Learning radar cross section of an intermeshing-rotor helicopter with blade pitch

PurposeThis study aims to study the radar cross-section (RCS) of an intermeshing rotor with blade pitch. Design/methodology/approachThe variation of rotor blade pitch is designed into three modes: fixed mode, linear mode and smooth mode. The dynamic process of two crossed rotors is simulated, where the instantaneous RCS is calculated by physical optics and physical theory of diffraction. FindingsIncreasing the pitch angle in the fixed mode can reduce the average RCS of rotor at the given head azimuth. The RCS curve of helicopter in linear mode and smooth mode will have a large peak in the side direction at the given moment. Although the blade pitch in smooth mode is generally larger than that in fixed mode, the smooth mode is conducive to reducing the peak and mean value of helicopter RCS at the given heading azimuth. Originality/valueThe calculation method for analyzing RCS of intermeshing rotor with variable blade pitch is established.