We perform three-dimensional particle resolved direct numerical simulations of the flow past a non-spherical obstacle by a Finite Volume cut-cell method, a sub-class of non-body-conforming methods that provides a sharp description of the boundary, which is strictly mass and momentum conservative and can be easily extended to adaptive grids. The present research work discusses the effect of corner rounding and the incidence angle for a range of Reynolds numbers for which the flow exhibits a steady-state behavior. The obstacle is placed in a large cubic domain that properly models an unbounded domain. Hierarchically refined Cartesian meshes are used where the obstacle resides at the finest level of the mesh hierarchy, thus ensuring that the resolution of the boundary layer and the wake of the obstacle is highly accurate, along with significantly reducing the number of grid cells and the computing time. Specifically, we characterize the drag force and the main features of the flow past a bluff obstacle transitioning in shape from spherical to cuboidal through a superquadric geometrical representation. A superquadric representation is suitable for our study since it preserves geometric isometry, and our analysis, thus, focusses on non-sphericity caused by the level of curvature. We investigate a range of Re from 10 to 150, which spans the flow from attached to symmetric and separated past five different obstacle shapes, with the corner radius of the curvature of r/a=2/ζi=1,2/2.5,2/4,2/8 and 0 placed at incidence angles of α=0°,15°,30°, and 45° with respect to the streamwise direction. In general, our results show that the obstacle bluffness increases with α and ζi and this increase is more prominent at higher Re. Higher drag forces are a consequence of either higher viscous forces for more streamlined bodies and in less inertial regimes or higher pressure forces for more bluff bodies and in highly inertial regimes, depending on how the corners are contributing to the frontal and lateral surface areas.

1.
A.
Wachs
, “
Particle-scale computational approaches to model dry and saturated granular flows of non-Brownian, non-cohesive, and non-spherical rigid bodies
,”
Acta Mech.
230
,
1919
1980
(
2019
).
2.
S.
Tenneti
and
S.
Subramaniam
, “
Particle-resolved direct numerical simulation for gas-solid flow model development
,”
Annu. Rev. Fluid Mech.
46
,
199
230
(
2014
).
3.
R.
Clift
and
W. H.
Gauvin
, “
Motion of entrained particles in gas streams
,”
Can. J. Chem. Eng.
49
,
439
448
(
1971
).
4.
L.
Schiller
and
Z.
Naumann
, “
A drag coefficient correlation
,”
Z. Ver. Dtsch. Ing.
77
(
318
),
318
320
(
1935
).
5.
T. A.
Johnson
and
V. C.
Patel
, “
Flow past a sphere up to a Reynolds number of 300
,”
J. Fluid Mech.
378
,
19
70
(
1999
).
6.
A. G.
Tomboulides
and
S. A.
Orszag
, “
Numerical investigation of transitional and weak turbulent flow past a sphere
,”
J. Fluid Mech.
416
,
45
73
(
2000
).
7.
R.
Beetstra
,
M. A.
van der Hoef
, and
J. A. M.
Kuipers
, “
Drag force of intermediate Reynolds number flow past mono- and bidisperse arrays of spheres
,”
AIChE J.
53
(
2
),
489
501
(
2007
).
8.
B.
Pier
, “
Local and global instabilities in the wake of a sphere
,”
J. Fluid Mech.
603
,
39
61
(
2008
).
9.
X.
Yin
and
S.
Sundaresan
, “
Fluid-particle drag in low-Reynolds-number polydisperse gas-solid suspensions
,”
AIChE J.
55
,
1352
1368
(
2009
).
10.
S.
Tenneti
,
R.
Garg
, and
S.
Subramaniam
, “
Drag law for monodisperse gas–solid systems using particle-resolved direct numerical simulation of flow past fixed assemblies of spheres
,”
Int. J. Multiphase Flow
37
,
1072
1092
(
2011
).
11.
G.
Bagheri
and
C.
Bonadonna
, “
On the drag of freely falling non-spherical particles
,”
Powder Technol.
301
,
526
544
(
2016
).
12.
P.
Shi
and
R.
Rzehak
, “
Lift forces on solid spherical particles in unbounded flows
,”
Chem. Eng. Sci.
208
,
115145
(
2019
).
13.
F.
Zafar
and
M. M.
Alam
, “
Flow structure around and heat transfer from cylinders modified from square to circular
,”
Phys. Fluids
31
,
083604
(
2019
).
14.
M.
Zastawny
,
G.
Mallouppas
,
F.
Zhao
, and
B.
van Wachem
, “
Derivation of drag and lift force and torque coefficients for non-spherical particles in flows
,”
Int. J. Multiphase Flow
39
,
227
239
(
2012
).
15.
A.
Richter
and
P. A.
Nikrityuk
, “
Drag forces and heat transfer coefficients for spherical, cuboidal and ellipsoidal particles in cross flow at sub-critical Reynolds numbers
,”
Int. J. Heat Mass Transfer
55
,
1343
1354
(
2012
).
16.
A.
Richter
and
P. A.
Nikrityuk
, “
New correlations for heat and fluid flow past ellipsoidal and cubic particles at different angles of attack
,”
Powder Technol.
