Basics : Cylinder flow
This LS-DYNA simulation shows a simple ICFD input deck with a coarse mesh. The inflow is characterized by a prescribed velocity while the reference pressure has been set to 0 for the outlet (undisturbed flow). For the far field domain, a freeslip boundary condition has been used, stipulating that the normal component of the velocity is null while the tangential is left free. For those conditions to be physically valid, they need to be put far away for the object of interest in this case the cylinder. The volume mesh is generated automatically and a boundary layer mesh has been applied to the cylinder in order to better capture the velocity gradient close to the wall.
https://www.dynaexamples.com/icfd/basics-examples/cylinder_flow
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Basics : Cylinder flow
This LS-DYNA simulation shows a simple ICFD input deck with a coarse mesh. The inflow is characterized by a prescribed velocity while the reference pressure has been set to 0 for the outlet (undisturbed flow). For the far field domain, a freeslip boundary condition has been used, stipulating that the normal component of the velocity is null while the tangential is left free. For those conditions to be physically valid, they need to be put far away for the object of interest in this case the cylinder. The volume mesh is generated automatically and a boundary layer mesh has been applied to the cylinder in order to better capture the velocity gradient close to the wall.
This LS-DYNA simulation shows a simple ICFD input deck with a coarse mesh. The inflow is characterized by a prescribed velocity while the reference pressure has been set to 0 for the outlet (undisturbed flow). For the far field domain, a freeslip boundary condition has been used, stipulating that the normal component of the velocity is null while the tangential is left free. For those conditions to be physically valid, they need to be put far away for the object of interest in this case the cylinder. The volume mesh is generated automatically and a boundary layer mesh has been applied to the cylinder in order to better capture the velocity gradient close to the wall.
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Fluid velocity fringes
*DATABASE_BINARY_D3PLOT *DEFINE_CURVE_TITLE *END *ICFD_BOUNDARY_FREESLIP *ICFD_BOUNDARY_PRESCRIBED_VEL *ICFD_BOUNDARY_PRESCRIBED_PRE *ICFD_BOUNDARY_NONSLIP *ICFD_CONTROL_TIME *ICFD_DATABASE_DRAG *ICFD_MAT *ICFD_PART *ICFD_PART_VOL *ICFD_SECTION *INCLUDE *KEYWORD *MESH_BL *MESH_SURFACE_ELEMENT *MESH_SURFACE_NODE *MESH_VOLUME *PARAMETER *TITLE
$-----------------------------------------------------------------------------
$
$ Example provided by Iñaki (LSTC)
$
$ E-Mail: info@dynamore.de
$ Web: http://www.dynamore.de
$
$ Copyright, 2015 DYNAmore GmbH
$ Copying for non-commercial usage allowed if
$ copy bears this notice completely.
$
$X------------------------------------------------------------------------------
$X
$X 1. Run file as is.
$X Requires LS-DYNA MPP R8.0.0 (or higher) with double precision
$X
$X------------------------------------------------------------------------------
$# UNITS: Dimensionless.
$X------------------------------------------------------------------------------
$X
*KEYWORD
*TITLE
ICFD Cylinder flow
*INCLUDE
mesh.k
$---+----1----+----2----+----3----+----4----+----5----+----6----+----7----+----8
$ $
$ PARAMETERS $
$ $
$---+----1----+----2----+----3----+----4----+----5----+----6----+----7----+----8
*PARAMETER
R T_end 100.0
R dt_plot 1.00
$
$--- Fluid
$
R v_inlet 1.0
Rrho_fluid 1.0
R mu_fluid 0.005
R dt_fluid 0.000
$
$---+----1----+----2----+----3----+----4----+----5----+----6----+----7----+----8
$ $
$ ICFD CONTROL CARDS $
$ $
$---+----1----+----2----+----3----+----4----+----5----+----6----+----7----+----8
*ICFD_CONTROL_TIME
$# ttm dt
&T_end &dt_fluid
$---+----1----+----2----+----3----+----4----+----5----+----6----+----7----+----8
$ $
$ ICFD PARTS/ SECTION/ MATERIAL $
$ $
$---+----1----+----2----+----3----+----4----+----5----+----6----+----7----+----8
*ICFD_SECTION
$# sid
1
*ICFD_MAT
$# mid flg ro vis
1 1&rho_fluid &mu_fluid
*ICFD_PART
$# pid secid mid
1 1 1
*ICFD_PART
$# pid secid mid
2 1 1
*ICFD_PART
$# pid secid mid
3 1 1
*ICFD_PART
$# pid secid mid
4 1 1
*ICFD_PART_VOL
$# pid secid mid
10 1 1
$# spid1 spid2 spid3 spid4
1 2 3 4
$---+----1----+----2----+----3----+----4----+----5----+----6----+----7----+----8
$ $
$ ICFD BOUNDARY/INITIAL CONDITIONS $
$ $
$---+----1----+----2----+----3----+----4----+----5----+----6----+----7----+----8
*ICFD_BOUNDARY_PRESCRIBED_VEL
$# pid dof vad lcid
1 1 1 1
*ICFD_BOUNDARY_PRESCRIBED_VEL
$# pid dof vad lcid
1 2 1 2
*ICFD_BOUNDARY_PRESCRIBED_PRE
$# pid lcid sf death birth
2 2
*ICFD_BOUNDARY_FREESLIP
$# pid
3
*ICFD_BOUNDARY_NONSLIP
$# pid
4
*DEFINE_CURVE_TITLE
Velocity inlet
$# lcid sidr sfa sfo offa offo dattyp
1 &v_inlet
$# a1 o1
0.0 1.0
10000.0 1.0
*DEFINE_CURVE_TITLE
Pressure outlet
$# lcid sidr sfa sfo offa offo dattyp
2
$# a1 o1
0.0 0.0
10000.0 0.0
$---+----1----+----2----+----3----+----4----+----5----+----6----+----7----+----8
$ $
$ ICFD MESH KEYWORDS $
$ $
$---+----1----+----2----+----3----+----4----+----5----+----6----+----7----+----8
*MESH_VOLUME
$# volid
1
$# pid1 pid2 pid3 pid4
1 2 3 4
*MESH_BL
$# pid nelth
4 2
$---+----1----+----2----+----3----+----4----+----5----+----6----+----7----+----8
$ $
$ DATABASE (OUTPUT) $
$ $
$---+----1----+----2----+----3----+----4----+----5----+----6----+----7----+----8
*ICFD_DATABASE_DRAG
$# pid
4
*DATABASE_BINARY_D3PLOT
&dt_plot
*END