The force generation mechanism of lifting surfaces with flow separation ✩

Ignazio Maria Viola, Abel Arredondo-galeana, Gabriele Pisetta

Research output: Contribution to journalArticlepeer-review

Abstract / Description of output

Fins, wings, blades and sails can generate lift and drag in both attached and separated flow conditions. However, the common understanding of the lift generation mechanism holds only for attached flow conditions. In fact, when massive flow separation occurs, the underlying assumptions of thin airfoil theory and lifting line theory are violated and the concept of bound circulation cannot be applied. Therefore, there is a need to develop an intuitive understanding of the force generation mechanism that does not rely on these assumptions. This paper aims to address this issue by proposing a paradigm based on established concepts in theoretical fluid mechanics, and impulse theory in particular. The force generation can be intuitively associated with the vorticity field, which can be gathered with computational fluid dynamics or particle image velocimetry. This paradigm reconciles key known results about wing aerodynamics, and provides designers of lifting surfaces a measurable objective to optimise the shape in separated flow conditions. It will hopefully underpin both a deeper understanding of how lift and drag are generated, and the development of low order models in different fields of application.
Original languageUndefined/Unknown
Pages (from-to)109749
Number of pages1
JournalOcean Engineering
Volume239
Early online date15 Sept 2021
DOIs
Publication statusPublished - 1 Nov 2021

Keywords / Materials (for Non-textual outputs)

  • Hydrofoil/blade hydrodynamics
  • Impulse theory
  • Leading-edge separation
  • Lifting surface
  • Lifting-line theory
  • Wing/sail aerodynamics
  • Vortex Flow of Downwind Sails

    Arredondo-Galeana, A., Babinsky, H. & Viola, I. M., 22 Feb 2023, (E-pub ahead of print) In: Flow. 3, E8.

    Research output: Contribution to journalArticlepeer-review

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