249
,
463
474
(
2013
).
17.
R.
Ouchene
,
M.
Khalij
,
B.
Arcen
, and
A.
Taniere
, “
A new set of correlations of drag, lift and torque coefficients for non-spherical particles and large Reynolds numbers
,”
Powder Technol.
303
,
33
43
(
2016
).
18.
J.
Gan
,
Z.
Zhou
, and
A.
Yu
, “
CFD-DEM modeling of gas fluidization of fine ellipsoidal particles
,”
Part. Technol. Fluidization
62
,
62
77
(
2016
).
19.
L.
He
,
D. K.
Tafti
, and
K.
Nagendra
, “
Evaluation of drag correlations using particle resolved simulations of spheres and ellipsoids in assembly
,”
Powder Technol.
313
,
332
343
(
2017
).
20.
H. I.
Andersson
and
F.
Jiang
, “
Forces and torques on a prolate spheroid: Low-Reynolds-number and attack angle effects
,”
Acta Mech.
230
,
431
447
(
2019
).
21.
K.
Frohlich
,
M.
Meinke
, and
W.
Schroder
, “
Correlations for inclined prolates based on highly resolved simulations
,”
J. Fluid Mech.
901
,
A5
(
2020
).
22.
X.
Li
,
M.
Jiang
,
Z.
Huang
, and
Q.
Zhou
, “
Effect of particle orientation on the drag force in random arrays of oblate ellipsoids in low-Reynolds-number flows
,”
AIChE J.
65
(
8
),
e16621
(
2019
).
23.
A. K.
Saha
, “
Three-dimensional numerical simulations of the transition of flow past a cube
,”
Phys. Fluids
16
,
1630
1646
(
2004
).
24.
A.
Saha
, “
Three-dimensional numerical study of flow and heat transfer from a cube placed in a uniform flow
,”
Int. J. Heat Fluid Flow
27
,
80
94
(
2006
).
25.
A.
Holzer
and
M.
Sommerfeld
, “
New simple correlation formula for the drag coefficient of non-spherical particles
,”
Powder Technol.
184
,
361
365
(
2008
).
26.
M. H.
Khan
,
P.
Sooraj
,
A.
Sharma
, and
A.
Agrawal
, “
Flow around a cube for Reynolds numbers between 500 and 55,000
,”
Exp. Therm. Fluid Sci.
93
,
257
271
(
2018
).
27.
J.
Hilton
,
L.
Mason
, and
P.
Cleary
, “
Dynamics of gas–solid fluidised beds with non-spherical particle geometry
,”
Chem. Eng. Sci.
65
,
1584
1596
(
2010
).
28.
Y.
Chen
and
C.
Muller
, “
Development of a drag force correlation for assemblies of cubic particles: The effect of solid volume fraction and Reynolds number
,”
Chem. Eng. Sci.
192
,
1157
1166
(
2018
).
29.
A.
Seyed-Ahmadi
and
A.
Wachs
, “
Sedimentation of inertial monodisperse suspensions of cubes and spheres
,”
Phys. Rev. Fluids
6
(
4
),
044306
(
2021
).
30.
J.
Davidson
, “
Multiscale modeling and simulation of crosslinked polymers
,” Ph.D. thesis (
University of Michigan
,
2014
).
31.
W.
Zhang
and
R.
Samtaney
, “
Low-re flow past an isolated cylinder with rounded corners
,”
Comput. Fluids
136
,
384
401
(
2016
).
32.
P.
Dey
and
A. K. R.
Das
, “
A numerical study on effect of corner radius and Reynolds number on fluid flow over a square cylinder
,”
Sādhanā
42
,
1155
1165
(
2017
).
33.
T.
Ambreen
and
M.-H.
Kim
, “
Flow and heat transfer characteristics over a square cylinder with corner modifications
,”
Int. J. Heat Mass Transfer
117
,
50
57
(
2018
).
34.
S.
Miran
and
C. H.
Sohn
, “
Numerical study of the rounded corners effect on flow past a square cylinder
,”
Int. J. Numer. Methods Heat Fluid Flow
25
,
686
702
(
2015
).
35.
S.
Miran
and
C. H.
Sohn
, “
Influence of incidence angle on the aerodynamic characteristics of square cylinders with rounded corners
,”
Int. J. Numer. Methods Heat Fluid Flow
26
,
269
283
(
2016
).
36.
M. M.
Alam
,
T.
Abdelhamid
, and
A.
Sohankar
, “
Effect of cylinder corner radius and attack angle on heat transfer and flow topology
,”
Int. J. Mech. Sci.
175
,
105566
(
2020
).
37.
Y.
Wang
,
Z.
Hu
, and
D.
Thompson
, “
Numerical investigations on the flow over cubes with rounded corners and the noise emitted
,”
Comput. Fluids
202
,
104521
(
2020
).
38.
J. B.
Bell
,
P.
Colella
, and
H. M.
Glaz
, “
A second-order projection method for the incompressible Navier-Stokes equations
,”
J. Comput. Phys.
85
(
2
),
257
283
(
1989
).
