[JPBLourenco]

Hi everyone.

I'm trying to perform a 2D shape optimization analyses but my adjoint solution take so long time and the density residual are to high in my opinion. I don't know what I'm doing wrong for my solution does not converge and does not pass for the next iteration.

Other thing that I don't understand is the initial message that appears in the adjoint log file:
"WARNING: The adjoint solver should use a non-dimensional flow solution.
WARNING: The adjoint solver should use a non-dimensional flow solution.
WARNING: The adjoint solver should use a non-dimensional flow solution.
WARNING: The adjoint solver should use a non-dimensional flow solution.
WARNING: The adjoint solver should use a non-dimensional flow solution.
WARNING: The adjoint solver should use a non-dimensional flow solution.
WARNING: The adjoint solver should use a non-dimensional flow solution.
WARNING: The adjoint solver should use a non-dimensional flow solution.
WARNING: The adjoint solver should use a non-dimensional flow solution."

Can anyone help me?
Thanks a lot.
João Lourenço



Some parts of my adjoint log file:


------------------------ Physical Case Definition -----------------------
Continuous RANS adjoint equations with frozen (laminar and eddy) viscosity.
Mach number: 0.73.
Angle of attack (AoA): 2.8 deg, and angle of sideslip (AoS): 0 deg.
Reynolds number: 6.5e+06. Reference length 1.
No restart solution, use the values at infinity (freestream).
Read flow solution from: solution_flow.dat.
Dimensional simulation.
The reference length/area (force coefficient) is 1.
The reference length (moment computation) is 1.
Reference origin (moment computation) is (0.25, 0, 0).
Surface(s) where the force coefficients are evaluated: airfoil.
Surface(s) plotted in the output file: airfoil.
Surface(s) to be analyzed in detail: airfoil.
Surface(s) affected by the design variables: airfoil.
Input mesh file name: Rae2822_mesh_final_optimized.su2

----------------------- Design problem definition -----------------------
CD objective function.

---------------------- Space Numerical Integration ----------------------
Jameson-Schmidt-Turkel scheme for the adjoint inviscid terms.
JST viscous coefficients (1st, 2nd, & 4th): 0.15, 0, 0.008.
The method includes a grid stretching correction (p = 0.3).
Second order integration.
The reference sharp edge distance is: 0.09.
Average of gradients with correction (viscous adjoint terms).
Gradient Computation using weighted Least-Squares method.

---------------------- Time Numerical Integration -----------------------
Local time stepping (steady state simulation).
Euler implicit method for the adjoint equations.
W Multigrid Cycle, with 3 multigrid levels.
Damping factor for the residual restriction: 0.95.
Damping factor for the correction prolongation: 0.95.
No CFL adaptation.
Multigrid Level: 0 1 2 3
Courant-Friedrichs-Lewy number: 2.25
MG PreSmooth coefficients: 1 2 3 3
MG PostSmooth coefficients: 0 0 0 0
MG CorrecSmooth coefficients: 0 0 0 0

------------------------- Convergence Criteria --------------------------
Maximum number of iterations: 99999.
Reduce the adjoint density residual 6 orders of magnitude.
The minimum value for the adjoint density residual is 10^(-5).

-------------------------- Output Information ---------------------------
Writing a flow solution every 1000 iterations.
Writing the convergence history every 1 iterations.
The output file format is Paraview ASCII (.vtk).
Convergence history file name: history_adjoint.
Forces breakdown file name: forces_breakdown.dat.
Adjoint solution file name: solution_adj.dat.
Restart adjoint file name: restart_adj.dat.
Adjoint variables file name: adjoint.
Surface adjoint coefficients file name: surface_adjoint.

------------------- Config File Boundary Information --------------------
Far-field boundary marker(s): farfield.
Constant heat flux wall boundary marker(s): airfoil.

