A 3D numerical simulation based on the lattice Boltzmann method is carried out on a simplified car geometry (initially proposed by Ahmed, Ramm, and Falting, 1984, SAE Technical Paper series No. 840300) to analyze and establish a method for controlling the near-wake flow topology of a generic blunt body model. The results indicate the existence of a complex flow topology consisting of transverse and longitudinal vortices emanating from flow separations that occur on the top and the lateral edges of the slanted rear window, respectively. The topology of each structure is detailed and the numerical results are compared with the experimental results in the literature. The results presented in this paper can then be used to develop and parametrize active control solutions conducive to improving the aerodynamic performances of automobile vehicles.

1.
Gad-El-Hak
,
M.
, 1996, “
Modern Developments in Flow Control
,”
Appl. Mech. Rev.
0003-6900,
9
, pp.
365
379
.
2.
Gilliéron
,
P.
, 2002, “
Contrôle des Écoulements Appliqués à l’Automobile. Etat de l’Art
,”
Mécanique & Industries
,
3
, pp.
515
524
.
3.
Hucho
,
W. H.
, 1998, “
Aerodynamics of Road Vehicle
,”
Annu. Rev. Fluid Mech.
0066-4189,
25
, pp.
485
537
.
4.
Ivanic
,
T.
, and
Gilliéron
,
P.
, 2004, “
Reduction of the Aerodynamic Drag Due to Cooling System: An Analytical and Experimental Approach
,” SAE Paper No. 2005-01-1017.
5.
Tensi
,
J.
,
Boué
,
I.
, and
Paillé
,
F.
, 1999, “
Effets Comparés sur L’écoulement Autour d’un Cylindre a Faible Nombre de Reynolds d’un Soufflage Pariétal Amont et en aval du Décollement
,”
14eme Congrès Français de Mécanique
,
Toulouse, France
.
6.
Ahmed
,
S. R.
,
Ramm
,
R.
, and
Falting
,
G.
, 1984, “
Some Salient Features of the Time Averaged Ground Vehicle Wake
,” SAE Technical Paper series No. 840300.
7.
Spohn
,
A.
, and
Gilliéron
,
P.
, 2002, “
Flow Separations Generated by a Simplified Geometry of an Automotive Vehicle
,”
Congrès IUTAM Symposium on Unsteady Separated Flows
,
Toulouse, France
, Apr. 8–12.
8.
Beaudoin
,
J. F.
,
Cadot
,
O.
,
Aider
,
J. L.
,
Gosse
,
K.
,
Paranthoën
,
P.
, and
Hamelin
,
B.
, 2004, “
Cavitation as a Complementary Tool for Automotive Aerodynamics
,”
Exp. Fluids
0723-4864,
37
, pp.
763
768
.
9.
Lienhart
,
H.
, and
Becker
,
S.
, 2003, “
Flow and Turbulent Structure in the Wake of a Simplified Car Model
,” SAE Paper No. 20030-01-0656.
10.
Krajnovic
,
S.
, and
Davidson
,
L.
, 2004, “
Contribution Large-Eddy Simulation of the Flow Around a Simplified Car Model
,”
SAE International Congress and Exposition
,
Detroit, MI
, Paper No. 2004-01-0227.
11.
Lehugeur
,
B.
, and
Gilliéron
,
P.
, 2005, “
Characterization of Longitudinal Vortices in the Wake of a Simplified Car Model
,” Paper No. AIAA-2005-5383.
12.
Rouméas
,
M.
, 2006, “
Contribution à l’Analyse et au Contrôle du Sillage Épais par Aspiration ou Soufflage Continu
,” Ph.D. thesis, Thèse de Doctorat, INP Toulouse, France.
13.
Frisch
,
U.
,
D’Humières
,
U.
, and
Pommeau
,
Y.
, 1986, “
Lattice-Gas Automata for Navier-Stokes Equation
,”
Phys. Rev. Lett.
0031-9007,
56
, pp.
1505
1508
.
14.
Chen
,
S.
,
Chen
,
H.
,
Martinez
,
D.
, and
Matthaeus
,
W.
, 1991, “
Lattice Boltzmann Model for Simulation of Magnetohydrodynamics
,”
Phys. Rev. Lett.
0031-9007,
67
, pp.
3776
3779
.
15.
Chen
,
S.
,
Chen
,
H.
, and
Matthaeus
,
W.
, 1992, “
Recovery of the Navier-Stokes Equations Using a Lattice-Gas Boltzmann Method
,”
Phys. Rev. A
1050-2947,
45
,
R5339
R5342
.
16.
Bhatnagar
,
P. L.
,
Gross
,
E. P.
, and
Krook
,
M.
, 1954, “
A Model for Collision Processes in Gases. Small Amplitude Processes in Charged and Neural One-Component Systems
,”
Phys. Rev.
0031-899X,
94
(
3
), pp.
511
525
.
17.
Chen
,
H.
,
Teixeira
,
C.
, and
Molvig
,
K.
