This paper presents experimental flow control results obtained on a full-scale production car in a wind tunnel. The aim of this paper is to demonstrate the feasibility of controlling the separated flow over the rear part of the car by using pulsed micro-jets. Pulsed micro-jets are produced by hybrid actuators mixing both standard and MEMS (Micro Electro Mechanical Systems) technology. Both actuation frequency and injected momentum are studied. Experiments show a small influence on the drag force (less than 1% reduction), but a stronger one on the lift force (up to 9% reduction). Wall pressure coefficients measurements highlight the suppression of the recirculation bubble over the rear window, along with a reinforcement of the longitudinal C-pillars vortices. Spectral measurements in the shear layer above the rear window show that most efficient control frequencies match the shear layer instability frequency, and that the actuation suppresses the energetical contribution associated with the recirculation bubble frequency. Additional measurements demonstrate that a minimum threshold value of the momentum coefficient is needed for the flow actuation to be efficient. This is the first experimental evidence of the efficiency of micro perturbations (380μm thick micro-nozzles) to control flow separation on a full- scale production car. This is a very important step in the perspective of future applications of flow control in automotive industry to improve aerodynamics performances and reduce CO2 emissions.
Active flow control using pulsed micro-jets on a full-scale production car
Jean-Luc AiderRelated information
1 Laboratoire PMMH, UMR7636 CNRS, ESPCI ParisTech, 10 rue Vauquelin, 75231 Paris, FRANCE
, Pierric JosephRelated information2 Institut Aérotechnique (IAT), 15 rue Marat, 78210 Saint-Cyr-l'Ecole, FRANCE
, Tony RuizRelated information3 PSA Peugeot Citroën DRIA/DSTF/SFTA, 2 route de Gisy, 78943 Vélizy-Villacoublay Cedex, FRANCE
, Philippe GilotteRelated information4 Plastic Omnium Auto Extérieur Services (POAES), Parc Industriel de la Plaine de l'Ain, 01150 Saint-Julie, FRANCE
, Yoann EulalieRelated information4 Plastic Omnium Auto Extérieur Services (POAES), Parc Industriel de la Plaine de l'Ain, 01150 Saint-Julie, FRANCE
, Christophe EdouardRelated information5 FLOWDIT, 2 rue professeur Paul Milleret, 25000 Besançon, FRANCE
, Xavier AmandoleseRelated information6 Aerodynamics Department, CNAM, 15 rue Marat, 78210 Saint-Cyr-l'Ecole, FRANCE
Published Online: September 23, 2014
Abstract