Experiments on the flow field of a circular cylinder having a front vertical plate Ro, Ki-Deok;
The characteristics of the flow field of a circular cylinder having a small vertical plate at the upstream side are investigated by measuring the fluid force on the circular cylinder and by visualizing the flow field using particle image velocimetry. The experimental parameters are the width ratios (H/B = 0.2-0.6) of the vertical plates to the circular cylinder's diameter, and the gap ratios (G/B = 0-3) between the circular cylinder and the vertical plate. The drag reduction rate and Strouhal number of the circular cylinder increased and then decreased with G/B in the case of the same H/B. The drag reduction rate increased with H/B in the case of the same G/B. In the case of a circular cylinder having a small vertical plate, the stagnation regions are represented on the upstream and downstream sides of the circular cylinder, and the size of that region on the upstream side increased with H/B.
Fluid force reduction;Separated flow;Circular cylinder;Flow control;Vertical plate;
M. Gad-el-Hak, "Modern developments in flow control," Applied Mechchanics Reviews, vol. 49, no. 7, p. 365, 1996.
E. Achenbach, "Influence of surface roughness on the cross-flow around a circular cylinder," Journal of Fluid Mechanics, vol. 46, no. 2, pp. 321-335, 1971.
O. Guven, C. Farell, and V. C. Patel, "Surface roughness effects on the mean flow past circular cylinders," Journal of Fluid Mechanics, vol. 98, no. 4, pp. 673-701, 1980.
H. C. Lim and S. J. Lee, "An experimental study on drag reduction of grooved cylinders," Transactions of the Korean Society of Mechanical Engineers (B), vol. 25, no. 2, pp. 260-268, 2001 (in Korean).
K. Aoki, S. Lee, and M. Oki, "Drag and flow characteristics around the circular cylinder with grooves," Transactions of the Japan Society of Mechanical Engineers (B), vol. 64, no. 617, pp. 18-24, 1998.
K. D. Ro, "Drag reduction of cylinder with dimpled surface," Journal of the Korean Society of Marine Engineering, vol. 25, no. 1, pp. 155-161, 2001 (in Korean).
K. D. Ro and J. T. Park, "Drag reduction characteristics of cylinder having square dimpled surface," Journal of the Korean Society of Marine Engineering, vol. 26, no. 3, pp. 233-239, 2002 (in Korean).
E. A. Anderson and A. A. Szewczyk, "Effects of a splitter plate on the near wake of a circular cylinder in 2 and 3-dimensional Flow configurations," Experiments in Fluids, vol. 23, pp. 161-174, 1997.
J. Wu, C. Shu, and N. Zhao, "Investigation of flow characteristics around a stationary circular cylinder with an undulatory plate," European Journal of Mechanics B/Fluids, vol. 48, pp. 27-39, 2014.
S. Ozono, "Flow control of vortex shedding by a short splitter plate asymmetrically arranged downstream of a cylinder," Physics of Fluids, vol. 11, pp. 1200-1205, 1999.
S. H. Sun, J. Y. Hwang, and K. S. Yang, "Drag reduction on a circular cylinder using a detached splitter plate," Transactions of the Korean Society of Mechanical Engineers (B), vol. 25, no. 11, pp. 1632-1639, 2001.
T. Tsutsui and T. Igarashi, "Drag reduction of a circular cylinder in an air-stream," Journal Wind Engineering and Industrial Aerodynamics, vol. 90, pp. 527-541, 2002.
A. Prasad and C. H. K. Williamsion, "A method for the reduction of bluff body drag," Journal Wind Engineering and Industrial Aerodynamics, vol. 69-71, pp. 155-167, 1997.
K. D. Ro, D. B. Jo, Y J Yoon, and S J Park, "Experiments of flowfield of a square prism having a small vertical Plate," Journal of the Korean Society of Marine Engineering, vol. 38, no. 6, pp. 900-908, 2014 (in Korean).
K. D. Ro, "Characteristics of fluid force reduction of a square prism with a small triangular prism," Journal of the Korean Society of Marine Engineering, vol. 39, no. 3, pp. 1649-1656, 2015 (in Korean).