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Inverse lift: a signature of the elasticity of complex fluids?

Benjamin Dollet·Miguel Aubouy·Francois Graner
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Abstract

To understand the mechanics of a complex fluid such as a foam we propose a model experiment (a bidimensional flow around an obstacle) for which an external sollicitation is applied, and a local response is measured, simultaneously. We observe that an asymmetric obstacle (cambered airfoil profile) experiences a downards lift, opposite to the lift usually known (in a different context) in aerodynamics. Correlations of velocity, deformations and pressure fields yield a clear explanation of this inverse lift, involving the elasticity of the foam. We argue that such an inverse lift is likely common to complex fluids with elasticity.

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Benjamin Dollet, Miguel Aubouy, Francois Graner. 2005-02-15. Inverse lift: a signature of the elasticity of complex fluids?. https://doi.org/10.1103/physrevlett.95.168303

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