39.
A.
Jaklic
and
F.
Solina
, “
Moments of superellipsoids and their application to range image registration
,”
IEEE Trans. Syst., Man, Cybern., Part B.
33
,
648
657
(
2003
).
40.
R.
Trunk
,
C.
Bretl
,
G.
Thater
,
H.
Nirschl
,
M.
Dorn
, and
M. J.
Krause
, “
A study on shape-dependent settling of single particles with equal volume using surface resolved simulations
,”
Computation
9
,
40
(
2021
).
41.
A. J.
Chorin
, “
On the convergence of discrete approximations to the Navier-Stokes equations
,”
Math. Comput.
23
(
106
),
341
353
(
1969
).
42.
S.
Popinet
, “
An accurate adaptive solver for surface-tension-driven interfacial flows
,”
J. Comput. Phys.
228
(
16
),
5838
5866
(
2009
).
43.
S.
Popinet
, “
A quadtree–adaptive multigrid solver for the Serre–Green–Naghdi equations
,”
J. Comput. Phys.
302
,
336
358
(
2015
).
44.
S.
Popinet
, “
Gerris: A tree-based adaptive solver for the incompressible Euler equations in complex geometries
,”
J. Comput. Phys.
190
(
2
),
572
600
(
2003
).
45.
A. R.
Ghigo
, “
A conservative finite volume cut-cell method on an adaptive Cartesian tree grid for moving rigid bodies in incompressible flows
”; available at http://basilisk.fr/sandbox/ghigo/README
46.
P.
Colella
,
D. T.
Graves
,
B. J.
Keen
, and
D.
Modiano
, “
A Cartesian grid embedded boundary method for hyperbolic conservation laws
,”
J. Comput. Phys.
211
(
1
),
347
366
(
2006
).
47.
H.
Johansen
and
P.
Colella
, “
A Cartesian grid embedded boundary method for Poisson's equation on irregular domains
,”
J. Comput. Phys.
147
(
1
),
60
85
(
1998
).
48.
P.
Schwartz
,
M.
Barad
,
P.
Colella
, and
T.
Ligocki
, “
A Cartesian grid embedded boundary method for the heat equation and Poisson's equation in three dimensions
,”
J. Comput. Phys.
211
(
2
),
531
550
(
2006
).
49.
J. A.
van Hooft
,
S.
Popinet
,
C. C.
van Heerwaarden
,
S. J.
van der Linden
,
S. R.
de Roode
, and
B. J.
van de Wiel
, “
Towards adaptive grids for atmospheric boundary–layer simulations
,”
Boundary-Layer Meteorol.
167
(
3
),
421
443
(
2018
).
50.
J.
López-Herrera
,
S.
Popinet
, and
A.
Castrejón-Pita
, “
An adaptive solver for viscoelastic incompressible two-phase problems applied to the study of the splashing of weakly viscoelastic droplets
,”
J. Non-Newtonian Fluid Mech.
264
,
144
158
(
2019
).
51.
S.
Popinet
, “
Basilisk flow solver and PDE library
”; available at available at http://basilisk.fr/
52.
J. A.
van Hooft
, “
The grid adaptation algorithm based on a wavelet-estimated discretization error
”; available at http://basilisk.fr/sandbox/Antoonvh/The_adaptive_wavelet_algirthm
53.
C.
Selçuk
,
A. R.
Ghigo
,
S.
Popinet
, and
A.
Wachs
, “
A fictitious domain method with distributed Lagrange multipliers on adaptive quad/octrees for the direct numerical simulation of particle-laden flows
,”
J. Comput. Phys.
430
,
109954
(
2021
).
54.
H. J.
Wang
and
L.
Cheng
, “
Flow separation around a square cylinder at low to moderate Reynolds numbers
,”
Phys. Fluids
32
,
044103
(
2020
).
55.
D.
Kumar
,
K.
Sourav
,
P. K.
Yadav
, and
S.
Sen
, “
Understanding the secondary separation from an inclined square cylinder with sharp and rounded trailing edges
,”
Phys. Fluids
31
,
073607
(
2019
).
56.
G.
Akiki
,
T.
Jackson
, and
S.
Balachandar
, “
Pairwise interaction extended point-particle model for a random array of monodisperse spheres
,”
J. Fluid Mech.
813
,
882
928
(
2017
).
57.
W.
Moore
,
S.
Balachandar
, and
G.
Akiki
, “
A hybrid point-particle force model that combines physical and data-driven approaches
,”
J. Comput. Phys.
385
,
187
208
(
2019
).
58.
A.
Seyed-Ahmadi
and
A.
Wachs
, “
Microstructure-informed probability-driven point-particle model for hydrodynamic forces and torques in particle-laden flows
,”
J. Fluid Mech.
900
,
A21
(
2020
).
59.
A.
Seyed-Ahmadi
and
A.
Wachs
, “
Physics-inspired architecture for neural network modeling of forces and torques in particle-laden flows
,”
Comput. Fluids
238
,
105379
(
2022
).
You do not currently have access to this content.