This content is not included in
your SAE MOBILUS subscription, or you are not logged in.
Aerodynamic Investigation of Vehicle Cooling-Drag
Technical Paper
2012-01-0170
ISSN: 0148-7191, e-ISSN: 2688-3627
Annotation ability available
Sector:
Language:
English
Abstract
The interaction between cooling-air and external aerodynamics is known as interference. In a conventional car this interference under the hood results in additional drag. It is estimated that about 10% of the overall aerodynamic drag originates from the cooling air [1] depending on the car shape and cooling configuration. Obviously, cooling drag should be minimized for vehicles with low-drag aerodynamics. In this study cooling-air interference-effects are investigated through experimental, numerical and analytical methods with a focus on the surface pressure of the vehicle. The surface pressure of vehicles with and without interference effects is compared. Observations show that when the cooling-air inlet is opened a pressure rise occurs around the inlet, while a pressure drop appears around the outlet. This phenomenon was investigated for several vehicle shapes including a simplified bluff-body (SAE-Body) and a close-to-real quarter-scale model (aeromodel). Using this knowledge, a cooling duct with low cooling drag was investigated. It will be shown that the cooling drag decreases when the air is redirected appropriately, yet the pressure increase at the front of the vehicles cannot be avoided.
Recommended Content
Authors
Topic
Citation
Baeder, D., Indinger, T., Adams, N., and Unterlechner, P., "Aerodynamic Investigation of Vehicle Cooling-Drag," SAE Technical Paper 2012-01-0170, 2012, https://doi.org/10.4271/2012-01-0170.Also In
References
- Kuthada, T. Die Optimierung von PKW-Kühlluftführungssystemen unter dem Einfluss moderner Bodensimulationstechniken Dissertation Universität Stuttgart; Expert Verlag 2006
- Soja, H. Wiedemann, J. The Interference between Exterior and Interior Flow on Road Vehicles Dynamique du véhicule 1987
- Williams, J. “Aerodynamic Drag of Engine-Cooling Airflow with External Interference,” SAE Technical Paper 2003-01-0996 2003 10.4271/2003-01-0996
- Wolf, T. Minimising the Cooling System Drag for the New Porsche 911 Carrera 5 MIRA International Conference Warwick, UK 2004
- Wolf, T. Minimising the Cooling System Drag for the New Porsche 011 Carrera Euro Motor Lecture Series Vehicle Aerodynamics and Aeroacoustics 2005
- Wolf, T. Preiss, M. Auslegung widerstamdsarmer Kühlluftkonzepte am Beispiel des neuen Porsche 911 Carrera Tagung “Aerodynamik des Kraftfahrzeuges” Haus der Technik Essen 2004
- Barnard, R. H. Bullen, P. R. Qiao, J. Fixed and Variable Cooling Outlet Geometries for the Minimisation of Associated Drag 5 th MIRA International Conference Warwick, UK 2004
- Jehle, E. Strömungsstrukturerkennung auf der Basis von numerischen 3D Navier-Stokes-Simulationen zur Einbindung in den Fahrzeugentwicklungsprozess Dissertation Fakultät für Maschinenbau, Universität Karlsruhe (TH) 2001
- Kuthada, T. Pfannkuchen, E. Wiedemann, J. Evaluation of Cooling Air Drag on a Reference Body 5 th MIRA International Conference Warwick, UK 2004
- SAE International Surface Vehicle Recommended Practice “Aerodynamic Testing of Road Vehicles - Open Throat Wind Tunnel Adjustment,” SAE Standard J2071 June 1994
- Tesch, G. Demuth, R. Adams, N. A. “A New Approach to Analyzing Cooling and Interference Drag,” SAE Int. J. Passeng. Cars -Mech Syst. 3 1 339 351 2010 10.4271/2010-01-0286
- Bäeder, D. Indinger, T. Adams, N. A. Decker, F. “Comparison of Numerical Simulations with Experiments of Bluff Bodies including Under-Hood Flow,” SAE Technical Paper 2011-01-0171 2011 10.4271/2011-01-0171
- Kickinger, F. Tools for the Numerical Simulation of 3D Magnetic Field Problems Construction, Analysis and C++ Implementation Trauner Verlag 1996
- Kickinger, F. Automatic Microscaling Multielement Mesh Generation Institutsreport Universität Linz Institut für Mathematik 1997
- Kickinger, F. Parallel Mesh Generation for large scale applications using hexdominant meshes Proceedings ASIM 2005 S133ff 2005
- Lutz, T. Flugzeug- und Flugkörperaerodynamik 2007
- Lutz, T. Profilentwurf 2007
- Tietjens, O. Strömungslehre Springer 1 1960
- Tietjens, O. Strömungslehre Springer 2 1970
- Wagner, S. Vorlesung Strömungslehre 7 2006