# Basics : Plate flow — Welcome to LS-DYNA Examples

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This LS-DYNA simulation shows a simple ICFD input deck with a coarse mesh. It shows how the solver deal with infinitely thin plates or shells in 3D. Since two nodes are needed in order to solve for the pressure difference between the two faces of the plate, the automatic volume mesher will generate an extra node and ‘pull’ a little on the mesh leaving a tiny gap between them, considered infinitely small compared to the size of the problem. This is done through the introduction of the keyword MESH_EMBEDSHELL.

## Animated Result

Fluid velocity streamlines

## Keywords

```*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_EMBEDSHELL
*MESH_SURFACE_ELEMENT
*MESH_SURFACE_NODE
*MESH_VOLUME
*PARAMETER
*TITLE
```

## Reduced Input

```\$-----------------------------------------------------------------------------
\$
\$ Example provided by Iñaki (LSTC)
\$
\$ E-Mail: info@dynamore.de
\$ Web: http://www.dynamore.de
\$
\$ 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 Plate 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
1         1         1         1
*ICFD_BOUNDARY_PRESCRIBED_VEL
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
10
\$#    pid1      pid2      pid3
1         2         3
*MESH_EMBEDSHELL
\$#   volid
10
\$#    pid1
4
*MESH_BL
\$#     pid     nelth
4         1
\$---+----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```

## Description

This LS-DYNA simulation shows a simple ICFD input deck with a coarse mesh. It shows how the solver deal with infinitely thin plates or shells in 3D. Since two nodes are needed in order to solve for the pressure difference between the two faces of the plate, the automatic volume mesher will generate an extra node and ‘pull’ a little on the mesh leaving a tiny gap between them, considered infinitely small compared to the size of the problem. This is done through the introduction of the keyword MESH_EMBEDSHELL.