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The effect of porosity on the drag of cylinders

Published online by Cambridge University Press:  24 August 2020

K. Steiros*
Affiliation:
Department of Aeronautics, Imperial College London, LondonSW7 2AZ, UK Department of Mechanical and Aerospace Engineering, Princeton University, Princeton, NJ08544, USA
K. Kokmanian
Affiliation:
Department of Mechanical and Aerospace Engineering, Princeton University, Princeton, NJ08544, USA
N. Bempedelis
Affiliation:
Department of Mechanical Engineering, University College London, LondonWC1E 7JE, UK
M. Hultmark
Affiliation:
Department of Mechanical and Aerospace Engineering, Princeton University, Princeton, NJ08544, USA
*
Email address for correspondence: k.steiros13@imperial.ac.uk

Abstract

It is well known that perforation of a flat plate reduces its drag when exposed to a flow. However, studies have shown an opposite effect in the case of cylinders. Such a counterintuitive result can have significant consequences on the momentum modelling often used for wind turbine performance predictions, where increased porosity is intrinsically linked to lower drag. Here, a study of the drag of various types of porous cylinders, bars and plates under steady laminar inflow is presented. It is shown that, for most cases, the drag decreases with increased porosity. Only special types of perforations can increase the drag on both cylinders and bars, either by enhancing the effect of the rear half of the models or by organizing the wake structures. These rare occurrences are not relevant to wind turbine modelling, which indicates that current momentum models exhibit the qualitatively correct behaviour.

JFM classification

Type
JFM Rapids
Copyright
© The Author(s), 2020. Published by Cambridge University Press

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References

REFERENCES

Alridge, T. R., Piper, B. S. & Hunt, J. C. R. 1978 The drag coefficient of finite-aspect-ratio perforated circular cylinders. J. Wind Engng Ind. Aerodyn. 3 (4), 251257.CrossRefGoogle Scholar
Apelt, C. J. & West, G. S. 1975 The effects of wake splitter plates on bluff-body flow in the range $10^4 < R< 5 \times 10^4$. J. Fluid Mech. 71 (1), 145160.CrossRefGoogle Scholar
Ayati, A. A., Steiros, K., Miller, M. A., Duvvuri, S. & Hultmark, M. 2019 A double-multiple streamtube model for vertical axis wind turbines of arbitrary rotor loading. Wind Energy Sci. 4 (4), 653662.CrossRefGoogle Scholar
Bahaj, A. S., Molland, A. F., Chaplin, J. R. & Batten, W. M. J. 2007 Power and thrust measurements of marine current turbines under various hydrodynamic flow conditions in a cavitation tunnel and a towing tank. J. Renew. Energy 32, 407426.CrossRefGoogle Scholar
Breuer, M. 1998 Large eddy simulation of the subcritical flow past a circular cylinder: numerical and modeling aspects. Intl J. Numer. Meth. Fluids 28 (9), 12811302.3.0.CO;2-#>CrossRefGoogle Scholar
Castro, I. P. 1971 Wake characteristics of two-dimensional perforated plates normal to an air-stream. J. Fluid Mech. 46 (3), 599609.CrossRefGoogle Scholar
Ferreira, C. S., Madsen, H. A., Barone, M., Roscher, B., Deglaire, P. & Arduin, I. 2014 Comparison of aerodynamic models for vertical axis wind turbines. J. Phys.: Conf. Ser. 524, 110.Google Scholar
Graham, J. M. R. 1976 Turbulent flow past a porous plate. J. Fluid Mech. 73 (3), 565591.CrossRefGoogle Scholar
Hansen, M. O. L. 2008 Aerodynamics of Wind Turbines. Earthscan.Google Scholar
Huang, Z., Kawall, J. G. & Keffer, J. F. 1996 Development of structure within the turbulent wake of a porous body. Part 2. Evolution of the three-dimensional features. J. Fluid Mech. 329, 117136.CrossRefGoogle Scholar
Hunt, J. C. R., Wray, A. A. & Moin, P. 1988 Eddies, streams, and convergence zones in turbulent flows. Tech. Rep. CTR-S88, 193–208. Center for Turbulence Research.Google Scholar
Igarashi, T. 1978 Flow characteristics around a circular cylinder with a slit: 1st report, flow control and flow patterns. Bull. JSME 21 (154), 656664.CrossRefGoogle Scholar
Jones, G., Horvarth, T. J., Stainback, P. C., Beasley, W. D. & McGhee, R. J. 1987 Literature review and experimental results for a cylinder with perforations and protrusions at high Reynolds numbers. In 19th AIAA, Fluid Dynamics, Plasma Dynamics, and Lasers Conference, pp. 1–24. AIAA.CrossRefGoogle Scholar
Koo, J.-K & James, D. F. 1973 Fluid flow around and through a screen. J. Fluid Mech. 60 (3), 513538.CrossRefGoogle Scholar
Maskell, E. C. 1965 A theory of the blockage effects on bluff bodies and stalled wings in a closed wind tunnel. Aero. Res. Counc. R. & M. no. 3400.Google Scholar
Newman, B. G. 1986 Multiple actuator-disk theory for wind turbines. J. Wind Engng Ind. Aerodyn. 24, 215225.CrossRefGoogle Scholar
Ning, A. 2016 Actuator cylinder theory for multiple vertical axis wind turbines. Wind Energy Sci. 1 (2), 327340.CrossRefGoogle Scholar
Ong, L. & Wallace, J. 1996 The velocity field of the turbulent very near wake of a circular cylinder. Exp. Fluids 20 (6), 441453.CrossRefGoogle Scholar
Osgood, D. B. 2000 Oscillating flow about perforated cylinders. Master's thesis, Naval Postgraduate School, Monterey, CA.Google Scholar
Paraschivoiu, I. 1988 Double-multiple streamtube model for studying vertical-axis wind turbines. J. Propul. Power 4 (4), 360377.CrossRefGoogle Scholar
Roshko, A. 1955 On the wake and drag of bluff bodies. J. Aeronaut. Sci. 22 (2), 124132.CrossRefGoogle Scholar
Roshko, A. 1993 Perspectives on bluff body aerodynamics. J. Wind Engng Ind. Aerodyn. 49, 79100.CrossRefGoogle Scholar
Ross, H. & Polagye, B. 2020 An experimental assessment of analytical blockage corrections for turbines. J. Renew. Energy 152, 13281341.CrossRefGoogle Scholar
Steiros, K. & Hultmark, M. 2018 Drag on flat plates of arbitrary porosity. J. Fluid Mech. 853, R3.CrossRefGoogle Scholar
Taddei, S., Manes, C. & Ganapathisubramani, B. 2016 Characterisation of drag and wake properties of canopy patches immersed in turbulent boundary layers. J. Fluid Mech. 798, 2749.CrossRefGoogle Scholar
Taylor, G. I. 1944 Air resistance of a flat plate of very porous material. Aero. Res. Counc. R & M no. 2236.Google Scholar
Werle, M. J. 2010 Wind turbine wall-blockage performance corrections. J. Propul. Power 26 (6), 13171321.CrossRefGoogle Scholar