“…The results indicate that the VV RCS of flying wing aircraft is lower than the HH RCS at most angles, which is consistent with Ref. 31.Figure 6.Distribution of surface grid (3 GHz).Figure 7.Scattering characteristics of wing-01 at 3 GHz.Figure 8.Scattering characteristics of wing-01 at 6 GHz.Figure 9.Scattering characteristics of wing-01 at 10 GHz.…”
Section: Analysis Of Scattering Characteristics Of Rudder Seamsupporting
This work investigates the scattering characteristics of the rudder structure of aircraft considering electromagnetic discontinuities through multi level fast multipole algorithm (MLFMA) of the computational electromagnetics. Firstly, the scattering characteristics of the rudder seam and its influence on the omnidirectional radar cross section (RCS) are performed. Based on the traditional high-frequency analysis theory, the source and spatial contribution distribution of seam scattering are further studied. Numerical results demonstrate that the sidewall of the rudder seam is an important scattering source, and the radar absorbing material (RAM) coated on the sidewall of the seam has a good RCS reduction effect. In addition, this work presents the influence of the rudder deflection on the stealth performance, analyzes the effect of the rudder movement of the ordinary aileron and the split drag rudder on the scattering characteristics of the whole aircraft. The common aileron has little effect on the stealth performance of the aircraft, and it only causes scattering peak in the direction opposite to the control surface. However, the split drag rudder has great damage to the opposite direction stealth performance of the aircraft. When its deflection angle is 45°, the mean value of the opposite direction RCS increases by about two orders of magnitude compared with the deflection angle 0° state. The results indicate that the structure of aircraft rudder has a significant impact on the RCS characteristics of the whole aircraft.
“…The results indicate that the VV RCS of flying wing aircraft is lower than the HH RCS at most angles, which is consistent with Ref. 31.Figure 6.Distribution of surface grid (3 GHz).Figure 7.Scattering characteristics of wing-01 at 3 GHz.Figure 8.Scattering characteristics of wing-01 at 6 GHz.Figure 9.Scattering characteristics of wing-01 at 10 GHz.…”
Section: Analysis Of Scattering Characteristics Of Rudder Seamsupporting
This work investigates the scattering characteristics of the rudder structure of aircraft considering electromagnetic discontinuities through multi level fast multipole algorithm (MLFMA) of the computational electromagnetics. Firstly, the scattering characteristics of the rudder seam and its influence on the omnidirectional radar cross section (RCS) are performed. Based on the traditional high-frequency analysis theory, the source and spatial contribution distribution of seam scattering are further studied. Numerical results demonstrate that the sidewall of the rudder seam is an important scattering source, and the radar absorbing material (RAM) coated on the sidewall of the seam has a good RCS reduction effect. In addition, this work presents the influence of the rudder deflection on the stealth performance, analyzes the effect of the rudder movement of the ordinary aileron and the split drag rudder on the scattering characteristics of the whole aircraft. The common aileron has little effect on the stealth performance of the aircraft, and it only causes scattering peak in the direction opposite to the control surface. However, the split drag rudder has great damage to the opposite direction stealth performance of the aircraft. When its deflection angle is 45°, the mean value of the opposite direction RCS increases by about two orders of magnitude compared with the deflection angle 0° state. The results indicate that the structure of aircraft rudder has a significant impact on the RCS characteristics of the whole aircraft.
“…The concept of stealth aircraft design typically encompassed two fundamental components: the optimization of its aerodynamic shape and the utilization of advanced radar stealth materials. The former involved the meticulous shaping [1][2] [3] of the aircraft's external structure to minimize its radar cross-section, thereby rendering it less visible to enemy radar systems. Meanwhile, the latter involved the careful selection and integration of materials that exhibit low electromagnetic reflectivity.…”
The thin structure that possesses both excellent stealth and load-bearing capabilities has a high demand in the military. This article proposes a multifunctional composite laminates, along with its optimization strategy. The novel structure comprises several layers of Glass Fiber Reinforced Plastics and each layer has a fixed thickness. The matrix of each layer is made of polylactic acid dispersed with graphene oxide of varying volume fractions, which facilitates the transmission, absorption, and reflection of electromagnetic waves (EMW). The multi-objective optimization strategy of composite laminates is conducted by considering the ply orientation and volume fraction of graphene oxide as design variables, and the bending stiffness and EMW absorbing bandwidth of the overall structure as design objectives, meanwhile the JAYA, a metaheuristic algorithm is employed as the optimizer. The results demonstrate that the optimization algorithm can efficiently adjust the structure to an optimal state. Furthermore, compared with the original structure, the optimized structure has a 190% increase in load-bearing capacity and a 30.3% increase in EMW absorbing performance.
“…Due to the increasingly rigorous deployment of the modern air defense systems, the complete airspace defense can be formed under network radars such as PAVE PAWS and YLC-8B, which means UAVs rarely achieve penetration by relying on stealth characteristics alone. 1,2 Therefore, a significant area of research has been the combination of stealth characteristics and path planning methods in the complex network radar environment. [3][4][5] The radar cross-section (RCS) of a target is one of the key factors affecting radar detection capability.…”
Section: Introductionmentioning
confidence: 99%
“…The main contributions of this article are as follows: (1) The 3D sector search approach is presented to expand the track points by incorporating stealth UAV maneuverability, which aims to reduce the search range of the algorithm. (2) The heuristic function of the conventional A-Star algorithm is modified and the dynamic weighting factor χ i =μ i and threat estimation function SðnÞ are adopted to accurately estimate the path cost which can improve the quality and search efficiency of the optimal path. The stealth UAV attitude angle is added to the track points searched by the modified A-Star algorithm, and flight constraint conditions are given according to the maneuverability.…”
For stealth unmanned aerial vehicles (UAVs), path security and search efficiency of penetration paths are the two most important factors in performing missions. This article investigates an optimal penetration path planning method that simultaneously considers the principles of kinematics, the dynamic radar cross-section of stealth UAVs, and the network radar system. By introducing the radar threat estimation function and a 3D bidirectional sector multilayer variable step search strategy into the conventional A-Star algorithm, a modified A-Star algorithm was proposed which aims to satisfy waypoint accuracy and the algorithm searching efficiency. Next, using the proposed penetration path planning method, new waypoints were selected simultaneously which satisfy the attitude angle constraints and rank-K fusion criterion of the radar system. Furthermore, for comparative analysis of different algorithms, the conventional A-Star algorithm, bidirectional multilayer A-Star algorithm, and modified A-Star algorithm were utilized to settle the penetration path problem that UAVs experience under various threat scenarios. Finally, the simulation results indicate that the paths obtained by employing the modified algorithm have optimal path costs and higher safety in a 3D complex network radar environment, which show the effectiveness of the proposed path planning scheme.
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