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N.S.Gorodetska, V.I.Nikishov, L.V.Tkachenko A numerical modeling of development of the Taylor-Goertler vortices in an unsteady Couette flow. 1. Influence of the initial energy of disturbances |
Applied hydromechanics, Vol. 14 (86) ¹ 2, (2012) |
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The results of numerical simulation of a regular perturbation vorticity
development in a boundary layer over a concave surface are presented. The
boundary layer is formed over the inner surface of the external cylinder
after its stop in a circular Couette flow between two rotating cylinders.
It is shown that initially a noticeable drop of the energy of regular vortical
perturbations introducing in flow is observed. The shape of mentioned
perturbations was close to that of Goertler longitudinal vortices. The drop
is connected with adaptation of vortices to the peculiarities of the flow.
The greater is the initial perturbations energy, the greater it is the drop
of energy of the initial disturbances. The vortical disturbances develop
and their energy increases with time and the nonlinear effects become
important. The influence of the nonlinear effects appears earlier for
the perturbations with greater energy. This influence causes a deviation of
the growth energy curves from the exponential law.
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KEY WORDS: numerical modeling, boundary layer, Taylor-Goertler vortices, energy increase |
| TEXT LANGUAGE: Russian |