Study On The Scattering Of Rivet And Screw On Aircraft

With the development of stealth and anti-stealth technology, more requests are needed for the exact calculation of the Radar Cross Section (RCS) of the object. There are many rivets and screws used on the surface of aircraft. Usually, these rivets and screws are electrically small in size. Although a single rivet plays a slight role in scattering from the aircraft, but the contributions from a large amount of rivets can not be neglected. As yet, there is no literature about this specially. The basic conceptions, principles and methodology for RCS calculation are presented in this paper, with the emphasis on using the electric field integral equation with the moment method to discuss and analyze the scattering from arbitrary conductor. On the basis of analyzing objects in some typical shapes, different kinds of rivets and screws are calculated.Firstly, the impedance matrix is derived using the triangular current vector basis function with electric field integral equation (EFIE). Secondly, the Gauss integral corresponding triangular cell is used to reduce the time to fill the impedance matrix and the singular point in the integration is solved by coordinate transform etc. At the same time, the wavelet transform is used to solve the impedance matrix, which can speed up calculating the matrix equation. Thirdly, the conductors of typical shapes such as flat plate, sphere and circular disk are calculated based on the theory above, and the results are compared with those from the literature or derived by other methods. The good agreements demonstrate that the method proposed is efficient and practicable. Finally, the image method and other methods are used respectively to analyze the scattering of the rivets and screws in terms of their shapes. The more primary discussion of the RCS of several rivets is also presented.