Evaluation of base shield plates effectiveness in reducing the drag of a rough circular cylinder in a cross flow

다국어 초록 (Multilingual Abstract)

An experimental investigation has been conducted to determine the effectiveness of base shield plates in reducing the drag of a rough circular cylinder in a cross flow at Reynolds numbers in the range 3×104⁴≤ Re ≤10.5×104⁴. Three model configurations were investigated and compared: a plane cylinder (PC), a cylinder with a splitter plate (MC1) and a cylinder fitted with base shield plates (MC2). Each configuration was studied in the sub and supercritical flow regimes. The chord of the plates, L, ranged from 0.22 to 1.50D and the cavity width, G, between the plates was in the range from 0 to 0.93D. It is recognized that base shield plates can be employed more effectively than splitter plates to reduce the aerodynamic drag of circular cylinders in both the sub- and supercritical flow regimes. For subcritical

flow regime, one can get 53% and 24% drag reductions for the MC2 and MC1 models with L/D = 1.0, respectively, compared with the PC model. For supercritical flow regime however, the corresponding drag reductions are 38% and 7%.

참고문헌 (Reference)

1 Robertson, A.P, "Wind-induced fatigue loading of tubular steel lighting columns" Wind Struct 4 (4): 163-176, 2001

2 Ozono,S, "Vortex suppression of the cylinder wake by deflectors" 91-99, 2003

3 Nakamura,Y, "Vortex shedding from bluff bodies and a universal strouhal number" 159-171, 1996

4 Achenbach,E, "Total and local heat transfer from a smooth circular cylinder in cross – flow at high Reynolds number" 1387-1396, 1975

5 Dalton, C, "The suppression of lift on a circular cylinder due to vortex shedding at moderate Reynolds numbers" 617-628, 2001

6 Apelt, C.J, "The effects of wake splitter plates on the flow past a circular cylinder in the range 104 < R < 5´104" 187-198, 1973

7 West, G.S, "The effects of tunnel blockage and aspect ratio on the mean flow past a circular cylinder with Reynolds numbers between 104 and 105" 361-377, 1982

8 Nakamura, Y, "The effects of surface roughness on the flow past circular cylinders at high Reynolds numbers" 363-378, 1982

9 Stansby,P.K, "The effects of end plates on the base pressure coefficient of a circular cylinder" 36-37, 1974

10 Kwon, S.H, "The effects of drag reduction by ribbons attached to cylindrical pipes" 1945-1958, 2002

11 Akilli, H, "Suppression of vortex shedding of circular cylinder in shallow water by a splitter plate" 211-219, 2005

12 Szechenyi,E, "Supercritical Reynolds number simulation for two-dimensional flow over circular cylinders" 529-542, 1975

13 Alam, M., "Reduction of fluid forces acting on a single circular cylinder and two circular cylinders by using tripping rods" 347-366, 2003

14 Hwang, J, "Reduction of flow – induced forces on a circular cylinder using a detached splitter plate" 15 (15): 2433-2436, 2003

15 Leea, J, "Reducing the drag on a circular cylinder by upstream installation of a small control rod" 233-250, 2004

16 Bouak, F, "Passive control of the aerodynamic forces acting on a circular cylinder" 112-121, 1998

17 Unal M.F, "On vortex formation from a cylinder. Part 2. Control by splitter-plate interference" 513-529, 1987

18 Isaev, A, "Numerical study of the bleeding effect on the aerodynamics coefficients of circular cylinder" 90 (90): 1217-, 2002

19 Uematsu, Y, "Mechanism of ovalling vibrations of cylindrical shells in cross flow" Wind Struct 4 (4): 85-100, 2001

20 Bearman,P.W, "Investigation of the flow behind a two-dimensional model with a blunt trailing edge and fitted with splitter plates" 241-255, 1965

21 Achenbach,E, "Influence of surface roughness on the cross – flow around a circular cylinder" 321-335, 1971

22 Ozono S, "Flow control of vortex shedding by a short splitter plate asymmetrically arranged downstream of a cylinder" 11 (11): 1070-6631, 1999

23 Zdravkovich,M, "Flow Around Circular Cylinders, Vol. 1: Fundamentals" Oxford University Press 1997

24 Peil, U, "Fatigue of tubular steel lighting columns under wind load" Wind Struct 5 (5): 463-478, 2002

25 Nash, J.F, "Experiments on two dimensional base flow at sub-sonic and transonic speeds" Aeronautical Research Council 1963

26 Ribeiro,J.D, "Effects of surface roughness on the two-dimensional flow past circular cylinders I: mean forces and pressures" 37 (37): 299-309, 1991

27 Anderson, E, "Effects of a splitter plate on the near wake of a circular cylinder in 2 and 3 – dimensional flow configurations" 161-174, 1997

28 Rathakrishnan,E, "Effects of a splitter plate on bluff body drag" 37 (37): 1125-, 1999

29 Kruiswyk, R, "Effects of a base cavity on subsonic near-wake flow" 28 (28): 1885-1893, 1990

30 Igarashi,T, "Effect of tripping - wires on the flow around a circular cylinder normal to an airstream" 29 (29): 2917-2924, 1986

31 Choi, B, "Drag reduction with a sliding wall in a flow over a circular cylinder" 38 (38): 715-717, 2000

32 Hwang, J, "Drag reduction on a circular cylinder using dual detached splitter plates" 551-564, 2007

33 Zhang, P, "Drag reduction of a disk with an upstream rod" Wind Struct 9 (9): 245-254, 2006

34 Tsutsui, T, "Drag reduction of a circular cylinder in an air-stream" 527-541, 2002

35 El-Khairy,N, "Drag reduction of a circular cylinder at subcritical flow regime using base shield plates" 6 (6): 347-356, 2003

36 Igarashi, T., "Drag reduction of a circular cylinder (1st Report, Flow control using a small rod)”" 60 (60): 1554-1560, 1994

37 Sangil Kim, "Characteristics of fluctuating lift forces of a circular cylinder during generation of vortex excitati" 한국풍공학회 9 (9): 109-124, 2006

38 Yajima, Y, "A note on the drag reduction of a circular cylinder due to double rows of holes" 237-243, 1996

39 Lesage, F, "A method of reducing drag and fluctuating side force on bluff bodies" 229-245, 1987

40 Tanner,M, "A method for reducing the base drag of wings with blunt trailing edge" Aeronautical Quarterly 15-22, 1972