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Remeshing for Rotation in CFX via ICEMCFD

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Old   September 2, 2017, 11:37
Default Remeshing for Rotation in CFX via ICEMCFD
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Dear All,
Could anyone please help me to make remeshing for rotation in ANSYS CFX through ICEMCFD.
I know how to do it for linear motion, but I would like to understand how to do remeshing for rotation. In order to do linear motion of a body with remeshing I use two scripts:

1st script looks like this:
Code:
set MeshFile {*.mesh}
set MeshReplayFile {*.rpl}
set ICEMCFDInst {C:/Program Files/ANSYS Inc/v145/icemcfd/win64_amd}
set ResFile {*/res}
set GeomFile {*.tin}
set ScalarParam(ICEM\ CFD\ Geometry\ Scale) 1.00000000e+000
set GeomCtrlFile {*/icemcfd_GeomCtrl.rpl}
set Displacement(INTER_CUBE) {0.430043637752533 0.430043637752533 0.430043548345566}

The last two lines are the most important:
“set GeomCtrlFile {*/icemcfd_GeomCtrl.rpl}” shows path to the rpl-script for ICEM CFD.
“set Displacement(INTER_CUBE) {0.430043637752533 0.430043637752533 0.430043548345566}” says that we need to do displacement.
Question #1: how to change command “Displacement” to rotation? Do I need just to write “Rotation”? For rotation, it is necessary to define axis and rotation origin.

Script “icemcfd_GeomCtrl.rpl” looks like this:
Code:
# ICEM CFD geometry update script

# Set geometry scaling factor based on Scalar Parameter
if [info exists ScalarParam(ICEM\ CFD\ Geometry\ Scale)] {
  set geoscale $ScalarParam(ICEM\ CFD\ Geometry\ Scale);
} else {
  set geoscale 1.0;
}
mess "Geometry scale for ICEM CFD: $geoscale \n";

# Loop over all moving parts
foreach part [array names Displacement] {
  for {set i 0} {$i < 3} {incr i} {set disp($i) [expr [lindex $Displacement($part) $i] / $geoscale ]};
  mess "Motion displacements for part $part: $disp(0) $disp(1) $disp(2) \n";
  set offset(0) 0;
  set offset(1) 0;
  set offset(2) 0;
  if { [info exists ScalarParam(OFFSET\ X\ $part)] } {set offset(0) [expr $ScalarParam(OFFSET\ X\ $part) / $geoscale ]};
  if { [info exists ScalarParam(OFFSET\ Y\ $part)] } {set offset(1) [expr $ScalarParam(OFFSET\ Y\ $part) / $geoscale ]};
  if { [info exists ScalarParam(OFFSET\ Z\ $part)] } {set offset(2) [expr $ScalarParam(OFFSET\ Z\ $part) / $geoscale ]};
  mess "Motion offsets for part $part: $offset(0) $offset(1) $offset(2) \n";
  set disp(0) [expr $disp(0) + $offset(0)];
  set disp(1) [expr $disp(1) + $offset(1)];
  set disp(2) [expr $disp(2) + $offset(2)];
  mess "Move part $part: $disp(0) $disp(1) $disp(2) \n";
  set item [ic_geo_get_objects surface $part ];
  if {[llength $item] > 0} {
    ic_move_geometry surface names $item translate "$disp(0) $disp(1) $disp(2)";
    mess "Part $part: move surfaces\n"};
  set item [ic_geo_get_objects curve $part ];
  if {[llength $item] > 0} {
    ic_move_geometry curve names $item translate "$disp(0) $disp(1) $disp(2)";
    mess "Part $part: move curves\n"};
  set item [ic_geo_get_objects point $part ];
  if {[llength $item] > 0} {
    ic_move_geometry point names $item translate "$disp(0) $disp(1) $disp(2)";
    mess "Part $part: move points\n"};
  set item [ic_geo_get_objects body $part ];
  if {[llength $item] > 0} {
    ic_move_geometry body names $item translate "$disp(0) $disp(1) $disp(2)";
    mess "Part $part: move bodies\n"};
}
As you can see there is the command “displacement”.
Question #2: What should I write in order to make rotation?

As a result of all actions, I should have a body that rotates. At each time step, mesh must be reconstructed automatically (remeshing). Sliding interfaces should not be considered.

Any other options to make rotation are also welcome.


Thank you!
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Old   September 2, 2017, 13:55
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Isn't it just the same problem, only instead of linear displacement you have circumferential displacement described in two axis by something like:

x=-sin(omega*t)
y=cos(omega*t)

Where omega is your rotational speed and t is simulation time.
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Old   September 4, 2017, 01:01
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Quote:
Originally Posted by gera View Post
Could anyone please help me to make remeshing for rotation in ANSYS CFX through ICEMCFD. I know how to do it for linear motion [...]
What you are describing looks like ICEM Replay Resmeshing and it only works for translation and not rotation (according to the manual). I would consider going for User Defined Remeshing instead. A bit more scripting, but way more flexible. See the reference guide.
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Old   September 23, 2017, 12:29
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Dear JuPa,
thank you for your answer. I also thought in this way. However, it was necessary to change the command "displacement" or to apply it for each cell, which is a separate domain.

Dear Lance,
thank you for the answer. User Defined Remeshing looks good alternative (the only one).
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