caa a22 4500 445303034 CHVBK 20180317142603.0 cr unu---uuuuu 170323e20100401xx s 000 0 eng 10.1134/S0001433810020039 doi (NATIONALLICENCE)springer-10.1134/S0001433810020039 Churilov S. Institute of Solar-Terrestrial Physics, Siberian Branch, Russian Academy of Sciences, ul. Lermontova 126, a/ya 291, 664033, Irkutsk, Russia aut Three-dimensional instability of shear flows with inflection-free velocity profiles in stratified media with a high Prandtl number [Elektronische Daten] [S. Churilov] In stably stratified media with a Prandtl number Pr ≫ 1, vertical scales of the density (ℓ) and horizontal velocity variation (L) are quite different, ℓ/L = O(Pr−1/2) ≪ 1, and this influences the flow stability. In particular, shear flows without inflection points on the velocity profile are unstable even in an ideal incompressible fluid. The maximum instability growth rate for sufficiently small ℓ/L is of the same order as in homogeneous mixing layers, with mainly three-dimensional rather than two-dimensional oscillations increasing in a wide range of parameters. This paper focuses on the three-dimensional instability of such flows. It is shown that the spectrum of unstable oscillations is essentially anisotropic in the case of a relatively weak stratification when the bulk Richardson number J ≤ O[(ℓ/L)3/2]. The results of the asymptotic analysis are illustrated by calculations for a model flow in a two-layer medium (ℓ = 0) as well as for flows with values of ℓ/L corresponding to a temperature or salinity stratification of the water. Pleiades Publishing, Ltd., 2010 Izvestiya, Atmospheric and Oceanic Physics SP MAIK Nauka/Interperiodica 46/2(2010-04-01), 159-168 0001-4338 46:2<159 2010 46 11485 https://doi.org/10.1134/S0001433810020039 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1134/S0001433810020039 text/html Onlinezugriff via DOI NATIONALLICENCE 100 1- Churilov S. Institute of Solar-Terrestrial Physics, Siberian Branch, Russian Academy of Sciences, ul. Lermontova 126, a/ya 291, 664033, Irkutsk, Russia aut NATIONALLICENCE 773 0- Izvestiya, Atmospheric and Oceanic Physics SP MAIK Nauka/Interperiodica 46/2(2010-04-01), 159-168 0001-4338 46:2<159 2010 46 11485 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer