Browsing by Author "Ufimtsev, Pyotr Ya."

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Citation Count: 1
Comments on "Wave diffraction by a soft/hard strip: Modified theory of physical optics solution"
(Elsevier Gmbh, Urban & Fischer verlag, 2018) Apaydin, Gokhan; Sevgi, Levent; Ufimtsev, Pyotr Ya.
Modified theory of physical optics (MTPO) solution for a soft/hard strip is analyzed. It is shown that this solution is incorrect because the MTPO Green function does not satisfy boundary conditions. Defects of MTPO in calculations of fringe waves are also noticed. (C) 2018 Elsevier GmbH. All rights reserved.
Citation Count: 11
Diffraction at a Rectangular Plate: First-Order PTD Approximation
(Ieee-inst Electrical Electronics Engineers inc, 2016) Apaydin, Gokhan; Hacivelioglu, Feray; Sevgi, Levent; Gordon, William B.; Ufimtsev, Pyotr Ya.
Physical theory of diffraction (PTD) is developed for the field scattered at a perfectly conducting rectangular plate. Grazing incidence and grazing scattering are analyzed. High-frequency asymptotic estimations are derived. Bistatic and monostatic scenarios are considered. Comparison is presented with known experimental and numeric results obtained by the method of moments (MoM).
Citation Count: 2
Diffraction at trilateral cylinders with combinations of soft and hard faces: first-order PTD approximation
(Taylor & Francis inc, 2018) Hacivelioglu, Feray; Apaydin, Gokhan; Sevgi, Levent; Ufimtsev, Pyotr Ya.
The paper investigates diffraction at trilateral cylinders with combinations of soft (electric) and hard (magnetic) faces. Scattered field in far zone is calculated according to the physical theory of diffraction. The first-order high-frequency approximation is constructed as a sum of single-diffracted edge waves. Plotted numerical data clearly demonstrate the difference for objects with different faces. Substantial suppression of backscattering is observed for cylinders with soft-hard illuminated faces. Fringe wave contributions to the scattered field are shown. Physical theory of diffraction results are compared with those of the physical optics and confirmed by the method of moments.
Citation Count: 1
Diffraction of acoustic waves at two-dimensional hard trilateral cylinders with rounded edges: First-order physical theory of diffraction approximation
(Acoustical Soc Amer Amer inst Physics, 2018) Apaydin, Gokhan; Sevgi, Levent; Ufimtsev, Pyotr Ya.
The paper explores diffraction of acoustic waves at a two-dimensional hard trilateral cylinder with rounded edges. It represents the extension of the physical theory of diffraction (PTD) for finite objects with rounded edges. A first-order PTD approximation is developed. Integral equations are formulated for acoustic fringe waves and solved by method of moments (MoM). Good agreement is observed with the exact solution found by MoM when the object size exceeds a few wavelengths. (C) 2018 Acoustical Society of America.
Citation Count: 5
Fringe integral equations for the 2-D wedges with soft and hard boundaries
(Amer Geophysical Union, 2016) Apaydin, Gokhan; Sevgi, Levent; Ufimtsev, Pyotr Ya.
Novel, fringe wave integral equations that account for the diffraction from nonpenetrable wedges with both soft and hard boundaries are derived. Method of moments simulation of fringe waves generated by a plane wave that excites the wedge is performed using this fringe wave integral equation. The results are compared with the exact physical theory of diffraction fringe waves.