caa a22 4500 606197540 CHVBK 20210128100930.0 cr unu---uuuuu 210128e20150701xx s 000 0 eng 10.1007/s00348-015-2020-9 doi (NATIONALLICENCE)springer-10.1007/s00348-015-2020-9 Effects of an upstream tetrahedron on the circular cylinder-flat plate juncture flow [Elektronische Daten] [R. Huang, C. Hsu, C. Chen] A technique of installing a tetrahedron at the upstream corner of the circular cylinder-flat plate juncture is developed to control the characteristic horseshoe vortices appearing in the natural juncture flow. The Reynolds numbers based on the cylinder diameter are within the range of 500-2900. The flow patterns and time-averaged velocity fields in the vertical symmetry plane and a horizontal plane near the flat plate of the natural and tetrahedron-controlled juncture flows are examined by using the laser-assisted particle flow visualization method and particle image velocimetry in a towing water tank. The flow approaching the circular cylinder-flat plate juncture can induce a characteristic horseshoe vortical flow consisting of a single vortex, dual vortex, or triple vortex. These horseshoe vortices appearing in the natural case may be changed to a characteristic mode of vortical flow, reverse flow, or forward flow when a tetrahedron is installed at the upstream corner of the juncture. The appearance of the vortical flow, reverse flow, or forward flow mode depends on the geometric parameters of normalized axial length, expansion angle, and tilt angle as well as the flow parameter of the Reynolds number. The vortical flow mode appears at small axial length of tetrahedron. The forward flow mode appears at the large axial length of tetrahedron. When the forward flow mode appears, the boundary-layer upstream of the circular cylinder does not separate. Therefore, the horseshoe vortices induced in the natural juncture flow disappear. The data bank consists of the design parameters of axial length, tilt angle, and expansion angle of the tetrahedron, which is provided as a figure. Springer-Verlag Berlin Heidelberg, 2015 Huang R. Department of Mechanical Engineering, National Taiwan University of Science and Technology, 10672, Taipei, Taiwan, ROC aut Hsu C. Graduate Institute of Applied Science and Technology, National Taiwan University of Science and Technology, 10672, Taipei, Taiwan, ROC aut Chen C. Department of Mechanical Engineering, National Taiwan University of Science and Technology, 10672, Taipei, Taiwan, ROC aut Experiments in Fluids Springer Berlin Heidelberg 56/7(2015-07-01), 1-15 0723-4864 56:7<1 2015 56 348 https://doi.org/10.1007/s00348-015-2020-9 text/html Onlinezugriff via DOI BK010053 XK010053 XK010000 Metadata rights reserved Springer special CC-BY-NC licence nationallicence 1 research-article jats NATIONALLICENCE NATIONALLICENCE NL-springer NATIONALLICENCE 856 40 https://doi.org/10.1007/s00348-015-2020-9 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Huang R. Department of Mechanical Engineering, National Taiwan University of Science and Technology, 10672, Taipei, Taiwan, ROC aut NATIONALLICENCE 700 1- Hsu C. Graduate Institute of Applied Science and Technology, National Taiwan University of Science and Technology, 10672, Taipei, Taiwan, ROC aut NATIONALLICENCE 700 1- Chen C. Department of Mechanical Engineering, National Taiwan University of Science and Technology, 10672, Taipei, Taiwan, ROC aut NATIONALLICENCE 773 0- Experiments in Fluids Springer Berlin Heidelberg 56/7(2015-07-01), 1-15 0723-4864 56:7<1 2015 56 348