Electromagnetic scattering by open circular waveguides
Abstract
Open circular waveguides are used to model jet engine inlets. The exact WienerHopf solution for scattering by a semiinfinite cylinder is studied in the resonance region, where the cylinder diameter is of the order of a wavelength. In particular, the WienerHopf factorization functions are calculated by numerical integration and compared to various approximations to define regions of validity. Scattering from the rim is studied as a function of frequency, incidence angle, and time. A rayoptic model for rim backscatter is discussed. The relative power absorption of the five lowest order waveguide modes is evaluated. Coupling of incident plane waves to waveguide modes, and radiation by these modes are shown to be related by reciprocity. The waveguide termination model for a jet engine assumes an incident waveguide mode strikes an axially symmetric cone on a flat plate. The various techniques for evaluating scattering by this structure are discussed, and the problem is solved for a few cases.
 Publication:

Ph.D. Thesis
 Pub Date:
 August 1980
 Bibcode:
 1980PhDT........29J
 Keywords:

 Electromagnetic Scattering;
 Engine Inlets;
 Waveguides;
 Functions (Mathematics);
 Numerical Integration;
 Communications and Radar