Hostname: page-component-8448b6f56d-c4f8m Total loading time: 0 Render date: 2024-04-19T15:41:43.635Z Has data issue: false hasContentIssue false

Wake transition in the flow around a circular cylinder with a splitter plate

Published online by Cambridge University Press:  22 August 2014

Douglas Serson
Affiliation:
NDF, Escola Politécnica, Universidade de São Paulo, Av. Prof. Mello Moraes, 2231, São Paulo, 05508-030, Brazil
Julio R. Meneghini*
Affiliation:
NDF, Escola Politécnica, Universidade de São Paulo, Av. Prof. Mello Moraes, 2231, São Paulo, 05508-030, Brazil
Bruno S. Carmo
Affiliation:
NDF, Escola Politécnica, Universidade de São Paulo, Av. Prof. Mello Moraes, 2231, São Paulo, 05508-030, Brazil
Ernani V. Volpe
Affiliation:
NDF, Escola Politécnica, Universidade de São Paulo, Av. Prof. Mello Moraes, 2231, São Paulo, 05508-030, Brazil
Rafael S. Gioria
Affiliation:
NDF, Escola Politécnica, Universidade de São Paulo, Av. Prof. Mello Moraes, 2231, São Paulo, 05508-030, Brazil
*
Email address for correspondence: jmeneg@usp.br

Abstract

A simple way to decrease the drag and oscillating lift forces in the flow around a circular cylinder consists of positioning a splitter plate in the wake, parallel to the flow. In this paper, the effect of the splitter plate on the wake dynamics, more specifically on the wake transition, is described in detail. First, two-dimensional and three-dimensional direct numerical simulations (DNS) using the spectral element method were used to observe the behaviour of the wake in the presence of the splitter plate. Then, a linear stability analysis based on the Floquet theory was performed in order to obtain information on how the splitter plate changes the instabilities that lead to wake transition. Simulations were carried out for several gaps between the splitter plate and the cylinder, with the Reynolds number varying in the range between 100 and 350, which corresponds to the wake transition in the flow around a circular cylinder. The results of the simulations showed a discontinuity in the Strouhal number curve that is consistent with the results available in the literature. The stability analysis showed how the splitter plate modifies the transition of the flow to a three-dimensional configuration. The splitter plate has a stabilizing effect on the flow for small gaps, delaying the appearance of three-dimensional structures to higher Reynolds numbers. Mode A and a quasi-periodic (QP) mode are observed for such small gaps. As the gap is increased the discontinuity in the Strouhal number curve also caused a clear change in the characteristics of the neutral stability curve, and the existence of an unstable period-doubling mode was observed. The onset characteristics of the unstable modes are analysed and discussed in depth.

Type
Papers
Copyright
© 2014 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

Apelt, C. J., West, G. S. & Szewczyk, A. A. 1973 The effects of wake splitter plates on the flow past a circular cylinder in the range $ 10^{4}<{R}<5\times 10^{4} $ . J. Fluid Mech. 61 (1), 187198.Google Scholar
Barkley, D. & Henderson, R. D. 1996 Three-dimensional Floquet stability analysis of the wake of a circular cylinder. J. Fluid Mech. 332, 215241.Google Scholar
Bearman, P. W. 1965 Investigation of the flow behind a two-dimensional model with a blunt trailing edge and fitted with splitter plates. J. Fluid Mech. 21 (2), 241255.Google Scholar
Blackburn, H. M., Marques, F. & Lopez, J. M. 2005 Symmetry breaking of two-dimensional time-periodic wakes. J. Fluid Mech. 522, 395411.Google Scholar
Carmo, B. S., Sherwin, S. J., Bearman, P. W. & Willden, H. J. 2008 Wake transition in the flow around two circular cylinders in staggered arrangements. J. Fluid Mech. 597, 129.Google Scholar
Chieregatti, B. G., Carmo, B. S. & Volpe, E. V. 2012 An investigation of the influence of splitter plates on the vortical wake behind a circular cylinder in cross-flow. In 10th World Congress on Computational Mechanics (ed. Pimenta, P. M.), pp. 114.Google Scholar
Gerrard, J. H. 1966 The mechanics of the formation region of vortices behind bluff bodies. J. Fluid Mech. 25 (2), 401413.Google Scholar
Igarashi, T. 1982 Investigation on the flow behind a circular cylinder with a wake splitter plate. Bull. JSME 25 (202), 528535.Google Scholar
Karniadakis, G. E. 1990 Spectral element-Fourier methods for incompressible turbulent flows. Comput. Meth. Appl. Mech. Engng 80 (1–3), 367380.Google Scholar
Karniadakis, G. E., Israeli, M. & Orszag, S. A. 1991 High-order splitting methods for the incompressible Navier–Stokes equations. J. Comput. Phys. 97 (2), 414443.Google Scholar
Karniadakis, G. E. & Sherwin, S. J. 2005 Spectral/hp Element Methods for Computational Fluid Dynamics, 2nd edn. Oxford University Press.Google Scholar
Kawai, H. 1990 Discrete vortex simulation for flow around a circular cylinder with a splitter plate. J. Wind Engng Ind. Aerodyn. 33 (1–2), 153160.Google Scholar
Korczak, K. Z. & Patera, A. T. 1986 An isoparametric spectral element method for solution of the Navier–Stokes equations in complex geometry. J. Comput. Phys. 62, 361382.Google Scholar
Kwon, K. & Choi, H. 1996 Control of laminar vortex shedding behind a circular cylinder using splitter plates. Phys. Fluids 8 (2), 479486.Google Scholar
Leweke, T. & Williamson, C. H. K. 1998 Three-dimensional instabilities in wake transition. Eur. J. Mech. (B/Fluids) 17 (4), 571586.Google Scholar
Marques, F., Lopez, J. M. & Blackburn, H. M. 2004 Bifurcations in systems with Z2 spatio-temporal and O(2) spatial symmetry. Physica D 189, 247276.CrossRefGoogle Scholar
Roshko, A.1954 On the drag and sheddind frequency of two-dimensional bluff bodies. NACA Tech. Note 3169.Google Scholar
Thompson, M. C., Leweke, T. & Williamson, C. H. K. 2001 The physical mechanism of transition in bluff body wakes. J. Fluids Struct. 15, 607616.Google Scholar
Williamson, C. H. K. 1988 The existence of two stages in the transition to three-dimensionality of a cylinder wake. Phys. Fluids 31 (11), 31653168.Google Scholar
Williamson, C. H. K. 1996 Three-dimensional wake transition. J. Fluid Mech. 328, 345407.Google Scholar