scholarly journals Hybrid Deflection of Spoiler Influencing Radar Cross-Section of Tailless Fighter

Sensors ◽  
2021 ◽  
Vol 21 (24) ◽  
pp. 8459
Author(s):  
Zeyang Zhou ◽  
Jun Huang

With the continuous development of advanced fighters towards tailless and flying wing layouts, diverse control surfaces have become the mainstream design. To study the influence of spoiler control surface on the radar cross-section (RCS) of a tailless fighter, a calculation method is presented. The deflection angle of the spoiler is controlled by the fixed mode, linear mode, and smooth mode. The results show that the opening action of the spoiler will break the original stealth characteristics of the aircraft at the key azimuth angles of the head and tail. As the elevation angle increases, this adverse effect will spread to the side. The influence of the different dynamic deflection modes of the spoiler on the aircraft RCS is analyzed. Compared with the linear dynamic deflection mode, the smooth dynamic deflection mode is conducive to the reduction in the average RCS at the given head azimuth. The presented method is effective to study the influence of the spoiler deflection on the electromagnetic scattering characteristics of the tailless aircraft.

2018 ◽  
Vol 17 ◽  
pp. 02003
Author(s):  
Ji Liu ◽  
Peilin Huang ◽  
Yaodong Zhao ◽  
Jinzu Ji ◽  
Fengli Xue

This paper studies radar cross section of submarine sails on the water. Under the detection of the enemy’s airborne radar, considering the motion of the submarine, the sail model of radar pitch angle incidence range analysis is established. By using CATIA software, the 3D models of AKULA sail, SUBOFF sail and VICTOR sail are built. On the basis of the physical optics method and the equivalent currents method, the scattering characteristics of sails RCS(radar cross section) are simulated under X radar band. Through the microwave anechoic chamber test, this paper verifies the accuracy of the combination of the physical optics method and the equivalent electromagnetic flow method. The influence of the distance from the airborne radar to the sail on the pitch angle of the electromagnetic wave is discussed, with the elevation angle of the radar antenna varies. Then, we illustrate the characteristics of circumferential direction RCS of the sail under different pitch angles. Finally, the mean RCS of the sail at a given pitch angle is simulated. The results show that the AKULA sail is considerably superior to SUBOFF sail and VICTOR sail on stealth performance with the pitch angle less than 4° . But when the pitch angle exceeds 10°, the SUBOFF sail can be given priority.


Sensors ◽  
2020 ◽  
Vol 20 (7) ◽  
pp. 2097 ◽  
Author(s):  
Zeyang Zhou ◽  
Jun Huang

With the continuous improvement and development of armed helicopters, the research on their stealth characteristics has become more and more in depth. In order to obtain the complex effect of stealth characteristics caused by the high-speed rotation of rotor-like components, a dynamic scattering method (DSM) is presented. Rotation speed, azimuth, elevation angle, pitching angle, and rolling angle are studied and discussed in detail. The results show that the electromagnetic scattering characteristics of the main rotor and tail rotor are dynamic and periodic. This period characteristic is related to the rotation speed and attitude angle of the rotor. The radar cross-section (RCS) of the helicopter varies greatly at different observation angles and attitude angles, but the dynamic electromagnetic scattering effect caused by the main rotor and tail rotor cannot be ignored. The presented DSM is effective and efficient for studying the dynamic RCS of the rotor-type parts of a helicopter or the whole machine.


Author(s):  
Zeyang Zhou ◽  
Jun Huang

With the promotion and enhancement of stealth technology of helicopter rotor components, the research on the dynamic radar cross section (RCS) of helicopter rotor is becoming more and more important and imminent. In order to facilitate the calculation and analysis of the electromagnetic scattering characteristics during rotor rotation, a dynamic scattering calculation (DSC) method based on quasi-static principle (QSP) and grid coordinate transformation is presented. After analyzing the advantages and disadvantages of QSP, the dynamic principle is used to describe the rotation process of the rotor. Combined with the grid coordinate transformation method, the RCS of the rotor is accurately calculated by physical optics (PO) and physical theory of diffraction (PTD). Then the influence of azimuth, elevator angle and observation distance on rotor dynamic RCS is analyzed. The results show RCS of the tail rotor is indeed dynamic and periodic and its main influencing factors include azimuth and elevation angle. The proposed DSC method is efficient and effective for studying the dynamic RCS of tail rotor.


Author(s):  
Zeyang Zhou ◽  
Jun Huang ◽  
Chen Chen ◽  
Jiaren Zhang

In order to study the radar characteristics of blunt-hub rotor, a dynamic scattering method (DSM) based on physical optics and physical theory of diffraction is presented. Important influencing factors are analyzed and discussed, including rotor disk inclination, azimuth, elevation angle, and radar wave frequency. The radar cross section (RCS) of the blunt-hub rotor is used for comparison with conventional-hub rotor and sharp-hub rotor. The RCS performance of the blunt-hub rotor at different radar wave frequencies is close to that of the sharp-hub rotor. At larger positive elevation angles, the RCS∼azimuth performance of the blunt-hub rotor is not as good as the other two rotors, while the RCS performance of the blunt-hub rotor has an advantage under the larger negative elevation angle and the inclination of the rotor disk. The presented DSM is feasible and effective for learning the electromagnetic scattering characteristics of the blunt-hub rotor.


