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Alternative Approach in Ground Vehicle Wake Analysis
Abstract:In this paper an alternative visualisation approach of the wake behind different vehicle body shapes with simplified and fully-detailed underbody has been proposed and analysed. This allows for a more clear distinction among the different wake regions. This visualisation is based on a transformation of the cartesian coordinates of a chosen wake plane to polar coordinates, using as filter velocities lower than the freestream. This transformation produces a polar wake plot that enables the division and quantification of the wake in a number of sections. In this paper, local drag has been used to visualise the drag contribution of the flow by the different sections. Visually, a balanced wake can be observed by the concentric behaviour of the polar plots. Alternatively, integration of the local drag of each degree section as a ratio of the total local drag yields a quantifiable approach of the wake uniformity, where different sections contribute equally to the local drag, with the exception of the wheels.
Digital Object Identifier (DOI): doi.org/10.5281/zenodo.1329220Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 1923
 W.H. Hucho, Aerodynamics of Road Vehicles, 4rd ed., United States of America, 1998.
 E.C. Maskell, Progress Towards A Method For The Measurement Of The Components Of The Drag Of A Wing Of Finite Span, Royal Aircraft Technical Report, 72232, January 1973.
 J.C. Wu, J.E. Hackett and D.E. Lilley, A Generalized Wake-Integral Approach for Drag Determination in Three-Dimensional Flows, AIAA Paper No. 79-0279, New Orleans, January 1979.
 S.R. Ahmed, Wake Structures of Typical Automobile Shapes, ASME Journal of Fluids Engineering, Volume 103 (March 1981), Issue 1, pp. 162-169.
 M. Onorato, A.F. Costelli and A. Garonne, Drag Measurements Through Wake Analysis, SAE 840302, SAE International Congress and Exposition, Detroit, 1984.
 J.E. Hackett and A. Sugavanam, Evaluation of a Complete Wake Integral for the Drag of a Car-Like Shape, SAE 840302, SAE International Congress and Exposition, Detroit, 1984.
 S.R. Ahmed, G.Ramm and G. Faltin, Some Salient Features Of The Time-Averaged Ground Vehicle Wake, 840300, SAE International Congress and Exposition, Detroit, USA, 1984.
 A. Cogotti, A Strategy For Optimum Surveys of Passenger-Car Flow Field, SAE 890374, SAE International Congress and Exposition, Detroit, USA, 1989.
 A. Morelli, A New Aerodynamic Approach to Advanced Automobile Basic Shapes, 2000-01-0491, SAE World Congress, Detroit, USA, 2000.
 P. Elofsson, Drag Reduction Mechanisms Due to Moving Ground and Wheel Rotation in Passenger Cars, 2002-01-0531, SAE World Congress, Detroit, USA, 2000.
 T. Ivanić and P. Gilliéron, Aerodynamic Drag And Ways To Reduce It, Lecture Series 2005-05, Road Vehicle Aerodynamics, von Karman Institute for Fluid Dynamics, Brussels, Belgium, 2005.
 P.B.V. Johansson and W.K. George, The Far Downstream Evolution Of The High Reynolds Number Axisymmetric Wake Behind A Disk, Journal of Fluid Mechanics, Volume 255, pp. 363-385, 2006.
 J. Howell, The Decay of Bluff Body Wakes, 2011-01-0178, SAE World Congress, Detroit, USA, 2011.