A.A.Gourjii, V.V.Meleshko, E.I.Nikiforovich, R.J.Adrian Modelling of dynamics of hairpin vortex in turbulent boundary layer |
Applied hydromechanics, Vol. 8 (80) ¹ 2, (2006) |
| The interaction of system of horseshoe (hairpin) vortices in a boundary layer with profile of unperturbated laminar and averaged turbulent layers above a firm surface is considered. A vortex model based on thin vortex tube within the framework of model of an ideal incompressible fluid is formed. The comparative analysis of kinematic and dynamic characteristics of results of numerical modeling with results of real experiment and known theoretical solutions is carried out. The main regularity of interaction of hairpin system of vortex structures in shift flow above a firm surface are investigated. The comparison of numerical modeling results with experimental data gives an insignificant deviation in a removal velocity of horseshoe vortical structures from a firm surface. Removal velocity of vortices from firm surfaces is characterized by a corner Q. The numerical modeling data and experimental data coincide, Q»6o. Note that the removal velocity of vortices remains constant during enough long time interval and, probably, does not depends on a vortex geometry. Researches shows that dynamics of horseshoe vorices above a firm plane is defined basically by the type of a shift flow profile and boundary layer thickness, instead of absolute value of an external velocity flow. |
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| TEXT LANGUAGE: Russian |