caa a22 4500 469100494 CHVBK 20180323133043.0 cr unu---uuuuu 170328e19921101xx s 000 0 eng 10.1007/BF01051355 doi (NATIONALLICENCE)springer-10.1007/BF01051355 Kozlov V. Vladivostok aut Model of two-dimensional vortex motion with an entrainment mechanism [Elektronische Daten] [V. Kozlov] A model for describing the vertically averaged vortex motions of an incompressible viscous fluid with an arbitrary vertical structure of the bottom Ekman boundary layer is proposed. An approach similar to that adopted in [1] is used: the second moments of the deviations from the average velocities required in order to close the vorticity equation are calculated by means of the Ekman solution for gradient flows, which makes it possible to take the integral bottom boundary layer effect into account. As a result, these terms lead to a specific form of nonlinear friction with a coefficient that depends on the vorticity of the average flow. In the particular case of a constant vertical turbulent transfer coefficient the inaccuracies of the model described in [1] can be eliminated. The generalized vorticity equation obtained has solutions of the vorticity spot type with a uniform internal vorticity distribution, which can be effectively investigated by means of appropriate algorithms [2]. The mechanism of entrainment at the vorticity front is illustrated with reference to the example of the evolution of vorticity spots. An exact solution of the problem of the evolution of an elliptic vortex (generalized Kirchhoff vortex), which in the case of fairly strong anticyclonic vorticity degenerates first into a line segment (vortex sheet) and then into a point vortex, is constructed. Equations describing the dynamics of an elliptic vorticity spot in an external field with a linear dependence of the velocity on the horizontal coordinates and generalizing the classical Chaplygin-Kida model [3, 4] are constructed. Plenum Publishing Corporation, 1993 Fluid Dynamics Kluwer Academic Publishers-Plenum Publishers 27/6(1992-11-01), 793-798 0015-4628 27:6<793 1992 27 10697 https://doi.org/10.1007/BF01051355 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/BF01051355 text/html Onlinezugriff via DOI NATIONALLICENCE 100 1- Kozlov V. Vladivostok aut NATIONALLICENCE 773 0- Fluid Dynamics Kluwer Academic Publishers-Plenum Publishers 27/6(1992-11-01), 793-798 0015-4628 27:6<793 1992 27 10697 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer