Hostname: page-component-cd9895bd7-mkpzs Total loading time: 0 Render date: 2024-12-20T07:42:28.563Z Has data issue: false hasContentIssue false
  • English
  • Français

Sting-free measurements on a magnetically supported right circular cylinder aligned with the free stream

Published online by Cambridge University Press:  17 January 2008

HIROSHI HIGUCHI ,
HIDEO SAWADA  and
HIROYUKI KATO
HIROSHI HIGUCHI
Affiliation:
Syracuse University, Syracuse, NY 13244, USA
HIDEO SAWADA
Affiliation:
Japan Aerospace Exploration Agency, Chofu, Tokyo 182-8522, Japan
HIROYUKI KATO
Affiliation:
Japan Aerospace Exploration Agency, Chofu, Tokyo 182-8522, Japan
Get access Rights & Permissions [Opens in a new window]

Abstract

The flow over cylinders of varying fineness ratio (length to diameter) aligned with the free stream was examined using a magnetic suspension and balance system in order to avoid model support interference. The drag coefficient variation of a right circular cylinder was obtained for a wide range of fineness ratios. Particle image velocimetry (PIV) was used to examine the flow field, particularly the behaviour of the leading-edge separation shear layer and its effect on the wake. Reynolds numbers based on the cylinder diameter ranged from 5×104 to 1.1×105, while the major portion of the experiment was conducted at ReD=1.0×105. For moderately large fineness ratio, the shear layer reattaches with subsequent growth of the boundary layer, whereas over shorter cylinders, the shear layer remains detached. Differences in the wake recirculation region and the immediate wake patterns are clarified in terms of both the mean velocity and turbulent flow fields, including longitudinal vortical structures in the cross-flow plane of the wake. The minimum drag corresponded to the fineness ratio for which the separated shear layer reattached at the trailing edge of the cylinder. The base pressure was obtained with a telemetry technique. Pressure fields and aerodynamic force fluctuations are also discussed.

Type
Papers
Information
Journal of Fluid Mechanics , Volume 596 , 25 January 2008 , pp. 49 - 72
Copyright
Copyright © Cambridge University Press 2008

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

Bearman, P. W. & Trueman, D. M. 1972 An investigation of the flow around rectangular cylinders. Aeron. Q. 23, 229–237.CrossRefGoogle Scholar
Berger, E. Scholz, D. & Schumm, M. 1990 Coherent vortex structures in the wake of a sphere and a circular disk at rest and under forced vibrations. J. Fluids Struc. 4, 231–257.CrossRefGoogle Scholar
Bigger, R., Higuchi, H. & Hall, J. W. 2006 Open-loop control of the disk wake in air and in water. AIAA Paper 2006-3187.CrossRefGoogle Scholar
Blevins, R. D. 1984 Applied Fluid Dynamics Handbook, Van Nostrand Reinhold.Google Scholar
Crowe, C. T., Elger, D. F. & Roberson, J. A. 2005 Engineering Fluid Mechanics, 8th Edn. pp. 447–455. John Wiley & Sons.Google Scholar
Eiffel, G. 1907 Recherches Expérimentales sur la Résistance de l'Air Exécutées à la Tour Eiffel., L. Maretheux, Impimeur.Google Scholar
Eiffel, G. 1913 The resistance of the air and aviation (translated by Hunsaker, J. C.). London: Constable Co., Boston: Houghton, Mifflin & Co.Google Scholar
Higuchi, H., van Langen, P., Sawada, H. & Tinney, C. E. 2006 Axial flow over a blunt circular cylinder with and without shear layer reattachment. J. Fluids Struc. 22, 949–959.CrossRefGoogle Scholar
Hoerner, S. F. 1958 Fluid Dynamic Drag, pp. 3–12. Published by author.Google Scholar
Judd, M., Vlajinac, M. & Covert, E. E. 1971 Sting-free drag measurements on ellipsoidal cylinders at transition Reynolds numbers. J. Fluid Mech. 48, 353–364.CrossRefGoogle Scholar
Kiya, M., Mochizuki, O., Tamura, H., Ishikawa, R. & Kushioka, K. 1991 Turbulence properties of an axisymmetric separation-and-reattaching flow. AIAA J. 29, 936–941.CrossRefGoogle Scholar
Kiya, M., Shimizu, M. & Mochizuki, O. 1997 Sinusoidal forcing of a turbulent separation bubble. J. Fluid Mech. 342, 119–139.CrossRefGoogle Scholar
Koenig, K. & Roshko, A. 1985 An experimental study of geometrical effects on the drag and flow field of two bluff bodies separated by a gap. J. Fluid Mech. 156, 167–204.CrossRefGoogle Scholar
Nakaguchi, H. 1978 Recent Japanese research on three-dimensional bluff-body flows relevant to road-vehicle aerodynamics. In Aerodynamic Drag Mechanisms of Bluff Bodies and Road Vehicles (ed. Sovran, G., et al. .), pp. 227–246. Plenum.CrossRefGoogle Scholar
Ohya, Y. 1994 Note on a discontinuous change in wake pattern for a rectangular cylinder. J. Fluids Struct. 8, 325–330.CrossRefGoogle Scholar
Ota, T. 1975 An axisymmetric separated and reattached flow on a longitudinal blunt circular cylinder. J. of Appl. Mech., June 1975, pp. 311–315.CrossRefGoogle Scholar
Pankhurst, R. C. & Holder, D. W. 1952 Wind-Tunnel Technique, Chapter 8. Sir Isaac Pitman & Sons.Google Scholar
Park, W.-C. & Higuchi, H. 1989 Computations of the flow past single and multiple bluff bodies by a vortex tracing method. University of Minnesota Supercomputer Institute Rep. UMSI 89/88.Google Scholar
Roberson, J. A., Lin, C. Y., Rutherford, G. S., & Stine, M. D. 1972 Turbulence effects on drag of sharp-edged bodies. J. Hydraul. Div. ASCE, 1187–1209.CrossRefGoogle Scholar
Roos, F. W. & Willmarth, W. W. 1971 Some experimental results on sphere and disk drag. AIAA J. 9, 285–291.CrossRefGoogle Scholar
Sawada, H., Higuchi, H., Kunimasu, T. & Suda, S. 2004 Drag coefficients of cylinders magnetically suspended in axial flow. J. Wind Engng 29, 55–62 (in Japanese).CrossRefGoogle Scholar
Sawada, H. & Kunimasu, T. 2001 Status of MSBS study at NAL. 6th Int. Symp. on Magnetic Suspension Technology, Oct. 7–11, Turin, Italy (ed. Genta, G., Schneider-Muntau, H., di Gloria, L. & Green, W.), pp. 163–168. Politecnico di Torino.Google Scholar
Sawada, H., Kunimasu, T., Suda, S., Misunou, T. & Higuchi, H. 2005 Relation between base pressure and fineness ratio of axial cylinder. 37th Fluid Dynamics Conference, Sept. 15–16, Chiba, Japan (in Japanese).Google Scholar
Schlichting, H. 1968 Boundary layer theory. McGraw-Hill.Google Scholar
Sigurdson, L. W. 1995 Structure and control of a turbulent reattaching flow. J. Fluid Mech. 298, 139–165.CrossRefGoogle Scholar
Watanabe, S. & Kato, H. 2003 Stereo PIV applications to large-scale low-speed wind tunnels. AIAA Paper 2003-0919.CrossRefGoogle Scholar