, 1997, “
Digital Physics Approach to Computational Fluid Dynamics: Some Basic Theoretical Features
,”
Int. J. Mod. Phys. C
0129-1831,
8
(
4
), pp.
675
684
.
18.
Yakhot
,
V.
, and
Orszag
,
S. A.
, 1986, “
Renormalization Group Analysis of Turbulence. Basic Theory
,”
J. Sci. Comput.
0885-7474,
1
, pp.
1
51
.
19.
Pervaiz
,
M.
, and
Teixeira
,
M.
, 1999, “
Two Equation Turbulence Modeling With the Lattice-Boltzmann Method
,”
Proceedings of ASME PVP Division Conference, Second International Symposium on Computational Technologies for Fluid/Thermal and Chemical Systems With Industrial Applications
,
Boston
.
20.
Li
,
Y.
,
Shock
,
R.
,
Zhang
,
R.
, and
Chen
,
H.
, 2004, “
Numerical Study of Flow Past an Impulsively Started Cylinder by Lattice Boltzmann Method
,”
J. Fluid Mech.
0022-1120,
519
, pp.
273
300
.
21.
Shock
,
R. A.
,
Mallick
,
S.
,
Chen
,
H.
,
Yakhot
,
V.
, and
Zhang
,
R.
, 2002, “
Recent Results on Two Dimensional Airfoils Using Lattice Boltzmann-Based Algorithm
,”
J. Aircr.
0021-8669,
39
(
3
), pp.
434
439
.
22.
Gilliéron
,
P.
,
Laurent
,
J.
, and
Chometon
,
F.
, 2000, “
Analyse des Écoulements de Culot par Vélocimétrie Laser: Application à l’Automobile
,”
7ième Congrès de Vélocimétrie Laser
, September.
23.
Krajnovic
,
S.
, and
Davidson
,
L.
, 2005, “
Flow Around a Simplified Car, Part 1: Large Eddy Simulation
,”
ASME J. Fluids Eng.
0098-2202,
127
, pp.
907
918
.
24.
Krajnovic
,
S.
, and
Davidson
,
L.
, 2005, “
Flow Around a Simplified Car, Part 2: Understanding the Flow
,”
ASME J. Fluids Eng.
0098-2202,
127
, pp.
919
928
.
25.
Chen
,
H.
,
Teixeira
,
C.
, and
Molvig
,
K.
, 1998, “
Realization of Fluid Boundary Conditions via Discrete Boltzmann Dynamics
,”
Int. J. Mod. Phys. C
0129-1831,
9
(
8
), p.
1281
1292
.
26.
Yu
,
D.
,
Mai
,
R.
, and
Shyy
,
W.
, 2002, “
A Multi-Block Lattice Boltzmann Method for Viscous Fluid Flow
,”
Int. J. Numer. Methods Fluids
0271-2091,
39
, pp.
99
120
.
27.
2001,
Ninth Joint ERCOFTAC/IAHR/QNET-CFD Workshop on Refined Turbulence Modelling
,
S.
Jakirkic
,
R.
Jester-Zürker
, and
C.
Tropea
, eds.,
Darmstadt, Allemagne
.
28.
2002,
Ninth Joint ERCOFTAC/IAHR/QNET-CFD Workshop on Refined Turbulence Modeling
,
R.
Manceau
, and
J. P.
Bonnet
, eds.,
Poitiers, France
.
29.
Chassaing
,
P.
, 2000, “
Turbulence en Mécanique des Fluides: Analyse du Phénomène en vue de sa Modélisation à l’Usage de l’Ingénieur
,” CEPADUES edition, pp.
441
484
.
30.
Gilliéron
,
P.
, 1998, “
La Technique des Tomographies de Pertes de Pression d’Arrêt
,” Aérodynamique Appliquée, cycle d’approfondissement, CNAM niveau C, CNAM Médias, 1998/2001.
31.
Lehugeur
,
B.
,
Gilliéron
,
P.
, and
Ivanic
,
T.
, 2005, “
Characterization of C-Pillar Vortices by 3D PIV
,”
Workshop on Particle Image Velocimetry in Car Industry
,
Gurgliasco, Italy
.
32.
Ivanic
,
T.
,
Foucault
,
E.
, and
Pécheux
,
J.
, 2003, “
Dynamic of Swirling Jets Flows
,”
Exp. Fluids
0723-4864,
35
, pp.
317
324
.
33.
Lambourde
,
N. C.
, and
Bryer
,
D. W.
, 1961, “
The Bursting of Leading-Edge Vortices: Some Observations and Discussion of the Phenomenon
,”
Aero. Res. Counc., Report & Memoranda
,
3282
, pp.
1
35
.
34.
Gilliéron
,
P.
, and
Chometon
,
F.
, 1997, “
Modélisation de l’Écoulement Tridimensionnel Décollé Stationnaire Autours du corps de Ahmed
,” Groupe utilisateurs Fluent, Paris, Oct.
You do not currently have access to this content.