Parametric investigation of hydrodynamic stability of a boundary layer on a flat plate over two-layer compliant coatings
A.E. Darzhain1,2, A.V. Boiko3,4, V.M. Kulik5, A.P. Chupakhin1,2
1Lavrentyev Institute of Hydrodynamics SB RAS, Novosibirsk, Russia
2Novosibirsk State University, Novosibirsk, Russia
3Khristianovich Institute of Theoretical and Applied Mechanics SB RAS, Novosibirsk, Russia
4Tyumen State University, Tyumen, Russia
5Kutateladze Institute of Thermophysics SB RAS, Novosibirsk, Russia
Keywords: податливые покрытия, пограничный слой, гидродинамическая неустойчивость, критическое число Рейнольдса, compliant coatings, boundary layer, hydrodynamic instability, critical Reynolds number
Abstract
The results of a parametric study of hydrodynamic stability in linear formulation of the Blasius boundary layer stability over two-layer compliant coatings are presented. In the calculations, experimental data for real silicon rubbers of several types on the elasticity modulus and the loss factor as functions of deformation frequency are used. Eight pairs of the coatings have been considered. The effect of coating layer thickness and external flow velocity on flow stability, in particular, on the behavior of the critical Reynolds number, has been studied parametrically. The regions of the critical Reynolds number of nonmonotonic nature, characteristic of most of coatings under consideration, have been found. A qualitative explanation of this effect is given. An analysis of the behavior of the critical Reynolds number allows determination of the optimal ratio of coating thicknesses for interaction with the flow.
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