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Geometric Constraints and Gradients for Constrained Wing Optimization

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Old   January 24, 2014, 15:38
Default Geometric Constraints and Gradients for Constrained Wing Optimization
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Tommy Chen
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Hi Stanford Guys

in the Tutorial 8
http://adl-public.stanford.edu/docs/...f+a+Fixed+Wing

There are thickness constraints along 5 sections of the wing, which are
MAX_THICKNESS_SEC1-5
However , I do not understand how do the solver determine the locations along the span direction of the wing for these 5 Thickness constraints.

Besides, I am reading the python scripts , I found that in the SU2/eval/gradients.py
the part of codes for
Mesh updating , mesh decomposition and deformation, and geometry solution
has been commented. like below:

##################################
# in SU2/eval/gradients.py

# ----------------------------------------------------
# Update Mesh (check with Trent)
# ----------------------------------------------------

# does decomposition and deformation
# info = update_mesh(config,state)


# ----------------------------------------------------
# Geometry Solution
# ----------------------------------------------------

##################################

Then how does SU2 calculate the geometric gradients, and how to achieve the geometry constraints like thickness??
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Old   January 28, 2014, 16:39
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Trent Lukaczyk
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haha nice. yup that line is supposed to be commented. i'm not sure how the code determines the span locations (maybe it's evenly spacing them along the monitors markers in the y direction?). It calculates surface sensitivities to geometry by finite difference inside SU2_GDC, using the same routines as SU2_MDC
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Old   January 28, 2014, 22:06
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Quote:
Originally Posted by rktchip View Post
haha nice. yup that line is supposed to be commented. i'm not sure how the code determines the span locations (maybe it's evenly spacing them along the monitors markers in the y direction?). It calculates surface sensitivities to geometry by finite difference inside SU2_GDC, using the same routines as SU2_MDC
Hi Trent

Thank you for your reply.

I have another question, I found out that the mesh deformation code has to be coupled with the design variables, suppose that I already have a deformed surface mesh, and I want to use SU2_MDC to get the deformed volume SU2 mesh with either spring or FEA method. Is that possible ? If it is, how can I do that?

Thanks
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Old   January 29, 2014, 03:09
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Trent Lukaczyk
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if i understand your question right, SU2_MDC deforms both the surface and the volume mesh. The *.su2 file that comes out is the deformed volume mesh (including the markers that identify the surface)
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Old   January 29, 2014, 09:20
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Quote:
Originally Posted by rktchip View Post
if i understand your question right, SU2_MDC deforms both the surface and the volume mesh. The *.su2 file that comes out is the deformed volume mesh (including the markers that identify the surface)
Right, that also means the users can only chose to parameterize the surface mesh by the existing methods within SU2. So , in SU2_MDC.cpp

################################################## ###
if (rank == MASTER_NODE) cout << endl << "------------------------- Surface grid deformation ----------------------" << endl;

/*--- Definition and initialization of the surface deformation class ---*/

surface_movement = new CSurfaceMovement();
surface_movement->CopyBoundary(geometry[ZONE_0], config[ZONE_0]);

/*--- Surface grid deformation ---*/

if (rank == MASTER_NODE) cout << "Performing the deformation of the surface grid." << endl;
surface_movement->SetSurface_Deformation(geometry[ZONE_0], config[ZONE_0]);

#ifndef NO_MPI
/*--- MPI syncronization point ---*/
#ifdef WINDOWS
MPI_Barrier(MPI_COMM_WORLD);
#else
MPI::COMM_WORLD.Barrier();
#endif
#endif
################################################## ##################

If I modify this line :
surface_movement->SetSurface_Deformation(geometry[ZONE_0], config[ZONE_0]);

can I make the SU2_MDC read some existing deformed surface mesh from file instead of deforming it within SU2_MDC?

Thanks Trent
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Old   January 29, 2014, 12:00
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Quote:
Originally Posted by rktchip View Post
if i understand your question right, SU2_MDC deforms both the surface and the volume mesh. The *.su2 file that comes out is the deformed volume mesh (including the markers that identify the surface)
Never mind

I found that this could be achieved by defining the DV_KIND=surface_file and passing the MOTION_FILENAME of the deformed surface file to it

cheers
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