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Effect on drag of the flow orientation at the base separation of a simplified blunt road vehicle

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Abstract

The separated flow past the square-back model used in the experiments of Ahmed et al. (1984) is controlled using flaps at the end of the top and bottom faces. A parametric study of the flow regarding the slant angle of the flaps is performed from pressure and force measurements as well as particle image velocimetry. When the bottom flap orientation is fixed, variations in the top slant angle indicate a quadratic dependence of drag versus lift. This relationship presents self-similarities when modifying the bottom flap angle. It is furthermore observed that the lift is an affine function of both slant angles and the drag is a second-order polynomial containing a coupling term between the two angles. The evolution of the drag, depending on both angles, is discussed. The contribution of the wake size, lift-induced drag as well as the local drag induced by the inclination of the flaps is interpreted.

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Authors and Affiliations

  1. Unité de Mécanique, Ecole Nationale Supérieure de Techniques Avancées, ParisTech, 828 Boulevard des Maréchaux, 91762, Palaiseau Cedex, France

    M. Grandemange & O. Cadot

  2. PSA Peugeot Citroën, Centre Technique de Velizy, Route de Gisy, 78943, Vélizy-Villacoublay Cedex, France

    M. Grandemange, A. Mary & M. Gohlke

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  1. M. Grandemange
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  2. A. Mary
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  3. M. Gohlke
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  4. O. Cadot
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Correspondence to M. Grandemange.

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Grandemange, M., Mary, A., Gohlke, M. et al. Effect on drag of the flow orientation at the base separation of a simplified blunt road vehicle. Exp Fluids 54, 1529 (2013). https://doi.org/10.1007/s00348-013-1529-z

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  • DOI: https://doi.org/10.1007/s00348-013-1529-z

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