Exhaust Plume Effects on Missile Scattering Currents

Theoretical predictions of the plane-wave induced uniform-mode scattering current on a typical missile with exhaust plume are presented. An approximate'math­ ematical model is derived based on body-of-revolution theory, the moment method, an impedance-sheet repre­ sentation and recently achieved plume conductivity pro­ files. Particular attention is paid to the modifica­ tion of missile current due to the presence of the plume. This effort supplements recently reported work based on thin-wire modeling of both missile and plume. The significant width of the plume, about eight times the missile diameter, warrants the more sophisticated modeling employed here. Frequencies considered cor­ respond to missile electrical lengths approximately between 0.1 and 1.0 wavelengths. The excitation direc­ tions considered are between broadside and 15° off missile axis.