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Ferrofluid thin films for aerofoil lift enhancement and delaying flow separation

Published online by Cambridge University Press:  18 August 2020

F.J. Arias
F.J. Arias*
Affiliation:
Department of Fluid Mechanics, Polytechnic University of Catalonia, ESEIAAT C/Colom 11, 08222 Barcelona, Spain
*
francisco.javier.arias@upc.edu
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Abstract

In this work, consideration is given to a novel concept for aerofoil lift enhancement and delaying flow separation. Here, lift enhancement is attained by preventing the growth of the boundary layer through the elimination of the zero-slip condition between the wing surface and the air stream. The concept would simulate all the effects of a moving wall, leading to the appearance of a slip velocity at the gas–fluid interface, including the injection of momentum into the air boundary layer, but with one exception: here there is no moving wall but instead a ferrofluid thin film pumped parallel and attached to the wall by a magnetic field. Utilising a simplified physical model for the velocity profile of the ferrofluid film and based on ferrohydrodynamic stability considerations, an analytical expression for the interfacial velocity is derived. Finally, from the available experimental data on moving walls, the expected lift and angle-of-attack enhancement are found as well as the weight penalty per unit surface area of the wing is estimated. Additional research and development is required to explore the possibilities of using ferrofluid thin films.

Keywords

Flow separationBoundary layerLift enhancementAerodynamics
Type
Research Article
Information
The Aeronautical Journal , Volume 124 , Issue 1282 , December 2020 , pp. 1865 - 1878
Copyright
© The Author(s), 2020. Published by Cambridge University Press on behalf of Royal Aeronautical Society

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References

REFERENCES

Modi, V.J. Moving surface boundary-layer control: a review, J. Fluid Struct., 1997, 11, pp 627–663.CrossRefGoogle Scholar
Hammer, P., Visbal, M., Naguib, A. and Koochesfahani, M. Lift on a steady 2-D symmetric airfoil in viscous uniform shear flow, J. Fluid Mech., 2018, 837, R2.CrossRefGoogle Scholar
Fernandez-Feria, R. and Alaminos-Quesada, J. Unsteady thrust, lift and moment of a two-dimensional flapping thin airfoil in the presence of leading-edge vortices: a first approximation from linear potential theory, J. Fluid Mech., 2018, 851, pp 344–373.CrossRefGoogle Scholar
Panda, J. and Zaman, K. Experimental investigation of the flow field of an oscillating airfoil and estimation of lift from wake surveys, J. Fluid Mech., 1994, 265, pp 65–95. doi: 10.1017/S0022112094000765CrossRefGoogle Scholar
Bhat, S., Zhao, J., Sheridan, J., Hourigan, K. and Thompson, M. Evolutionary shape optimisation enhances the lift coefficient of rotating wing geometries, J. Fluid Mech., 2019, 868, pp 369–384.CrossRefGoogle Scholar
Yeh, C. and Taira, K. Resolvent-analysis-based design of airfoil separation control, J. Fluid Mech., 2019, 867, pp 572–610.Google Scholar
Gao, W., Zhang, W., Cheng, W. and Samtaney, R. Wall-modelled large-eddy simulation of turbulent flow past airfoils, J. Fluid Mech., 2019, 873, pp 174–210.Google Scholar
Wang, S., He, G. and Liu, T. Estimating lift from wake velocity data in flapping flight, J. Fluid Mech., 2019, 868, pp 501–537.CrossRefGoogle Scholar
Ringuette, M.J., Milano, M. and Gharib, M. Role of the tip vortex in the force generation of low-aspect-ratio normal flat plates, J. Fluid Mech., 2007, 581, pp 453–468.CrossRefGoogle Scholar
Gilarranz, J., Traub, L. and Rediniotis, O. A new class of synthetic jet actuators-part II: application to flow separation control, Trans. ASME-I J. Fluid Eng., 2005, 127, (2), p 377.CrossRefGoogle Scholar
Rosenweig, R.E. Ferrohydrodynamics, Dover, 1985, Mineola, NY.Google Scholar
Landau, L.D. and Lifshitz, E.M. Fluid Mechanics, 2nd ed, Pergamon Press, 1989.Google Scholar
Bateman, H. Partial Differential Equations of Mathematical Physics, Cambridge University Press, 1932, Cambridge, UK, p. 175.Google Scholar
Boukenkoul, M.A., Li, F.-C., Chen, W.-L. and Zhang, H.-N. Lift-generation and moving-wall flow control over a low aspect ratio airfoil. J. Fluid Eng., 2018, 140, (1), p. 011104.CrossRefGoogle Scholar