[soura579]

Hello everyone,

I am quite new to the SU2 software and I have been trying to perform an FFD shape deformation on an aircraft rudder. I have learnt that the procedure to perform the deformation is: to create an FFD box on the mesh file using DV_KIND = FFD_SETTING and to create an FFD box using the FFD_DEFINITION; then run the SU2_DEF command to obtain the mesh file with the FFD information in it; next use another configuration file and update DV_KIND = FFD_ROTATION (I have also tried FFD_TWIST_ANGLE and FFD_CONTROL_SURFACE) and run the SU2_DEF command once again for the new mesh.

I view the mesh in paraview but there is no deformation observed. There is no change in values in the ffd_boxes.dat file either.

When I run the first SU2_DEF command to add the ffd information in the mesh file, I get a series of the following message:
Please check this point: (0.690985 -0.0908935 0.51206) <-> (34.1992 0.0276544 4.293).

and the terminal says the ffd information is added to the SU2 file.

When I run the second SU2_DEF command, the terminal says: There are 5 elements with negative volume.

Am I missing something here? I am not able to figure out where I am going wrong.

I have attached screenshots of the grid deformation and free form deformation parameters of my configuration file. Please let me know if you need additional documents in order to understand my problem better.

Your help is greatly appreciated

PS: I am using SU2 version 4.0

With regards,
Sourabh

[talbring]

Hi Sourabh,

is the FFD Box cutting the surface ? If so, increase the FFD_DEGREE, otherwise all of the planes are held fixed.

Tim

[soura579]

Hello Tim,

Thanks for your reply. Increasing the FFD degree does not seem to work. I am still getting the message: "There are 1597 elements with negative volume". When viewing the deformed mesh in Paraview, there are some weird deformed patches. I have attached the rudder image of the deformed mesh. I have also attached the FFD setting configuration file (rudder_setting.txt). I would appreciate it if you could take a glance at the files and see where I am going wrong.

Thank you.

With regards,
Sourabh