This content is not included in
your SAE MOBILUS subscription, or you are not logged in.
Experimental Investigations of Vehicle Base Drag Reduction Using Passive Jet Boat-Tail Flow Control
Technical Paper
2014-01-2448
ISSN: 0148-7191, e-ISSN: 2688-3627
Annotation ability available
Sector:
Language:
English
Abstract
This study is focused on the detailed experimental investigation of jet boat-tail (JBT) passive flow control bluff body models to reduce the base pressure drag. The JBT technique is employed through an open inlet at the leading edge of the bluff body along with a circumferential jet at the trailing edge in order to energize the base flow using the high kinetic energy flow from freestream. As a consequence, entrainment of the main flow into base flow region is initiated earlier downstream. A reduction in the turbulent fluctuation of the wake can be observed in addition to a decrease of the recirculation region velocity. Using 2D/3C Particle Image Velocimetry (PIV), two models with different inlet sizes are tested. The large flow rate model is designed with an inlet area 4.7 times greater than the other JBT prototype. The wind tunnel experimental results show a substantial reduction in the wake width and depth for the two models, which indicates a significant drag reduction. Moreover, mean velocity vector plots from PIV measurements at the mid-plane location suggest their flow fields differ significantly due to the nature of the passive jets employed. The Jet1 model initiates the large coherent structures and flow entrainment earlier than the baseline model even though the jet momentum is small. The Jet2 generates paired vortices in the shear layer due to the high jet momentum and entrain main flow to the base region. The experimentation is performed at a Reynolds number of Re = 2.55×105. In order to investigate the effects at higher Reynolds numbers, Computational Fluid Dynamics (CFD) is used to model the flows using Large Eddy Simulation, which shows that the drag reduction is more effective at high Reynolds number.
Recommended Content
Technical Paper | On the Calculation of External Aerodynamics: Industrial Benchmarks |
Technical Paper | The DaimlerChrysler Full-Scale Aeroacoustic Wind Tunnel |
Technical Paper | A CFD and Experimental Study of an Ahmed Reference Model |
Authors
Citation
Bartow, W., Moreyra, A., Hirst, T., Woyczynski, G. et al., "Experimental Investigations of Vehicle Base Drag Reduction Using Passive Jet Boat-Tail Flow Control," SAE Technical Paper 2014-01-2448, 2014, https://doi.org/10.4271/2014-01-2448.Also In
References
- Hucho W. H. Aerodynamik des Automobils Wieweg+ Teubner fifth 2005
- Drollinger , R. , Heavy Duty Truck Aerodynamics SAE Technical Paper 870001 1987 10.4271/870001
- Buresti , G. and Iungo , G. V. and Lombardi , G. Methods for The Drag Reduction of Bluff Bodies and Their Application to Heavy Road-Vehicles 1st Interim Report Contract between CRF and DIA, DDIA 2007-6 Oct. 2007
- Storms , B. L. and Satran , D. R. and Heineck , J. T. and Walker , M. A Summary of the Experimental Results for aGeneric Tractor-Trailer in the Ames Research Center 7- by 10-Foot and 12-Foot Wind Tunnels NASA/TM2006-213489 2006
- Diamond , S. , Heavy Vehicle Systems Optimization 2004 Annual Progress Report Feb 2005
- Tanner , M. , Reduction of Base Drag Prog. Aerospace Sci. 16 4 369384 1975
- Maull , D. J. and Hoole B. J. , The effect of boat-tailing on the flow around a two-dimensional blunt-basedaerofoil at zero incidence J. Royal Aero. Soc. 71 854858 1967
- McCallen , R. DOEs Effort to reduce truck aerodynamic drag through joint experiments and computations Presentation at the DOE Heavy Vehicle Systems Optimization Merit Review and Peer Evaluation Argonne National Laboratory April 18-20 2006
- Berman , P. W. Investigation into the effect of base bleed on the flow behind a two-dimensional model with a blunt trailing edge AGARD CP-4 2 485 507 1966
- Zha , G.-C. Low Noise and Low Drag Automobile Mirrors Using Jet Flow Control UMM-115 University of Miami Invention Disclosure Sept. 7 2012
- Zha , G.-C. Low Noise Low Drag Automobile Mirrors Provisional Patent filed to USPTO,61/765,219, 02/15/2013 2013
- Zha , G.-C. Low Drag Low Noise Automobile Mirrors Using Jet Flow Control Patent Coorperation Treaty, PCT/US2013/053191, filed to USPTO, 08/01/2013 2013
- Zha , G.-C. Low Drag Low Noise Device Using Jet Flow Control Utility Patent filed to USPTO on 02/14/2014, 14/180,460
- Wang , J. , Bartow , W. , Moreyra , A. , Woyczynski , G. et al. Low Drag Automotive Mirrors Using Passive Jet Flow Control SAE Int. J. Passeng. Cars - Mech. Syst. 7 2 2014 10.4271/2014-01-0584
- Engineering Laboratory Design, INC. Model 406 http://www.eldinc.com/pages/Model406/ 2009
- Kirk , D. , Experimental and Numerical Investigations of a High Performance Co-Flow Jet Airfoil Masters Thesis Mechanical Engineering Department, University of Miami Coral Gables 2009
- Litron Lasers Lasers for PIV Applications http://www.litronlasers.com/pdf%20files/LitronPIVProducts0109_1.pdf
- International Towing Tank Conference Recommended Procedures and Guidelines Uncertainty Analysis Particle Imaging Velocimetry Sept. 2008
- Anderson , J.D. Fundamentals of Aerodynamics McGraw-Hill Boston 0-07-339810-1 2001
- Wu , J.Z. , Ma , H.Y. , Zhou , M.D. , Vorticity and Vortex Dynamics Springer 2006 Berlin
- Shen , Y.-Q. and Zha , G.-C. and Chen , X.-Y. High Order Conservative Differencing for Viscous Terms and the Application to Vortex-Induced Vibration Flows Journal of Computational Physics 228 2 82838300 2009
- Roe , P. Approximate Riemann Solvers, Parameter Vectors, and Difference Schemes Journal fo Computational Physics 1981
- Shen , Y.-Q. and Zha , G.-C. and Wang , B.-Y. Improvement of Stability and Accuracy of Implicit WENO Schem AIAA Journal 47 2 331 344 2009