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Unsteady shape optimization, Adjoint timestep restriction

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Old   July 31, 2019, 12:02
Default Unsteady shape optimization, Adjoint timestep restriction
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Selcuk Dilki
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Hello everyone,

I am currently trying to optimize a pulsating flow through a U-bend.

I have an unsteady flow simulation and have some transient behaviour in my first time steps. The CFD simulation works fine after one cycle and converges properly.

My problem is the Adjoint calculation for the shape optimization.
As soon as the adjoint solver reaches the first time steps it diverges, due to the transient behaviour of the flow in those timesteps.

I would like to only do the Adjoint calculation for the converged cycle.
Can I restrict the adjoint solver to do only a certain number of iterations along the CFD solutions, namely the converged ones counting from the back?


Thanks in advance for your help
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Old   December 12, 2019, 12:46
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Anna Bauer
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Hi,



did you find a solution for your problem? This would be very interesting for me.


Thanks in advance
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Old   December 13, 2019, 03:28
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Tim Albring
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Yes you can do that by setting TIME_ITER for the adjoint run appropriately. The adjoint solver starts at the direct time iteration set with UNST_ADJOINT_ITER and runs until ijt reaches the number time steps set with TIME_ITER (which are counted from the back in terms of direct time steps).
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