Multiple FFD Boxes

mlooti · June 15, 2016, 08:09

Hello everybody

How can I create multiple FFD boxes on different parts of my geometry? Di I have to put two "FFD_DEFINITION=" in "FREE-FORM DEFORMATION PARAMETERS " tab ?
how do I specify DEGREE?

and
how to implement it to DEFINITION_DV? DO I have to insert more?

thanks alot

Sprotte · July 20, 2016, 05:43

Hi,

did you find an answer whether it's possible to create multiple FFD boxes with one SU2_DEF-run?

Regards, Ole

mlooti · July 25, 2016, 01:27

sorry for my late reply. Below you can find an example for a definition of two FFD boxes (in 2D):

FFD_DEFINITION = (WING, -0.659996, -0.111038, 0, -0.659996, 0.133657, 0, 0.207573, 0.133657,0, 0.207573,-0.111038,0, 0, 0, 0, 0, 0, 0, 0, 0,0, 0 ,0,0); (FLAP, 0.28366, -0.123099, 0, 0.28366,0.008809, 0, 0.67249, 0.008809, 0, 0.67249,-0.123099, 0, 0, 0, 0, 0, 0, 0, 0, 0,0, 0 ,0,0 )

FFD_CONTINUITY = 2ND_DERIVATIVE

FFD_DEGREE = (10,10, 0); (10,10, 0)

To get the correct settings for DEFINITION_DV you have to run the set_ffd_design_var.py script twice, i.e. for each box separately.

angupraveen · July 8, 2019, 05:40

So I am trying to optimize a BWB aircraft wing whose dimensions are approximately (39,42,6) in x y and z directions respectively. But I am not able to understand how to generate FFD box with this.

These dimensions are used in the tutorial and other places at FFD degree.

What am I not understanding here, Please help!

Kind regards

Angu

Marco_Vanderbijl · July 9, 2019, 11:29

I noticed that getting the FFD definition into the su2 mesh is buggy, SU2 version 5.0.0 seems to still work.

Once the FFD is correctly defined then newer SU2 version will correctly apply the (in my case) twist.

The set_ffd_design_var.py script is not used anymore, instead you run your config file with DV_KIND=FFD_SETTING to get the ffd boxes into the su2mesh, then change the config file to DV_KIND=FFD_TWIST, FFD_TWIST, FFD_TWIST (you must set DV_KIND for each box that you have, so 3 boxes in this example)

June 15, 2016, 08:09	Multiple FFD Boxes	#1
mlooti Member Tom Join Date: Oct 2015 Posts: 67 Rep Power: 10	Hello everybody How can I create multiple FFD boxes on different parts of my geometry? Di I have to put two "FFD_DEFINITION=" in "FREE-FORM DEFORMATION PARAMETERS " tab ? how do I specify DEGREE? and how to implement it to DEFINITION_DV? DO I have to insert more? thanks alot Last edited by mlooti; June 15, 2016 at 10:06.

July 25, 2016, 01:27		#3
mlooti Member Tom Join Date: Oct 2015 Posts: 67 Rep Power: 10	sorry for my late reply. Below you can find an example for a definition of two FFD boxes (in 2D): FFD_DEFINITION = (WING, -0.659996, -0.111038, 0, -0.659996, 0.133657, 0, 0.207573, 0.133657,0, 0.207573,-0.111038,0, 0, 0, 0, 0, 0, 0, 0, 0,0, 0 ,0,0); (FLAP, 0.28366, -0.123099, 0, 0.28366,0.008809, 0, 0.67249, 0.008809, 0, 0.67249,-0.123099, 0, 0, 0, 0, 0, 0, 0, 0, 0,0, 0 ,0,0 ) FFD_CONTINUITY = 2ND_DERIVATIVE FFD_DEGREE = (10,10, 0); (10,10, 0) To get the correct settings for DEFINITION_DV you have to run the set_ffd_design_var.py script twice, i.e. for each box separately. bkay, nuaa_bird, Marco_Vanderbijl and 1 others like this.

July 8, 2019, 05:40	Unable to understand how to give the FFD definition	#4
angupraveen New Member Angu Praveen Join Date: May 2019 Posts: 14 Rep Power: 6	So I am trying to optimize a BWB aircraft wing whose dimensions are approximately (39,42,6) in x y and z directions respectively. But I am not able to understand how to generate FFD box with this. These dimensions are used in the tutorial and other places at FFD degree. What am I not understanding here, Please help! Kind regards Angu

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July 20, 2016, 05:43		#2
Sprotte Member Ole Burghardt Join Date: Mar 2016 Location: Kiel, Germany Posts: 60 Rep Power: 10	Hi, did you find an answer whether it's possible to create multiple FFD boxes with one SU2_DEF-run? Regards, Ole

July 9, 2019, 11:29		#5
Marco_Vanderbijl New Member marco Join Date: May 2019 Posts: 12 Rep Power: 6	I noticed that getting the FFD definition into the su2 mesh is buggy, SU2 version 5.0.0 seems to still work. Once the FFD is correctly defined then newer SU2 version will correctly apply the (in my case) twist. The set_ffd_design_var.py script is not used anymore, instead you run your config file with DV_KIND=FFD_SETTING to get the ffd boxes into the su2mesh, then change the config file to DV_KIND=FFD_TWIST, FFD_TWIST, FFD_TWIST (you must set DV_KIND for each box that you have, so 3 boxes in this example)