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-   -   ANSA adjoint sensitivity, shape morphing (https://www.cfd-online.com/Forums/ansa/219742-ansa-adjoint-sensitivity-shape-morphing.html)

Astan August 7, 2019 09:31

ANSA adjoint sensitivity, shape morphing
 
Hi guys, i am new in the use of ANSA.
I have looked on the internet but i haven't found any help to my problem so i decided to write here.

I need to use the morphing function of ANSA, i would like to ask you for an information.

I have performed my RANS and Adjoint simulations with openfoam, and the mesh has been done with SnappyHexMesh.

I know that ANSA needs the sensitivity log from openfoam, but also the mesh in order to associate each entry of the sensitivity log with the respective node in the mesh.

How can i load the mesh performed with openfoam into ansa?

Or, if this is not the correct way to procede, how can i load my stl / step model in order to perform the sensitivity morphing?

Thanks you in advance for any answer i really appreciate any suggestion.

Astan

Mahmoud_aboukhedr August 13, 2019 05:08

Hello,

You can simply follow the tutorial called:
SHAPE SENSITIVITY MORPHING
Which can be found under Help > Documentation index > Tutorials > CFD

Please let me know if you have problems after examing the Tutorial.

Best,

Astan August 13, 2019 08:57

Hi Mahmoud_aboukhedr, first of all thanks you very much for your suggestion and kindness it helped me a lot!

I would like to kindly ask you for few informations.

After that the senstivity has been uploaded into ansa, there is the possibility to smooth the sensitivity, i mean Openfoam > results > new (load the sensitivity log) and then " smooth"

I know that the adjoint output is noisy and it is required a filter operation.

I would like to know more precisely what the "smooth" and "iteration" options do, is it worth to leave the default values or reduce the value?

The second question is about the deformation map (i refer to the very end of the tutorial you kindly suggest me) just before performing the morphing the user has to specify which displacement to use.

In the voice "maximum displacement" is the displacement expressed in millimeters (i.e. 1 = 1mm, 10 = 10 mm and so on)?
And always, in that windows, what does the "range" setup is about?

The last question is about the generation of the .stl file.
I have done file --> output ---> stl, so i save the .stl of the morphed surface.

Is there a more proper way to create an .stl of the morphed surface, i have read the word "stl" in the mesh tab, but i'm struggling with it because i don't understand how to make it work ( once the my body has been morphed, it consists of a grid .ansa format, i would like to generate an .stl file from that grid in order to mesh it with openfoam ).

I'm sorry if the questions are trivial, i would like to have a more precise idea to be more sure about what i'm configuring.

Thank you very much for the time spent to read my post, any suggestions are very accepted.

Astan

Mahmoud_aboukhedr August 19, 2019 12:03

Hello again,

Apologies for the late response,
Glad to hear about your progress
So please find some short answers to your questions:

1- I would like to know more precisely what the "smooth" and "iteration" options do, is it worth to leave the default values or reduce the value?
The Smooth function will spread the results across the given mesh based on the mesh density, by increasing or decreasing the number of iterations the smoothing strength will change. Based on your results (how god or bad are they) you may need to play a bit with iteration rounds. In other words, if the results contain lots of noise, one needs to increase the number of iterations to get a smoother transition between the values.
So, based on my previous answer, you may need to increase or decrease the values based on your results and your mesh as well.


2- In the voice "maximum displacement" is the displacement expressed in millimeters (i.e. 1 = 1mm, 10 = 10 mm and so on)? And always, in that windows, what does the "range" setup is about?
The range represents the vector magnitudes that will be kept for morphing. Using this range you can dismiss some values from being included in the morphing action.

3-The last question is about the generation of the .stl file. I have done file --> output ---> stl, so i save the .stl of the morphed surface. Is there a more proper way to create an .stl of the morphed surface.
Apologies, but it's not very clear what does it mean ( more proper way).
So to answer your question let me first clarify something. When you import the volume mesh to ansa (which contain the surface and volume mesh) and apply the morphing, both surface and volume are morphed. Which means, you do not need to remesh the volume based on the surface after morphing. So one can simply export the mesh directly to OpenFOAM which will be ready to run using (Output > OpenFOAM).
Regarding the ("stl" in the mesh tab), it has nothing with exporting stl surface, but the function work for meshing surface geometry using stl algorithm.


Hopefully, my answer is clear, apologies for the long response.

Astan August 20, 2019 19:04

Hi Mahmoud_aboukhedr, thanks you very much for your answers, i will follow your suggestion in particular regarting the morphed mesh, these answers will help me a lot.

Astan


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