Study on the influence of blade on electromagnetic scattering characteristics in the open-ended cavity

Abstract

The aero engine intake is the most important and strongest scattering source of the combat aircraft in the forward area. The incident electromagnetic wave will directly illuminate the fan/compressor blades which would change the forward radar cross section (RCS) distribution of the intake. The influence of the internal blade geometry parameter, including blade number, blade stages and the angle between two-stage blades on the RCS of the open-ended cavity was obtained by using the method of moment with the multi-layer fast multipole. The results show that the mean RCS of the cavity decreases with the increasing blade number in the smaller detection angle range. The mean RCS of the cavity increases with the increasing blade stage which changes the transmission path of the incident electromagnetic wave inside the cavity. And compared with the cavity with only one blade, the mean RCS with three-stage blades increases by more than 55%. With the angle between the two-stage blades increasing, the mean RCS of the cavity decreases first and then increases.