Hostname: page-component-cd9895bd7-q99xh Total loading time: 0 Render date: 2024-12-21T11:02:07.606Z Has data issue: false hasContentIssue false

Control of circular cylinder flow using distributed passive jets

Published online by Cambridge University Press:  13 June 2018

Ben L. Clapperton
Affiliation:
Department of Aeronautics, Imperial College, London SW7 2AZ, UK
Peter W. Bearman
Affiliation:
Department of Aeronautics, Imperial College, London SW7 2AZ, UK

Abstract

A wind tunnel study has been carried out to investigate flow control around a hollow circular cylinder using passive jets driven by naturally occurring pressure differences. Flow enters the cylinder through spanwise holes along the stagnation line and exits through a spanwise distribution of holes at $\pm 65^{\circ }$. The diameter of the entry and exit holes were 1 % and 0.5 % of the cylinder diameter, respectively. Reynolds numbers were at the upper end of the subcritical regime and ranged from $3\times 10^{4}$ to $2.8\times 10^{5}$. Jet spacings of 10 % and 20 % of the cylinder diameter were investigated, and the ratio of the average jet exit velocity to the cross-flow velocity at the boundary layer edge was found to rise to approximately 0.35 and 0.4, respectively, above a Reynolds number of $1.5\times 10^{5}$. Findings based on using the surface oil flow technique revealed a repeating, organised cellular pattern downstream of adjacent jet exit holes consisting of a primary counter-rotating vortex pair structure, followed by a secondary weaker pair. Downstream of adjacent exit holes, and centred midway between them, there exists a separation bubble which delays final flow separation compared with the flow directly downstream of a jet. The variation in the angular position of boundary layer separation across the span had the effect of suppressing von Kármán vortex shedding. This resulted in a drag coefficient, at the upper end of the Reynolds-number range studied, 14.5 % lower than that found using trip wires to initiate boundary layer transition.

