Characterizations of force and pressure fluctuations on real vehicles

Olivier Cadot 1 A Courbois 1 D Ricot 2 Tony Ruiz 3 F Harambat 3 V Herbert 3 R Vigneron 4 J Délery 4
1 UME - Unité de Mécanique
2 Technocentre Renault [Guyancourt]
3 PSA - PSA Peugeot - Citroën
4 GIE S2A - Groupement d’Intérêt Economique Souffleries Aéroacoustiques Automobiles
Abstract : Both the unsteady aerodynamics force and base pressure distributions are investigated for four model cars in real flow conditions. The low pass cutoff frequency of the measurements is about 5 Hz which is sufficient to consider the global fluctuations of drag, lift and side forces. The drag fluctuations are very low, they never exceed 1% of the mean drag. A clear correlation is found with the base pressure distribution fluctuations. It is found that the regions of smallest pressure fluctuations on the vehicle base are the most correlated to the drag fluctuations or in other words, the regions of largest pressure fluctuations on the base are not associated with the drag fluctuations. Sideslip effect is studied, and one of the model presented a clear bistable behavior on the lift creating huge fluctuations as investigated in the academic experiment of Grandemange, Gohlke and Cadot, Physics of Fluids 25 (2013) 095103.
Keywords : road vehicle aerodynamics separated flows three-dimensionnal wake dynamics bistability full-scale experiments drag sources
Document type :
Journal articles
Complete list of metadatas

Cited literature [8 references]  Display  Hide  Download
https://hal-ensta-paris.archives-ouvertes.fr//hal-01249013
Contributor : Olivier Cadot <>
Submitted on : Tuesday, December 29, 2015 - 7:21:33 PM
Last modification on : Wednesday, July 3, 2019 - 11:48:06 AM
Long-term archiving on : Wednesday, March 30, 2016 - 11:11:31 AM

File

CNRT_unsteady_car_models.pdf
Files produced by the author(s)

Identifiers

  • HAL Id : hal-01249013, version 1

Collections

ENSTA | ENSTA_UME | UNIV-PARIS-SACLAY

Citation

Olivier Cadot, A Courbois, D Ricot, Tony Ruiz, F Harambat, et al.. Characterizations of force and pressure fluctuations on real vehicles. International Journal of Engineering Systems Modelling and Simulation, Inderscience, 2016, 8 (2), pp.99-105. ⟨hal-01249013⟩

Export

BibTeX TEI DC DCterms EndNote

Share

Metrics

Record views

190

Files downloads

820

Contact

CCSD