Besides the monolithic thermal coupling method, it is also possible to trigger a weak/loose explicit method between the structure and the fluid. The choice between the two methods can be made using ICFD_CONTROL_CONJ. This method may offer an alternative for lower computational time but a finer mesh may be necessary to achieve the same level of accuracy especially in the wall region. Similarly, the thermal and fluid timesteps may be independent but it is recommended to keep them close in highly non linear configurations. Regardless of the chosen coupling method, it is also possible to extract the heat transfer coefficient at the interface using ICFD_DATABASE_HTC. The user is encouraged to switch between the two coupling methods and compare.
Fluid velocity fringes
*KEYWORD *TITLE *CONTROL_TERMINATION *CONTROL_THERMAL_TIMESTEP *CONTROL_THERMAL_SOLVER *CONTROL_TIMESTEP *CONTROL_SOLUTION *DATABASE_BINARY_D3PLOT *DEFINE_CURVE_TITLE *ELEMENT_SHELL *ICFD_BOUNDARY_FREESLIP *ICFD_BOUNDARY_FSI *ICFD_BOUNDARY_PRESCRIBED_VEL *ICFD_BOUNDARY_PRESCRIBED_PRE *ICFD_BOUNDARY_NONSLIP *ICFD_CONTROL_CONJ *ICFD_CONTROL_FSI *ICFD_CONTROL_TIME *ICFD_CONTROL_OUTPUT *ICFD_DATABASE_DRAG *ICFD_DATABASE_TEMP *ICFD_DATABASE_HTC *ICFD_INITIAL *ICFD_MAT *ICFD_PART *ICFD_PART_VOL *ICFD_SECTION *INCLUDE *INITIAL_TEMPERATURE_SET *MAT *MESH_BL *MESH_BL_SYM *MESH_SURFACE_ELEMENT *MESH_SURFACE_NODE *MESH_VOLUME *NODE *PARAMETER *PART *SECTION *END
$-----------------------------------------------------------------------------
$
$ 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 Dev svn 112000 (or higher) with double precision
$X
$X------------------------------------------------------------------------------
$# UNITS: Dimensionless.
$X------------------------------------------------------------------------------
$X
*KEYWORD
*TITLE
ICFD Weak thermal coupling
*INCLUDE
mesh.k
*INCLUDE
struc.k
$---+----1----+----2----+----3----+----4----+----5----+----6----+----7----+----8
$ $
$ PARAMETERS $
$ $
$---+----1----+----2----+----3----+----4----+----5----+----6----+----7----+----8
*PARAMETER
R T_end 500.0
R dt_plot 5.00
$
$--- Fluid
$
R v_inlet 0.5
Rrho_fluid 1.0
R mu_fluid 0.010
R dt_fluid 1.000
RTemp_init 60.000
RTemp_inle 65.000
R HC_fluid 1000.
R TC_fluid 200.
$
$---+----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
*ICFD_CONTROL_FSI
$# owc
1
$$ Set the following keyword to 0 to trigger strong conjugate heat transfer
*ICFD_CONTROL_CONJ
$# ctype
1
*ICFD_CONTROL_OUTPUT
$# msgl
3
$---+----1----+----2----+----3----+----4----+----5----+----6----+----7----+----8
$ $
$ ICFD PARTS/ SECTION/ MATERIAL $
$ $
$---+----1----+----2----+----3----+----4----+----5----+----6----+----7----+----8
*ICFD_SECTION
$# sid
1
*ICFD_MAT
$# mid flg ro vis
1 1&rho_fluid &mu_fluid
$# hc tc
&HC_fluid &tc_fluid
*ICFD_PART
$# pid secid mid
1 1 1
*ICFD_PART
$# pid secid mid
2 1 1
*ICFD_PART
$# pid secid mid
3 1 1
*ICFD_PART_VOL
$# pid secid mid
10 1 1
$# spid1 spid2 spid3
1 2 3
$---+----1----+----2----+----3----+----4----+----5----+----6----+----7----+----8
$ $
$ ICFD BOUNDARY/INITIAL CONDITIONS $
$ $
$---+----1----+----2----+----3----+----4----+----5----+----6----+----7----+----8
*ICFD_BOUNDARY_PRESCRIBED_VEL
$# pid dof vad lcid
1 1 1 1
*ICFD_BOUNDARY_PRESCRIBED_VEL
$# pid dof vad lcid
1 2 1 2
*ICFD_BOUNDARY_PRESCRIBED_TEMP
$# pid lcid
1 3
*ICFD_BOUNDARY_PRESCRIBED_PRE
$# pid lcid
2 2
*ICFD_BOUNDARY_NONSLIP
$# pid
3
*ICFD_BOUNDARY_FSI
$# pid
3
$$$ To be un-commented for strong Conjugate heat transfer $$$
$*ICFD_BOUNDARY_CONJ_HEAT
$$# pid
$ 3
*ICFD_INITIAL
$# pid vx vy vz temp
0 &Temp_init
*DEFINE_CURVE_TITLE
Velocity inlet
$# lcid sidr sfa sfo offa offo dattyp
1
$# a1 o1
0 &v_inlet
10000.0 &v_inlet
*DEFINE_CURVE_TITLE
Pressure outlet
$# lcid sidr sfa sfo offa offo dattyp
2
$# a1 o1
0.0 0.0
10000.0 0.0
*DEFINE_CURVE_TITLE
Temp inlet
$# lcid sidr sfa sfo offa offo dattyp
3 &Temp_inle
$# a1 o1
0.0 1.0
10000.0 1.0
$---+----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_BL
$# pid nelth
3 1
*MESH_BL_SYM
$# pid1
1
*MESH_BL_SYM
$# pid1
2
$---+----1----+----2----+----3----+----4----+----5----+----6----+----7----+----8
$ $
$ DATABASE (OUTPUT) $
$ $
$---+----1----+----2----+----3----+----4----+----5----+----6----+----7----+----8
*ICFD_DATABASE_HTC
$# out htc tb outdt
2 0 50
*ICFD_DATABASE_FLUX
$# pid
2
*ICFD_DATABASE_TEMP
$# pid
1
*ICFD_DATABASE_TEMP
$# pid
2
*ICFD_DATABASE_TEMP
$# pid
3
*DATABASE_BINARY_D3PLOT
$# dt
&dt_plot
*END
Besides the monolithic thermal coupling method, it is also possible to trigger a weak/loose explicit method between the structure and the fluid. The choice between the two methods can be made using ICFD_CONTROL_CONJ. This method may offer an alternative for lower computational time but a finer mesh may be necessary to achieve the same level of accuracy especially in the wall region. Similarly, the thermal and fluid timesteps may be independent but it is recommended to keep them close in highly non linear configurations. Regardless of the chosen coupling method, it is also possible to extract the heat transfer coefficient at the interface using ICFD_DATABASE_HTC. The user is encouraged to switch between the two coupling methods and compare.