2012 ◽  
Vol 580 ◽  
pp. 170-174
Author(s):  
Zhang Xing Qi ◽  
Zhen Sen Wu ◽  
Zi Wen Yu ◽  
Hai Ying Li

The decomposition of the multivariate Non-Gaussian PDF in the sum of a Gaussian PDF instead of the Gram-Charlier series is investigated. Four parameters need to be found by minimizing the integrated square of the difference between Cox-Munk function and its approximation. The backscattering radar cross section (RCS) of the surface is calculated by the Kirchhoff approximation (KA) under different value of k using the formula of decomposition of the Non-Gaussian. The condition of KA satisfying electromagnetic scattering scale from Gaussian and Non-Gaussian surfaces is taken into account by computing the backscattering coefficients in HH and VV polarity.


2012 ◽  
Vol 233-236 ◽  
pp. 92-108 ◽  
Author(s):  
Yanlai Chen ◽  
Jan S. Hesthaven ◽  
Yvon Maday ◽  
Jerónimo Rodríguez ◽  
Xueyu Zhu

2021 ◽  
Vol 5 (2) ◽  
pp. 162-178
Author(s):  
A. A. Kazantsev ◽  
◽  
B. A. Samorodov ◽  
A. M. Terentev ◽  
◽  
...  

This paper focuses on application of spectral estimation methods for scattering center’s radar cross section estimation and reduction under given frequency-angular observation conditions. A methodological approach has been developed to reduce the local center’s radar cross section with given object overall dimensions. The developed methodological approach is based on parametric optimization of object geometry, firstly, to reduce the local scatterer radar cross section and, secondly, to maximize object payload. The problem overview is presented in the introduction. The first section is devoted to mathematical formulation of the problem. The following section includes the comparison analysis of the different types of geometrical shapes. As a result, the object with exponential profile is chosen as the best one due to the ability to manage rear vertex local scatterer amplitude by changing the curvature parameter. In the third section the optimal curvature parameter value of the exponential profile is justified for the given object overall dimensions and frequency-angular observation conditions. It is demonstrated that the main characteristic to analysis is two-dimension functional dependence of the local scatterer mean radar cross section from geometrical parameter and angle of observation. It is proved that this mentioned dependence may be received by the implementation such well-known spectral estimation method as CLEAN to the object sinogram. The recognition range is calculated for two different hypothetical radars to assert the efficiency. It is offered in the conclusion to complicate the developed approach with radio absorption materials implementation as the direction of the future investigations.


Energies ◽  
2020 ◽  
Vol 13 (21) ◽  
pp. 5802
Author(s):  
Zeyang Zhou ◽  
Jun Huang

With the continuous advancement of rotor dynamic electromagnetic scattering research, the radar cross-section (RCS) of turbofan engines has attracted more and more attention. In order to solve the electromagnetic scattering characteristics of a biaxial multirotor turbofan engine, a dynamic scattering method (DSM) based on dynamic simulation and grid transformation is presented, where the static RCS of the engine and its components is calculated by physical optics and physical theory of diffraction. The results show that the electromagnetic scattering of the engine is periodic when the engine is working stably, while the rotors such as fans and turbines are the main factors affecting the dynamic electromagnetic scattering and the ducts greatly increase the overall RCS level of the engine. The proposed DSM is effective and efficient for studying the dynamic electromagnetic scattering characteristic of the turbofan engine.


2011 ◽  
Vol 311-313 ◽  
pp. 1599-1602
Author(s):  
Xin Quan Wen ◽  
De Wan Shi ◽  
Jin Xu

Left-handed Materials (LHM) is a kind of structural materials of artificial cycle which permittivity ε and permeability μ are both negative. This article mainly studied the electromagnetic scattering characteristics of LHM by using the method of rigorous modal matching, and discussed the variation of corresponding elliptical eccentricity, its loss and negatively permittivity on the effect of radar cross section by numerical calculation .


Photonics ◽  
2021 ◽  
Vol 8 (6) ◽  
pp. 175
Author(s):  
Zeyang Zhou ◽  
Jun Huang ◽  
Chen Chen ◽  
Jiaren Zhang

To study the radar characteristics of the tiltrotor aircraft when considering rotor rotation and tilting actions, a dynamic calculation method (DCM) based on physical optics and physical theory of diffraction is presented. The results show that the radar cross section of a single rotor is dynamic and periodic when it rotates, while increasing the rotation speed can shorten this period. At a fixed tilt angle, the overall radar cross section of the cabin plus rotor still exhibits various dynamic characteristics at different azimuths when considering the rotation of the rotor. Increasing the tilt angle can better improve the electromagnetic scattering level of the rotor, but this easily makes the cabin and the outer end of the wing become a new source of strong scattering. In the heading direction, the dynamic radar cross section of the aircraft under a larger azimuth angle is lower when the cabin tilts from horizontal to vertical position. The presented DCM is feasible and effective to obtain the electromagnetic scattering characteristics of tiltrotor aircraft.


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