Detached-eddy simulation (DES) is used to study the massively separated flow over a rounded-corner square. The configuration is an idealization of the flow around a forebody cross section rotating at high angle of attack. Simulations are performed at sub- and supercritical Reynolds numbers, between which experimental measurements show a reversal of the side force. DES predictions are evaluated using experimental measurements and contrasted with unsteady Reynolds-averaged Navier–Stokes (URANS) results. The computations are also subjected to a moderate grid refinement, a doubling of the spanwise period, an enlargement of the domain in the other directions, and the removal of any explicit turbulence model. The sub- and supercritical flows are computed at Reynolds numbers of $105$ and $8×105$, respectively, and with the freestream at $10deg$ angle of attack. Boundary-layer separation characteristics (laminar or turbulent) are established via the initial and boundary conditions of the eddy viscosity. Following boundary layer detachment, a chaotic and three-dimensional wake rapidly develops. For the supercritical flow, the pressure distribution is close to the measured values and both the streamwise and side forces are in adequate agreement with measurements. For the subcritical flow, DES side-force predictions do not follow the experimental measurements far enough to achieve reversal.

1.
Travin
,
A.
,
Shur
,
M.
,
Strelets
,
M.
, and
Spalart
,
P.
, 2001, “
Detached-Eddy Simulations past a Circular Cylinder
,”
Flow, Turbul. Combust.
1386-6184,
63
, pp.
293
313
.
2.
Durbin
,
P. A.
, 1995, “
Separated flow computations using the k-ϵ-v2 model
,”
AIAA J.
0001-1452,
33
,
4
, p.
659
.
3.
Shur
,
M.
,
Spalart
,
P. R.
,
Squires
,
K. D.
,
Strelets
,
M.
, and
Travin
,
A.
, “
The Persistence and Effects of Three-dimensionality in Unsteady RANS Simulations of Two-dimensional Bluff Bodies
,”
AIAA J.
0001-1452 (to be published).
4.
Spalart
,
P. R.
,
Jou
,
W.-H.
,
Strelets
,
M.
, and
Allmaras
,
S. R.
, 1997, “
Comments on the Feasibility of LES for Wings, and on a Hybrid RANS/LES Approach
,”
Advances in DNS/LES, 1st AFOSR Int. Conference on DNS/LES
, 4–8 Aug.
Greyden Press
,
Columbus
, OH.
5.
Spalart
,
P. R.
, and
Allmaras
,
S. R.
, 1994, “
A One-Equation Turbulence Model for Aerodynamic Flows
,”
Rech. Aerosp.
0034-1223,
1
, p.
5
.
6.
Spalart
,
P. R.
, 2000, “
Strategies for Turbulence Modelling and Simulations
,”
Int. J. Heat Fluid Flow
0142-727X,
21
, pp.
252
263
.
7.
Constantinescu
,
S. G.
, and
Squires
,
K. D.
, 2004, “
Numerical Investigations of Flow over a Sphere in the Subcritical and Supercritical Regimes
,”
Phys. Fluids
1070-6631,
16
, pp.
1449
1466
.
8.
Forsythe
,
J. R.
,
Squires
,
K. D.
,
Wurtzler
,
K. E.
, and
Spalart
,
P. R.
, 2004, “
Detached-Eddy Simulation of the F-15E at High Alpha
,”
J. Aircr.
0021-8669,
41
, pp.
193
200
.
9.
Mittal
,
R.
, and
Moin
,
P.
, 1997, “
Suitability of Upwind-Biased Finite Difference Schemes for Large-Eddy Simulation of Turbulent Flows
,”
AIAA J.
0001-1452,
35
, pp.
1415
1417
.
10.
Polhamus
,
E. C.
,
Geller
,
E. W.
, and
Grunwald
,
K. J.
, 1959, “
Pressure and Force Characteristics of Noncircular Cylinders as Affected by Reynolds Number with a Method Included for Determining the Potential Flow about Arbitrary Shapes
,” NASA TR R-46.
11.
Shur
,
M.
,
Spalart
,
P. R.
,
Strelets
,
M.
, and
Travin
,
A.
, 1999, “
Detached-Eddy Simulation of an Airfoil at High Angle of Attack
,”
4th Int. Symp. Eng. Turb. Modelling and Measurements
,
Corsica
, 24–26, May.
12.
Strang
,
W. Z.
,
Tomaro
,
R. F.
, and
Grismer
,
M. J.
, 1999, “
The Defining Methods of COBALT60: A Parallel, Implicit, Unstructured Euler/Navier–Stokes Flow Solver
,” AIAA 99-0786.
13.
Gottlieb
,
J. J.
, and
Groth
,
C. P. T.
, 1988, “
Assessment of Riemann Solvers for Unsteady One-Dimensional Inviscid Flows of Perfect Gases
,”
J. Comput. Phys.
0021-9991,
78
, pp.
437
458
.
14.
Karypis
,
G.
,
Schloegel
,
K.
, and
Kumar
,
V.
, 1997, “
PARMETIS: Parallel Graph Partitioning and Sparse Matrix Ordering Library Version 1.0
,”
University of Minnesota
, Department of Computer Science, Minneapolis, MN.
15.
Hsu
,
K.
, and
Lee
,
S. L.
, 1991, “
A Numerical Technique for Two-Dimensional Grid Generation with Grid Control at All of the Boundaries
,”
J. Comput. Phys.
0021-9991,
11
, pp.
451
469
.
16.
Steinbrenner
,
J.
,
Wyman
,
N.
, and
Chawner
,
J.
, 2000, “
Development and Implementation of Gridgen’s Hyperbolic PDE and Extrusion Methods
,” AIAA 00-0679.
17.
Morton
,
S. A.
,
Forsythe
,
J. R.
,
Mitchell
,
A.
, and
Hajek
,
D.
, 2002, “
Detached-Eddy Simulations and Reynolds-Averaged Navier-Stokes Simulations of Delta Wing Vortical Flowfields
,”
ASME J. Fluids Eng.
0098-2202,
124
, pp.
924
932
.