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Techniques for Aerodynamic Analysis of Cornering Vehicles
ISSN: 0148-7191, e-ISSN: 2688-3627
Published March 10, 2015 by SAE International in United States
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When a vehicle travels through a corner it can experience a significant change in aerodynamic performance due to the curved path of its motion. The yaw angle of the flow will vary along its length and the relative velocity of the flow will increase with distance from the central axis of its rotation. Aerodynamic analysis of vehicles in the cornering condition is an important design parameter, particularly in motorsport. Most racing-cars are designed to produce downforce that will compromise straight-line speed to allow large gains to be made in the corners. Despite the cornering condition being important, aerodynamicists are restricted in their ability to replicate the condition experimentally. Whirling arms, rotary rigs, curved test sections and bent wind tunnel models are experimental techniques capable of replicating some aspects of the cornering condition, but are all compromised solutions.
Numerical simulation is not limited in the same way and permits investigation into the condition. However, cornering introduces significant change to the flowfield and this must be accommodated for in several ways. Boundary conditions are required to be adapted to allow for the curved flow occurring within a non-inertial reference frame. In addition, drag begins to act in a curved path and variation in Re occurs within the domain. Results highlight the importance of using correct analysis techniques when evaluating aerodynamic performance for cornering vehicles.
CitationKeogh, J., Barber, T., Diasinos, S., and Doig, G., "Techniques for Aerodynamic Analysis of Cornering Vehicles," SAE Technical Paper 2015-01-0022, 2015, https://doi.org/10.4271/2015-01-0022.
- Milliken, W., and Milliken, D., “Race Car Vehicle Dynamics” (Warrendale, Society of Automotive Engineers, Inc., 1994), ISBN 978-1-56091-526-3.
- Dominy RG. Aerodynamics of Grand Prix Car Proc. Inst. Mech. Eng. 1992; 206:267-274.
- Katz J. Aerodynamics of Race Cars. Annu. Rev. Fluid Mech. 2006; 38:27-63. doi:10.1146/annurev.fluid.38.050304.092016.
- Zhang X, Toet W and Zerihan J. Ground Effect Aerodynamics of Race Cars. Appl. Mech. Rev. 2006; 59:33-49. doi:10.1115/1.2110263.
- Toet W. Aerodynamics and aerodynamic research in Formula 1. Aeronaut. J. 2013; 117(1187):1-26.
- Tsubokura, M., Ikawa, Y., Nakashima, T., Okada, Y. et al., “Unsteady Vehicle Aerodynamics during a Dynamic Steering Action: 2nd Report, Numerical Analysis,” SAE Int. J. Passeng. Cars - Mech. Syst. 5(1):340-357, 2012, doi:10.4271/2012-01-0448.
- Okada, Y., Nouzawa, T., Okamoto, S., Fujita, T. et al., “Unsteady Vehicle Aerodynamics during a Dynamic Steering Action: 1st Report, On-Road Analysis,” SAE Technical Paper 2012-01-0446, 2012, doi:10.4271/2012-01-0446.
- Nara, K., Tsubokura, M., Ikeda, J., Fasel, U., et. al “Numerical Analysis of Unsteady Aerodynamics of Formula Car during Dynamic Cornering Motion,” 32nd AIAA Applied Aerodynamics Conference, June 2014, Atlanta, GA, USA
- Curtis, H., Putman, W. and Traybar, J., “The Princeton Dynamic Model Track,” Aerodynamic Testing Conference, Washington D.C., USA, 1964 doi:10.2514/6.1964-1104.
- Baals, D. and Corliss, W., Wind Tunnels of NASA, NASA accessed October 30, 2014. http://www.hq.nasa.gov/pao/History/SP-440/contents.htm
- Mulkens, M. and Ormerod, A., “Steady-State Experiments for Measurements of Aerodynamic Stability Derivatives of a High Incidence Research Model Using the College of Aeronautics Whirling Arm,” College of Aeronautics Report No. 9014, 1990
- Llewelyn-Davies, M. “The Redesign of the College of Aeronautics Whirling Arm Facility”, College of Aeronautics Report No. 8702, 1987
- Kumar, P. “The College of Aeronautics Whirling Arm Initial Development Tests,” CoA Note Aero. No. 174, 1967
- Gili, P. and Battipede, M., “Experimental Validation of the Wing Dihedral Effect Using a Whirling Arm Experiment,” J. Aircraft 2001; 38(6):1069-1075. doi:10.2514/2.2874
- Ericsson, E., “Reflections Regarding Recent Rotary Rig Results,” J. Aircraft 1987; 24(1): 25-30. doi:10.2514/3.45406
- Pattison, J., Lowenberg, M. and Goman, M., “Multi-Degree-of-Freedom Wind-Tunnel Maneuver Rig for Dynamic Simulation and Aerodynamic Model Identification,” J. Aircraft 2013;50(2):551-566. doi:10.2514/1.C031924
- Aschwanden, P., Müller, J., Travaglio, G., and Schöning, T., “The Influence of Motion Aerodynamics on the Simulation of Vehicle Dynamics,” SAE Int. J. Passeng. Cars - Mech. Syst. 1(1):545-551, 2009, doi:10.4271/2008-01-0657.
- Duell, E., Kharazi, A., Muller, S., Ebeling, W. et al., “The BMW AVZ Wind Tunnel Center,” SAE Technical Paper 2010-01-0118, 2010, doi:10.4271/2010-01-0118.
- “Stability Tunnel,” last modified July 8, 2014, http://crgis.ndc.nasa.gov/historic/Stability_Tunnel
- Berger, S., Talbot, L. and Yao, L., “Flow in Curved Pipes” Ann. Rev. Fluid Mech. 1983. 15:461-512
- Gordes A. Process for simulating curved airflow on wheeled vehicles in fluid channels with a straight measuring section Patent No. EP1610111A2, Germany, 2005.
- Gregory, P., Joubert, P. and Chong, M., Flow Over a Body of Revolution in a Steady Turn, Australia: DSTO Platforms Sciences Library, 2004
- 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.
- Keogh J, Doig G, Diasinos S, and Barber T, “Detached Eddy Simulation of the Cornering Aerodynamics of the Ahmed Reference Model” FISITA World Automotive Conference, Maastricht, the Netherlands, June 2014