Российский фонд
фундаментальных
исследований

Физический факультет
МГУ им. М.В.Ломоносова
 

04.03 Отражение, дифракция и рефракция волн

 

Li Baolei, Li Tinghua, Wu Jun, Hui Ming, Yuan Gang, Zhu Yongsheng «An arbitrary-shaped acoustic cloak with merits beyond the internal and external cloaks» Акустический журнал, 63, № 1, с. pp. 45-53 (2017)

Based on transformation acoustics, an arbitrary-shaped acoustic cloak capable of functioning as an information exchange-enabling internal cloak and a movement-allowing external cloak is presented. The general expressions of material parameters for the acoustic cloaks with arbitrarily conformal or non-conformal boundaries are derived, and then the performances of developed cloaks are validated by full-wave simulations. Finally, the different characteristics of the linear and nonlinear transformations-based cloaks are compared and analyzed. The proposed cloak could lead to wider applications beyond that of normal cloaks, since it effectively compensates the insufficiencies of traditional internal and external cloaks. Besides, this work also provides a new method to design bifunctional device and suggests an alternative way to make a large object invisible.

Акустический журнал, 63, № 1, с. pp. 45-53 (2017) | Рубрика: 04.03

 

Alia A. «Application of Discrete Huygens Method for Diffraction of Transient Ultrasonic Field» Акустический журнал, 64, № 1, с. pp. 10-17 (2018)

Several time-domain methods have been widely used to predict impulse response in acoustics. Despite its great potential, Discrete Huygens Method (DHM) has not been as widely used in the domain of ultrasonic diffraction as in other fields. In fact, little can be found in literature about the application of the DHM to diffraction phenomenon that can be described in terms of direct and edge waves, a concept suggested by Young since 1802. In this paper, a simple axisymmetric DHM-model has been used to simulate the transient ultrasonic field radiation of a baffled transducer and its diffraction by a target located on axis. The results are validated by impulse response based calculations. They indicate the capability of DHM to simulate diffraction occurring at transducer and target edges and to predict the complicated transient field in pulse mode.

Акустический журнал, 64, № 1, с. pp. 10-17 (2018) | Рубрика: 04.03

 

Maltsev N.E. «Numerical Implementation of Huygens Principle for Scattering from a Smooth Ideal Surface» Акустический журнал, 65, № 5, с. pp. 467-470 (2019)

In 1678 Huygens formulated a principle postulating that each point on a wave front acts as a point source emitting a spherical wave which travels with a local velocity. The field at a given point some time later is then the sum of the fields of each of these point sources. In this article a numerical method is presented for 2D problems of sound propagation and scattering, conforming that physical assumptions.

Акустический журнал, 65, № 5, с. pp. 467-470 (2019) | Рубрика: 04.03

 

Поликарпова Н.В., Волошинов В.Б., Иванова П.А. «Отражение плоских акустических волн при наклонном падении на грань кристалла диоксида теллура» Акустический журнал, 65, № 6, с. 740-750 (2019)

Представлено описание феноменологии отражения объемных акустических волн в акустооптическом кристалле парателлурита в случае произвольного падения упругой волны на свободную границу раздела между кристаллом и вакуумом. Анализ проведен при произвольных углах падения акустических волн в плоскости XOY материала. Рассмотрены аномальные варианты отражения акустических волн, принципиально отличающиеся от известных, для которых исследовано преобразование энергии падающей упругой волны в энергию отраженных волн. При наклонном падении отмечены случаи строгого отражения волны навстречу падающей волне с эффективностью преобразования энергии, близкой к 100%.

Акустический журнал, 65, № 6, с. 740-750 (2019) | Рубрики: 04.03 06.03