Тhe consequences of the modulation instabilities

• Дата: 2018
• Автор: Kuklin, V.M.
• Формат: Стаття
• Мова: English
• Опубліковано: Національний науковий центр «Харківський фізико-технічний інститут» НАН України 2018
• Назва видання: Вопросы атомной науки и техники
• Теми: Нелинейные процессы
• Онлайн доступ: http://dspace.nbuv.gov.ua/handle/123456789/147442
• Назва журналу: Digital Library of Periodicals of National Academy of Sciences of Ukraine
• Цитувати: Тhe consequences of the modulation instabilities / V.M. Kuklin // Вопросы атомной науки и техники. — 2018. — № 4. — С. 225-229. — Бібліогр.: 30 назв. — англ.

The paper demonstrates the consequences of modulation instability of intense periodic structures in wave and non-wave media. In the case of a large dissipation level, near and above the threshold, the instability leads to the excitation of spectra whose width narrows, forming narrow spectral lines and self-similar structure of the big spatial clearness. At an insignificant level of dissipation, far from the threshold of modulation instability, the wave motion (initiated by the source) forms anomalous amplitude waves and envelopes exceeding the average amplitude by at three times. The shape of the envelope or wave packet is similar to the shape of Peregrine breather, and the dynamics over time is also similar. The formation of self-similar spatial structures in the developed convection of a thin liquid or gas layer due to the development of modulation instability is presented. In this case, toroidal convection vortices generate poloidal vortices of large scale − the effect of a hydrodynamic dynamo. Experimental results of the investigation of emerging self-similar structures on the graphite surface are presented. The features of the development of parametric instabilities are discussed.