Type
JFM Papers
Copyright
© 2018 Cambridge University Press 

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

Achenbach, E. 1968 Distribution of local pressure and skin friction around a circular cylinder in cross-flow up to Re = 5 × 106 . J. Fluid Mech. 34 (4), 625639.CrossRefGoogle Scholar
Achenbach, E. 1971 Influence of surface roughness on the cross-flow around a circular cylinder. J. Fluid Mech. 46 (2), 321335.CrossRefGoogle Scholar
Allen, H. J. & Vincenti, W. G.1944 Wall interference in a two-dimensional-flow wind tunnel, with consideration of the effect of compressibility. NACA Tech. Rep. 782.Google Scholar
Andreopoulos, J. & Rodi, W. 1984 Experimental investigation of jets in a crossflow. J. Fluid Mech. 138, 93127.CrossRefGoogle Scholar
Bagheri, S., Schlatter, P., Schmid, P. J. & Henningson, D. S. 2009 Global stability of a jet in crossflow. J. Fluid Mech. 624, 3344.CrossRefGoogle Scholar
Bearman, P. W. 1969 On vortex shedding from a circular cylinder in the critical Reynolds number regime. J. Fluid Mech. 37 (3), 577585.CrossRefGoogle Scholar
Bearman, P. W. & Harvey, J. K. 1993 Control of circular cylinder flow by the use of dimples. AIAA J. 31 (10), 17531756.CrossRefGoogle Scholar
Bearman, P. W. & Owen, J. C. 1998 Reduction of bluff-body drag and suppression of vortex shedding by the introduction of wavy separation lines. J. Fluids Struct. 12, 123130.CrossRefGoogle Scholar
Cambonie, T., Gautier, N. & Aider, J. L. 2013 Experimental study of counter-rotating vortex pair trajectories induced by a round jet in cross-flow at low velocity ratios. Exp. Fluids 54 (1475), 113.CrossRefGoogle Scholar
Clapperton Surfleet, B. L.2017 Drag reduction of bluff bodies by passive control of boundary layer transition and separation. PhD thesis, Imperial College London.Google Scholar
Crouch, T. N., Burton, D., Brown, N. A. T., Thompson, M. C. & Sheridan, J. 2014 Flow topology in the wake of a cyclist and its effect on aerodynamic drag. J. Fluid Mech. 748, 535.CrossRefGoogle Scholar
Delery, J. M. 2001 Robert Legendre and Henri Werlé: toward the elucidation of three-dimensional separation. Annu. Rev. Fluid Mech. 33, 129154.CrossRefGoogle Scholar
Delery, J. M. 2011 Separation in three-dimensional flow: critical points, separation lines and vortices. In ONERA Information Resources. ONERA.Google Scholar
Fage, A. & Warsap, J. H.1930 The effects of turbulence and surface roughness on the drag of a circular cylinder. Tech. Rep. Ae 429. Aeronautical Research Committee, London.Google Scholar
Foss, J.1980 Interaction region phenomena for the jet in a cross-flow problem. Tech. Rep. Sonderforschungsbereich 80: Ausbreitungs- und Transportvorgänge in Strömungen, Universität Karlsruhe.Google Scholar
Fric, T. F. & Roshko, A. 1994 Vortical structure in the wake of a transverse jet. J. Fluid Mech. 279, 147.CrossRefGoogle Scholar
Igarashi, T. 1986 Effect of tripping wires on the flow around a circular cylinder normal to an airstream. Bull. JSME 29 (255), 29172924.CrossRefGoogle Scholar
James, D. F. & Truong, Q. S. 1972 Wind load on cylinder with spanwise protrusion. J. Engng Mech. Div. 98 (6), 15731589.CrossRefGoogle Scholar
JSME 1988 Visualized Flow, compiled by the Japan Society of Mechanical Engineers, English edn. (ed. Nakayama, Y., Woods, W. A. & Clark, D. G.). Pergamon.Google Scholar
Kelso, R. M. & Smits, A. J. 1995 Horseshoe vortex systems resulting from the interaction between a laminar boundary layer and a transverse jet. Phys. Fluids 7 (1), 153158.CrossRefGoogle Scholar
Mahesh, K. 2013 The interaction of jets with crossflow. Annu. Rev. Fluid Mech. 45 (1), 379407.CrossRefGoogle Scholar
Mizuno, S. 1970 Effects of three-dimensional roughness elements on the flow around a circular cylinder. J. Sci. Hiroshima Univ., Ser. A-II 34 (3), 215258.Google Scholar
Morkovin, M. V. 1964 Flow around circular cylinder: a kaleidoscope of challenging fluid phenomena. In Symposium on Fully Separated Flows, pp. 102118. American Society of Mechanical Engineers.Google Scholar
Perry, A. E. & Chong, M. S. 1986 A series-expansion study of the Navier–Stokes equations with applications to three-dimensional separation patterns. J. Fluid Mech. 173, 207223.CrossRefGoogle Scholar
Perry, A. E. & Chong, M. S. 1987 A description of eddying motions and flow patterns using critical-point concepts. Annu. Rev. Fluid Mech. 19 (1), 125155.CrossRefGoogle Scholar
Roshko, A. 1961 Experiments on the flow past a circular cylinder at very high Reynolds number. J. Fluid Mech. 10 (3), 345356.CrossRefGoogle Scholar
Stansby, P. K. 1974 The effects of end plates on the base pressure coefficient of a circular cylinder. Aeronaut. J. 78 (757), 3637.CrossRefGoogle Scholar
Tobak, M. & Peake, D. J. 1982 Topology of three-dimensional separated flows. Annu. Rev. Fluid Mech. 14, 6185.CrossRefGoogle Scholar
Zdravkovich, M. M. 1997 Flow Around Circular Cylinders: A Comprehensive Guide through Flow Phenomena, Experiments, Applications, Mathematical Models, and Computer Simulations. Vol. 1: Fundamentals. Oxford Science Publications.Google Scholar