A.V.Voskoboinick, V.A.Voskoboinick, À.A.Voskoboinick, V.O.Gorban, I.M.Gorban Features of the vortex motion into junction flow between pile group of three-row bridge pair |
Applied hydromechanics, Vol. 11 (83) ¹ 2, (2009) |
| In this paper, the results of numeral and experimental researches dealing with the kinematics and dynamics of the horseshoe vortical systems, which are conditioned by interaction of stream with a three-row pile grillage established on a flat rigid surface are presented. The calculation algorithms and software were developed and the measuring complex, system of processing and the analysis of data were created. Numerical, visual and instrumental results shown that there are lateral flows between the piles of three-row grillage, whose intensity is largest between the first and the second piles and between the next to last and the last lateral piles. Interaction between the horseshoe vortical systems, which are formed around the piles and grillage construction, and the wake vortices generated behind these bluff bodies causes bifurcation in the vortical flow and appearance of the symmetric and asymmetric vortical structures that are convected downstream in the gaps between piles. Both the mean and fluctuation velocities around the streamlined pile constructions, the scales and position of forming and development of the coherent vortical structures and their kinematics and dynamic characteristics are estimated. It is set that the large-scale coherent horseshoe vortical system formed near-by the second lateral pile of three-row grillage has a greater size and rotation frequency then the quasistable horseshoe vortical system, which exists before the first central pile. Its equivalent diameter is approximately 0.5d, the rotation frequency is 1.5 Hz or St=0.41 and the peripheral velocity is equal approximately to 0.7U?, and the horseshoe vortex formed before the first central pile has diameter 0.3d, the rotation frequency 1 Hz or St=0.27 and its peripheral velocity is almost 0.56U?. |
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| TEXT LANGUAGE: Ukrainian |