol S represents V or H, And (3) with The voltage complex transmission coefficients of the high-temperature radome and the electromagnetic equivalent physical model thereof in the sub-partition S n,m are respectively, And (3) with The insertion phases of the high-temperature radome and the electromagnetic equivalent physical model thereof in the sub-partition S n,m are respectively, Phase shift for the corresponding insert; Obtaining the optimal thickness of the dielectric sheet through iterative optimization So that the objective function And obtaining the minimum value, namely, the state of the plane wave after passing through the electromagnetic equivalent physical model at normal temperature is closest to the state of the plane wave after passing through the actual high-temperature radome.
7. A method for preparing an electromagnetic equivalent physical model of a high-temperature radome, based on the design method of any one of claims 1 to 6, characterized by comprising the following steps: preparing a sub-partition dielectric sheet, wherein the dielectric sheet is made of a low-loss flexible dielectric material with a relative dielectric constant close to that of a radome body material at normal temperature, and the flexible dielectric sheet forming process comprises hot pressing, injection molding and extrusion; For the case that the outer surface of the radome is an inextensible surface, in order to ensure the conformability and the fitting degree of the dielectric sheet and the radome, the height h n,m of the subarea is required to be not too large when the subarea is divided, so that the outline curve of the subarea is approximate to a straight line, and the outer surface of the subarea can be approximate to an extensible curved surface; the planar unfolding structure size of the dielectric sheet can be calculated by the following formula: Wherein y n,m1 、y n,m2 、h n,m is a known amount.
8. The method of claim 7, wherein the sub-zone dielectric sheets are attached to the sub-zones corresponding to the radome, specifically, the dielectric sheets of the sub-zone S n,m of each sub-zone S n are assembled into a complete dielectric ring by bonding, and then the dielectric ring is sleeved on the outer surface of the radome.
9. A computer readable storage medium, on which a computer program is stored, characterized in that the program, when being executed by a processor, implements the steps of the method according to any one of claims 1-8.
10. A computer device comprising a memory, a processor and a computer program stored on the memory and executable on the processor, characterized in that the processor implements the steps of the method according to any of claims 1-8 when the program is executed by the processor.

Description

Design and preparation method of electromagnetic equivalent physical model of high-temperature radome Technical Field The invention relates to the technical field of radomes, in particular to a design and preparation method of a high-temperature radome electromagnetic equivalent physical model considering a dielectric temperature drift effect. Background To improve burst and remote precision hit capability, aircraft are moving toward higher flight speeds, longer flight distances, and higher probe guidance precision. The precision probe guidance devices are used as the "brain" and "eyes" of the aircraft, and are usually located at the forefront of the aircraft, and radio frequency probe guidance technology is mostly adopted to highlight all-weather detection capability, so that great demands are made on the high performance of the matched protective cover-radome. The radome is used for protecting the detection guidance equipment, is positioned at the forefront end of the aircraft, forms the aerodynamic appearance of the aircraft, and is an important coupling link of the detection guidance equipment. Radomes are typically composed primarily of wave-transparent radomes, attachment rings, and the like, which are subjected to the relatively harshest aerodynamic thermal loads during high speed flight in the atmosphere. Currently, semi-physical simulation of aircraft guidance systems and radome aiming error compensation are usually carried out at normal temperature, and the radome used does not consider the influence of actual flight aerodynamic thermal load. However, when the guidance system actually works, the aircraft is in a high-speed flight state, and is influenced by the aerodynamic thermal load of the flight, the dielectric temperature drift of the cover material can induce the electromagnetic property of the cover material to drift, so that the electrical property deviates from the original design value. Therefore, the radome model in the actual flight state should be used in the semi-physical simulation and aiming error compensation test of the guidance system. However, due to the limitations of the test technology, it is very difficult to apply a corresponding thermal load to the radome during the semi-physical simulation and aiming error compensation test. Along with the continuous improvement of the flying speed of an aircraft and the continuous improvement of the requirements on the guidance precision, the development of a physical model capable of equivalent electromagnetic characteristics of the radome under the actual high-speed flying working condition is needed, and a vivid and reliable radome physical model is provided for ground simulation test and aiming error compensation of a guidance system, so that the consistency of the simulation test and the error compensation is effectively ensured. Wave-transparent ceramics such as quartz ceramics and silicon nitride ceramics are currently widely used as radome materials for high-speed aircraft due to excellent temperature resistance and rigidity. However, the dielectric constant and conductivity increase with increasing temperature, and the temperature increases more sharply when the threshold value is exceeded. As the flying speed continues to rise, the ground simulation test and aiming error compensation of the high-speed aircraft guidance system increasingly need to consider the influence of dielectric temperature drift of the material in flight. Disclosure of Invention Based on the above, the invention aims to provide a design and preparation method of an electromagnetic equivalent physical model of a high-temperature radome taking the dielectric temperature drift effect into consideration, and the accurate simulation of the aiming error of the high-temperature radome under the high-speed flight working condition at normal temperature is realized by attaching a dielectric sheet with specific thickness to the surface of the normal-temperature radome to simulate the increase of the thickness of the wall of the radome caused by the dielectric temperature drift. In order to achieve the above purpose, the invention adopts the following technical scheme: In a first aspect, an embodiment of the present application provides a method for designing an electromagnetic equivalent physical model of a high-temperature radome, which is characterized by comprising the following steps: the method comprises the steps of obtaining an instantaneous temperature field of the radome under the action of flight aerodynamic thermal load through simulation; Selecting a typical point in time according to the instantaneous temperature field; carrying out sub-partition segmentation on the outer surface of the radome; And calculating the thickness of the medium sheet of the sub-partition based on a high-frequency method and the temperature data of the typical time point. In an alternative, the aerodynamic heat load is a cold wall heat flow over time, a recovery enthalpy and a