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Experimental and Numerical Investigations of the Base Wake on an SUV
ISSN: 0148-7191, e-ISSN: 2688-3627
Published April 08, 2013 by SAE International in United States
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With the increase in fuel prices and the increasingly strict environmental legislations regarding CO₂ emissions, reduction of the total energy consumption of our society becomes more important. Passenger vehicles are partly responsible for this consumption due to their strong presence in the daily life of most people. Therefore reducing the impact of cars on the environment can assist in decreasing the overall energy consumption. Even though several fields have an impact on a passenger car's performance, this paper will focus on the aerodynamic part and more specifically, the wake behind a vehicle.
By definition a car is a bluff body on which the air resistance is for the most part driven by pressure drag. This is caused by the wake these bodies create. Therefore analyzing the wake characteristics behind a vehicle is crucial if one would like to reduce drag. With the recent upgrade of wind tunnels with a moving belt system, the opportunity has emerged to investigate the flow field in the wake behind vehicles, matching closer the real on-road driving conditions.
This study investigates experimentally and numerically the wake behind a passenger car of an SUV type. Three configurations with a significant change in CD have been chosen for the analysis. Their wake shape together with their respective closure points have been analyzed using three planes, namely one x-plane, one y-plane and one z-plane.
Results have shown that the numerical simulations correlate well with the experiments in wake shape and wake behavior. However in the chosen configurations they underestimate the wake length. A distinct interference of the traversing unit presence can be noted in the experimental results.
CitationSterken, L., Sebben, S., Walker, T., and Lofdahl, L., "Experimental and Numerical Investigations of the Base Wake on an SUV," SAE Technical Paper 2013-01-0464, 2013, https://doi.org/10.4271/2013-01-0464.
- European Energy and Transport, EU-25 Energy and transport outlook to 2030.
- US Energy Information Administration, http://www.eia.gov/forecasts/aeo/sector_transportation_all.cfm#uses, available on 2012-10-17.
- Eurostat, European Commission, Energy statistics, http://epp.eurostat.ec.europa.eu/portal/page/portal/energy/introduction, available on 2012-10-17.
- Hucho, W.-H., “Aerodynamics of Road Vehicles,” Society of Automotive Engineers, Inc., Warrendale, PA, ISBN: 978-0-7680-0029-0.
- Ahmed, S., Ramm, G., and Faltin, G., “Some Salient Features Of The Time-Averaged Ground Vehicle Wake,” SAE Technical Paper 840300, 1984, doi:10.4271/840300.
- Cogotti, A., “Flow-Field Surveys Behind Three Squareback Car Models Using a New “Fourteen-Hole” Probe,” SAE Technical Paper 870243, 1987, doi:10.4271/870243.
- Wäschle, A., “Numerische und experimentelle Untursuchung des Einflusses von drehenden Rädern auf die Fahrzeugaerodynamik”, Expert Verlag, Renningen, Germany, 2006.
- Landström, C., “Passenger Car Wheel Aerodynamics”, Chalmers reproservice, Gothenburg, 2011.
- Wiedemann, J., “The Influence of Ground Simulation and Wheel Rotation on Aerodynamic Drag Optimization - Potential for Reducing Fuel Consumption,” SAE Technical Paper 960672, 1996, doi:10.4271/960672.
- Sternéus, J., Walker, T., and Bender, T., “Upgrade of the Volvo Cars Aerodynamic Wind Tunnel,” SAE Technical Paper 2007-01-1043, 2007, doi:10.4271/2007-01-1043.
- Aeroprobe, Online Omniprobe Documentation, http://www.aeroprobe.com/uploads/Aeroprobe-Omniprobe-Information-2012.pdf, available on 2012-10-17
- Mercker, E., Cooper, K., Fischer, O., and Wiedemann, J., “The Influence of a Horizontal Pressure Distribution on Aerodynamic Drag in Open and Closed Wind Tunnels,” SAE Technical Paper 2005-01-0867, 2005, doi:10.4271/2005-01-0867.
- Sebben, S. and Mlinaric, P., “Investigation of the Influence of Tyre Deflection and Tyre Contact Patch on CFD Predictions of Aerodynamic Forces on a Passenger Car”, 7th MIRA International Vehicle Aerodynamics Conference, October 2008.
- Cogotti, A., “A Strategy for Optimum Surveys of Passenger-Car Flow Fields,” SAE Technical Paper 890374, 1989, doi:10.4271/890374.
- Ivanic T. Gilliéron P., “Aerodynamic drag and ways to reduce it”, Lecture Series VKI Institute, Brussels, 2005.
- Sterken L. Sebben S. Löfdahl L., “Alternative Approach in Ground Vehicle Wake Analysis”, WASET ICAME, Oslo, 2012.