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SU2 Shape optimization questions

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Old   March 10, 2015, 06:09
Default SU2 Shape optimization questions
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Adrien
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Hi everyone,

I am currently working on SU2 in order to optimize the shape of an airfoil for a low-reynolds application. I have several questions regarding the setting of some variables and about the process of optimization.

My case is to maximize the lift to drag ratio, while maintaing the lift coefficient above 1 and the thickness above 0.139.
My config file is based on the test cases provided, except I changed the scale in order to have a objective function ~1e-5 and gradients norm ~1e-2. Is that scaling consistent for the optimizer?

I also noticed that, at some point, SU2 was deforming the shape too much (the airfoil was no longer an airfoil) causing the solver to diverge. I changed BOUND_DV and DV_VALUE to 0.005. Is that the proper way to do it? I am not sure of what the DV_VALUE parameter is doing...

I also have a question on the optimization procedure. From what I understood about the continous adjoint gradient method, the algorithm is basically:

1) solve the direct problem
2) solve the adjoint problem
3) compute the gradient
4) deform the shape according to the largest gradient and return to 1)

In my case, I found that SU2 was performing these steps on the first iteration but then, for the following iterations it was only solving the direct problem, not the adjoint one. After a certain amount of iterations, it will evaluate the adjoint problem again.
So my question is: why SU2 is not solving the adjoint problem and computing the gradient at each iteration?

I attached my log file and my history_project.dat.

As you can see, the efficiency is not really maximized. Is there something wrong with my settings?

Thank you in advance,

Adrien
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File Type: txt history_project.txt (25.4 KB, 21 views)
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Old   April 21, 2015, 11:44
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Daquan He
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SU2 firstly calculate a gradient through adjoint method, then a line search is carried out in that direction. After several trials, an optimized point is found in this direction, and during the line search the gradient is not calculated. The iterations between 2 gradient evaluation steps are line search steps. This is my understanding of the algorithm.
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Old   April 21, 2015, 13:57
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Adrien
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Hi,

Thanks for you answer. This seems to be working this way indeed.
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Old   January 27, 2016, 01:51
Default i need su 2 shape optimizatin cfg file for su2 4.0.0
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balaji
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i want do shape optimization by using python program please help how do and if i want to install python software
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Old   January 27, 2016, 05:02
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Tim Albring
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Hi bala732,

please consult the wiki first: https://github.com/su2code/SU2/wiki

If there are more specific questions we can help you with that.
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Old   January 27, 2016, 05:19
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balaji
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thank u i found by python
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Old   January 27, 2016, 05:25
Default error in python coding
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balaji
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this error are coming for my python how to rectify it my old_pr_ke4.jpgthis my codes and my error isold_pr_ke5.jpg
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