scholarly journals Wind Turbine Radar Cross Section

2012 ◽  
Vol 2012 ◽  
pp. 1-14 ◽  
Author(s):  
David Jenn ◽  
Cuong Ton

The radar cross section (RCS) of a wind turbine is a figure of merit for assessing its effect on the performance of electronic systems. In this paper, the fundamental equations for estimating the wind turbine clutter signal in radar and communication systems are presented. Methods of RCS prediction are summarized, citing their advantages and disadvantages. Bistatic and monostatic RCS patterns for two wind turbine configurations, a horizontal axis three-blade design and a vertical axis helical design, are shown. The unique electromagnetic scattering features, the effect of materials, and methods of mitigating wind turbine clutter are also discussed.

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.


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.


2015 ◽  
Vol 764-765 ◽  
pp. 457-461 ◽  
Author(s):  
Shyh Kuang Ueng ◽  
Yao Hong Chan

This paper presents a Radar Cross Section (RCS) reduction method for wind turbines. In the proposed method, a reshaping procedure is utilized to generate waves or bumps on the surface of the wind-turbine tower. As the tower is illuminated by electromagnetic waves, the reflected rays are perturbed by the convex structures and the RCS of the wind turbine is decreased. Test results conclude that our modeling method reduces the average RCS values. The scatterings in the directions of the convex structures are significantly declined.


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.


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

2019 ◽  
pp. 68-76

Modelo Teórico de los Sistemas de Aerogeneración Eléctrica para las Turbinas Eólicas de Eje Vertical Theoretical Model of Electric Aerogeneration Systems for Vertical Axis Wind Turbines Anthony Pinedo, Guillermo Ramírez, Lincoln Chiguala, Juan Estrada, David Asmat, Renny Nazario, Daniel Delfín, Lourdes Noriega, Silvia Aguilar, Randy Rosas, Luisa Juárez DOI: https://doi.org/10.33017/RevECIPeru2009.0027/ RESUMEN Existen dos tipos de sistemas de aerogeneración eléctrica por turbinas eólicas, los llamados de eje horizontal (HAWT) y los de eje vertical (VAWT). Ambos proponen ventajas y desventajas, dependiendo de muchos factores. Pero en general, no fue hasta hace unos años que el segundo tipo había sido ignorado, debido a la poca potencia que producía en comparación con los HAWT. Pero con la adaptación de un sistema de levitación, y un nuevo sistema de inducción magnética, las VAWT, lograron incrementar notablemente la energía obtenida, llegando incluso a superar a los HAWT. A pesar que los modelos VAWT han sido harto estudiados en cuanto al esquema experimental y de diseño, no se formuló ninguna explicación sólida, partiendo de principios básicos, sobre el funcionamiento de los VAWT. En este trabajo, se propone un modelo teórico del funcionamiento de los mismos. Para ello, se realizan tres estudios: la interacción del viento con las aspas del aerogenerador, el sistema de levitación magnética y la producción de energía eléctrica por inducción magnética. Estos tres fenómenos, permiten definir y predecir el funcionamiento de tal sistema de aerogeneración. Además, permite «visualizar» la influencia de los diferentes parámetros sobre la eficiencia del sistema, y así pues, poder manejar, los parámetros que controlamos experimentalmente, para obtener una eficiencia óptima. Palabras clave: aerogeneración eléctrica, turbinas de aire, eje vertical, levitación magnética. ABSTRACT There are two types of systems of electric aerogeneration by using wind turbines, one is called horizontal axis wind turbine (HAWT) and the other one is called vertical axis wind turbine (VAWT). Both of them have advantages and disadvantages depending on many factors. Since the second one had produced lees power than the first one, they were ignored. However, the adaptation of a levitation system and a new system of magnetic induction made VAWT increase the power produced and exceed the HAWT. Although VAWT models were studied enough in the design and experimental scheme, there is no solid explanation, based on basic principles, on the operation of the VAWT. In this paper is proposed a theoretical model of VAWT operation. Therefore, three studies are done: the interaction between wind and blades of the turbine, the magnetic levitation system and the energy production by magnetic induction. Those studies make us able to know and predict the operation of those systems. Since, we shall know how many factors are affecting the efficiency of the system; we shall be able to control those parameters in order to get the best efficiency. Keywords: electric aerogeneration, vertical axis wind turbine, magnetic levitation.


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