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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
*
[email protected]
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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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