Non Linear Vortex Structures in Stratified Fluid Driven by Small-Scale Helical Force

Copyright © 2013 Anatoly Tur, Vladimir Yanovsky. This is an open access article distributed under the Creative Commons Attribu-tion License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. In this work, we consider the effect of a small-scale helical driving force on fluid with a stable temperature gradient with Reynolds number. At first glance, this system does not have any instability. However, we show that a large scale vortex instability appears in the fluid despite its stable stratification. In a non-linear mode this instability becomes saturated and gives a large number of stationary spiral vortex structures. Among these structures there is a stationary helical soliton and a kink of the new type. The theory is built on the rigorous asymptotical method of multi-scale de-velopment