City Car Drag Reduction by Means of Shape Optimization and Add-On Devices

  • A. Ferraris
  • A. G. Airale
  • D. Berti Polato
  • A. Messana
  • S. Xu
  • P. Massai
  • M. CarelloEmail author
Conference paper
Part of the Mechanisms and Machine Science book series (Mechan. Machine Science, volume 73)


In recent years, the automotive industry has moved its attention to green technologies, investing in high efficiency engines, lightweight materials, and low-rolling-resistance tires. Under these circumstances car body styling and aerodynamics play an important role in reducing vehicle drag force, permitting an improvement in fuel and energy efficiency. The objective of this study is the reduction of a city-car prototype’s aerodynamic resistance by means of standard aerodynamic devices (i.e. spoiler, finlets, rear underbody, front bumper, rear dam and wheel cover). This work starts with a CFD analysis performed on the baseline configuration of the XAM 2.0 (eXtreme Automotive Mobility) vehicle, whose critical areas are then considered for the aerodynamic improvement. A CFD analysis of vehicle aerodynamics is performed in order to design different add-on features to be manufactured and tested in Pininfarina Wind tunnel. A final correlation between virtual and experimental results is carried out, validating the drag reduction, demonstrating the predictive capabilities of CFD analysis.


Aerodynamic Features Wind Tunnel Test CFD Drag Reduction City Car 


Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.



Special thanks to the hard work of all the Aerodynamics group, especially to Andrea Serra and to Beta-CAE, Star-CCM+ and Pininfarina for their support.


  1. 1.
    Altaf A, Omar AA, Asrar W (2014) Passive drag reduction of square back road vehicles. Journal of Wind Engineering and Industrial Aerodynamics 134: 30-43.
  2. 2.
    Barlow JB, Guterres R, Ranzenbach R (2001) Experimental parametric study of rectangular bodies with radiused edges in ground effect. Journal of Wind Engineering and Industrial Aerodynamics 89(14-15): 1291-1309.
  3. 3.
    Barnard RH (2001) Road vehicle aerodynamic design: an introduction. Mechaero, Hertfordshire. OCLC: 802928257Google Scholar
  4. 4.
    Blocken B, Toparlar Y (2015) A following car inuences cyclist drag: CFD simulations and wind tunnel measurements. 145:178-186.
  5. 5.
    Carello M, Serra A, Airale, AG, Ferraris A (2015) Design the City vehicle XAM using CFD Analysis. SAE World Congress, Detroit 21-23 April, pp. 7.
  6. 6.
    Celik I (2005) RANS/LES/DES/DNS: The Future Prospects of Turbulence Modeling. Journal of Fluids Engineering 127(5): 829.
  7. 7.
    Cogotti A (1995) Ground effect simulation for full-scale cars in the pininfarina wind tunnel.
  8. 8.
    Cogotti A (2007) The new moving ground system of the pininfarina wind tunnel.
  9. 9.
    Commission, E.U. (2014) Commission delegated regulation (EU) no 44/2014 of 21 November 2013 supplementing regulation (EU) no 168/2013 of the European parliament and of the council with regard to the vehicle construction and general requirements for the approval of two- or three-wheel vehicles and quadricycles text with EEA relevance. Official Journal of the European Union.Google Scholar
  10. 10.
    Guilmineau E (2008) Computational study of flow around a simplified car body. Journal of Wind Engineering and Industrial Aerodynamics 96(6-7): 1207-1217.
  11. 11.
    Guilmineau E (2014) Numerical Simulations of Flow around a Realistic Generic Car Model. SAE International Journal of Passenger Cars - Mechanical Systems 7(2): 646-653.Google Scholar
  12. 12.
    Shenkel in the book of Lance MH (2012) The shape of green: aesthetics, ecology, and design. pp 37Google Scholar
  13. 13.
    International SAE (2010) j1594 vehicle aerodynamics terminology.Google Scholar
  14. 14.
    Schuetz T (2016) Aerodynamics of road vehicles.Google Scholar
  15. 15.
    Thacker A, Aubrun S, Leroy A, Devinant P (2012) Effects of suppressing the 3D separation on the rear slant on the flow structures around an Ahmed body. Journal of Wind Engineering and Industrial Aerodynamics. 107-108: 237-243.
  16. 16.
    Skaperdas V, Iordanidis A (2013) The influence of mesh characteristics on CFD simulations for automotive applications. Automotive Simulation World Congress, October 29-30, Frankfurt, Germany.Google Scholar

Copyright information

© Springer Nature Switzerland AG 2019

Authors and Affiliations

  1. 1.Mechanical and Aerospace Engineering Department of Politecnico di TorinoTorinoItaly

Personalised recommendations