A.V.Voskoboinick, V.A.Voskoboinick, À.A.Voskoboinick Junction flow of three-row pile grillage on a flat plate. Part 1. Horseshoe vortex generation |
Applied hydromechanics, Vol. 10 (82) ¹ 3, (2008) |
| The experimental research results on the study of generation and development of horseshoe and wake vortices, which are conditioned by interaction of stream with the three-row pile grillage, established on a flat rigid surface, are represented in this work. For carrying out of experiments the measuring complex, processing and the analysis data system is developed and created. The miniature thermistor velocity sensors and piezoresistive velocity head sensors are made. Visual measurements of the vortex flow structure are carried out in the junction region of a grillage and a flat plate by means of dye-stuffs and washed off contrast coatings. The convective velocity measurements of vortical structures near to bridge pair models was made by the thermistor sensors which are taking place in the correlation block that has allowed to determine not only velocity, but also a movement direction of the large-scale coherent vortices in the junction flows. Local and global sources of a bed scours before a complex pair are established. That is the horseshoe and wake vortices and also lateral currents between cylindrical piles. Intensity of the horseshoe vortices and wall shear stresses increases in front and rear regions of the three-row grillage. Group piles and lateral currents result in aperiodicity of the vertical tornado-similar wake vortices behind the streamlined constructions. The greatest shear stresses are observed before forward piles and between the first and second lateral piles of the three-row grillage. |
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| TEXT LANGUAGE: Ukrainian |