V.A.Voskoboinick, A.V.Voskoboinick, A.A.Voskoboinick, V.M.Stepanovitch, I.A.Khizha Vortex movement inside complex geometry dimple |
Applied hydromechanics, Vol. 17 (89) ¹ 4, (2015) |
| The visual research results of the generation and evolution of the vortex flow inside the cavities on a flat surface in the form of single V- and Λ-shaped dimples that streamlined flow at different angles are presented. Visualization was performed using water-soluble coatings and contrast dyes, which were introduced in the flow wall layer. In conditions of a laminar flow inside the cavities of complex geometric shapes vortex structures are not generated. For a transitional and turbulent flow inside the V-shaped dimple were formed horseshoe vortex structures that with the increase in velocity is reduced in size and is pressed to the separation wall of the dimple. The periodically ejections of small-scale vortex sheet were observed in the midsection of such dimple. The spiral vortex structures were generated inside the Λ-shaped dimple that periodically ejecting and moving in the wake of the dimple formed a pair of counter-rotating vortices. The formation and emission of vortex structures were difference when the angle V- and Λ-shaped hole in the plane of the plate was changed. For the laminar flow of the Strouhal number of potential fluid ejection was ranged from 0.05 to 0.14. In conditions of the transition and turbulent flow the Strouhal number of the vortex structure and vortex sheet ejections was increased from 0.15 to 0.5. |
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KEY WORDS: cavity, visualization, coherent vortex structure, vortex sheet, ejection |
| TEXT LANGUAGE: Ukrainian |