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1

Solution of the plane wave diffraction problem by a strip with different boundary conditions on its faces

Emets V., Rogowski J.

Przegląd Elektrotechniczny

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2016

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R. 92, nr 7

72--74

EN

A two-dimensional problem of electromagnetic wave diffraction by a plane strip with different boundary conditions on its sides is in the focus of our study. The diffracted field is expressed by an integral in terms of the induced electric and magnetic current densities. Applying the representation theorem for the scattering field, the problem is reduced to the solutions of the integral equations. Numerical solutions and high-frequency asymptotics for the scattering field in the wave zone of the inclusion are presented.

PL

W artykule przedstawiono dwuwymiarowy problem dyfrakcji elektromagnetycznych fal na płaskim włączeniu z różnymi warunkami brzegowymi na jego powierzchniach. Pole dyfrakcji przedstawiono w postaci całki indukowanych elektrycznych i magnetycznych gęstości prądu. Stosując twierdzenie o reprezentacji dla rozproszonego pola problem sprowadza się do rozwiązań układu równań całkowych. Przedstawiono numeryczne oraz asymptotyczne rozwiązania dla zakresu wysokich częstotliwości dla rozproszonego pola w strefie falowej włączenia.

2

The reactance wave diffraction problem by a strip in a scale of Bessel potential spaces

Castro L. P., Natroshvili D.

Opuscula Mathematica

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2006

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Vol. 26, no. 2

289-303

EN

We consider a boundary-transmission problem for the Helmholtz equation, in a Bessel potential space setting, which arises within the context of wave diffraction theory. The boundary under consideration consists of a strip, and certain reactance conditions are assumed on it. Operator theoretical methods are used to deal with the problem and, as a consequence, several convolution type operators are constructed and associated to the problem. At the end, the well-posedness of the problem is shown for a range of regularity orders of the Bessel potential spaces, and for a set of possible reactance numbers (dependent on the wave number).

3

Longshore sediment transport at Golden Sands (Bulgaria)

Nikolov H., Trifonova E., Cherneva Z., Ostrowski R., Skaja M., Szmytkiewicz M.

Oceanologia

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2006

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No. 48 (3)

413-432

EN

The paper presents the results of studies on the qualitative and quantitative features of the littoral drift at Golden Sands (Bulgaria), carried out jointly by Polish and Bulgarian researchers. The mathematical modelling of physical coastal processes took wave transformation (wave diffraction and refraction; the effects of shoaling and wave breaking) and longshore sediment transport into account. The computations were carried out for the mean statistical annual wave climate, determined on the basis of IO BAS wave data, simulated using the WAM method from long-term Black Sea wind data. The results of sediment transport computations clearly show that its direction off the Golden Sands shore is from north to south.

4

Transverse diffraction of weakly nonlinear waves for a first order quasi-linear system involving source-like terms

Conforto F., Giambo S., Valenti G.

Journal of Technical Physics

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2004

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Vol. 45, no 1

55-69

EN

Making use of the ray theory and the method of asymptotic expansion of multiple scales, a study of the diffraction of weakly nonlinear waves in a direction transverse to the rays, through media described by dissipative or dispersive hyperbolic systems, is proposed. It is shown that the wave amplitude satisfies a generalized Zabolotskaya-Khokhlov equation in the dissipative case, or a generalized Kadomtsev-Petviashvili equation in the dispersive case. Moreover, plane, cylindrical and spherical waves are also investigated. The present approach is used to study wave diffraction in a heat-conducting fluid.

5

An exact solution of the problem of wave diffraction by asymmetrically transparent cylinder

Selezov I., Morozova L.

Vibrations in Physical Systems

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2000

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Vol. 19

247--248