Constraning FFD Box movement in +Z direction

Umuteng · July 21, 2022, 14:05

Hello All,

Is it possible to constrain FFD Box deformation in a specific direction?
I mean, I want to allow the FFD Box to move in the -(negative)Z direction but not in the +(positive)Z direction.

Any help will be appreciated.
Thanks

wallym · July 25, 2022, 21:00

Hi Umuteng,

Yes. I always suggest manually creating the DEFINITION_DV field. When you do, you can specify exactly the grid deformation you want to perform -> heres part of an example from SU2's tutorials suite:

DEFINITION_DV= ( 11, 1.0 | UPPER_SIDE, LOWER_SIDE, TIP | WING, 0, 1, 0, 0.0, 0.0, 1.0 );

This FFD design variable with the FFD coordinates of (0,1,0) will only deform in the +Z directions (0.0,0.0,1.0) as defined by the last three arguments.

If you want your variables to be constrained to -Z your arguments would like:
DEFINITION_DV= ( 11, 1.0 | UPPER_SIDE, LOWER_SIDE, TIP | WING, 0, 1, 0, 0.0, 0.0, -1.0 );

Best,
Wally

July 21, 2022, 14:05	Constraning FFD Box movement in +Z direction	#1
Umuteng Member Umut Can Join Date: Oct 2012 Posts: 42 Rep Power: 13	Hello All, Is it possible to constrain FFD Box deformation in a specific direction? I mean, I want to allow the FFD Box to move in the -(negative)Z direction but not in the +(positive)Z direction. Any help will be appreciated. Thanks

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July 25, 2022, 21:00		#2
wallym Senior Member Wally Maier Join Date: Apr 2019 Posts: 123 Rep Power: 7	Hi Umuteng, Yes. I always suggest manually creating the DEFINITION_DV field. When you do, you can specify exactly the grid deformation you want to perform -> heres part of an example from SU2's tutorials suite: DEFINITION_DV= ( 11, 1.0 \| UPPER_SIDE, LOWER_SIDE, TIP \| WING, 0, 1, 0, 0.0, 0.0, 1.0 ); This FFD design variable with the FFD coordinates of (0,1,0) will only deform in the +Z directions (0.0,0.0,1.0) as defined by the last three arguments. If you want your variables to be constrained to -Z your arguments would like: DEFINITION_DV= ( 11, 1.0 \| UPPER_SIDE, LOWER_SIDE, TIP \| WING, 0, 1, 0, 0.0, 0.0, -1.0 ); Best, Wally