---------------------- Read Grid File Information -----------------------
Two dimensional problem.
33887 points before parallel partitioning.
Performing linear partitioning of the grid nodes.
62136 interior elements before parallel partitioning.
Calling the partitioning functions.
Building the graph adjacency structure.
Distributing elements across all ranks.
2 surface markers.
154 boundary elements in index 0 (Marker = airfoil).
556 boundary elements in index 1 (Marker = farfield).
Calling ParMETIS...
Finished partitioning using ParMETIS (1435 edge cuts).
Communicating partition data and creating halo layers.
63571 interior elements including halo cells.
58545 triangles.
5026 quadrilaterals.
35436 vertices including ghost points.
Establishing MPI communication patterns.

------------------------- Geometry Preprocessing ------------------------
Setting point connectivity.
Renumbering points (Reverse Cuthill McKee Ordering).
Recomputing point connectivity.
Setting element connectivity.
Checking the numerical grid orientation.
There has been a re-orientation of the TRIANGLE volume elements.
There has been a re-orientation of the QUADRILATERAL volume elements.
There has been a re-orientation of the LINE surface elements.
Identifying edges and vertices.
Computing centers of gravity.
Setting the control volume structure.
Area of the computational grid: 1.77e+04.
Searching for the closest normal neighbors to the surfaces.
Compute the surface curvature.
Max K: 4.69e+04. Mean K: 991. Standard deviation K: 6.73e+03.
Checking for periodicity.
Setting the multigrid structure.
MG level: 0 -> CVs: 35436. Agglomeration rate 1/1.00. CFL 2.25.
MG level: 1 -> CVs: 10380. Agglomeration rate 1/3.41. CFL 1.83.
MG level: 2 -> CVs: 3018. Agglomeration rate 1/3.44. CFL 1.48.
MG level: 3 -> CVs: 950. Agglomeration rate 1/3.18. CFL 1.24.
Computing wall distances.
Wetted area = 2.03 m.
Area projection in the x-plane = 0.123 m, y-plane = 1 m.

------------------------- Driver information --------------------------
A Fluid driver has been instantiated.

------------------------ Iteration Preprocessing ------------------------
Zone 1: adjoint Euler/Navier-Stokes/RANS flow iteration.

------------------------- Solver Preprocessing --------------------------
Viscous flow: Computing pressure using the ideal gas law
based on the free-stream temperature and a density computed
from the Reynolds number.
Force coefficients computed using free-stream values.
-- Input conditions:
Fluid Model: STANDARD_AIR
Specific gas constant: 287.058 N.m/kg.K.
Specific gas constant (non-dim): 287.058
Specific Heat Ratio: 1.4
Viscosity Model: SUTHERLAND
Ref. Laminar Viscosity: 1.716e-05 N.s/m^2.
Ref. Temperature: 273.15 K.
Sutherland Constant: 110.4 K.
Laminar Viscosity (non-dim): 1.716e-05
Ref. Temperature (non-dim): 273.15
Sutherland constant (non-dim): 110.4
Conductivity Model: CONSTANT_PRANDTL
Prandtl: 0.72
Free-stream static pressure: 38726.1 Pa.
Free-stream total pressure: 55200.5 Pa.
Free-stream temperature: 288.15 K.
Free-stream density: 0.468182 kg/m^3.
Free-stream velocity: (248.12, 12.1351) m/s. Magnitude: 248.417 m/s (482.883 KTS).
Free-stream total energy per unit mass: 237645 m^2/s^2.
Free-stream viscosity: 1.7893e-05 N.s/m^2.
-- Reference values:
Reference specific gas constant: 1 N.m/kg.K.
Reference pressure: 1 Pa.
Reference temperature: 1 K.
Reference density: 1 kg/m^3.
Reference velocity: 1 m/s.
Reference energy per unit mass: 1 m^2/s^2.
Reference viscosity: 1 N.s/m^2.
Reference conductivity: 1 W/m^2.K.
-- Resulting non-dimensional state:
Mach number (non-dim): 0.73
Reynolds number (non-dim): 6.5e+06. Re length: 1 m.
Specific gas constant (non-dim): 287.058
Free-stream temperature (non-dim): 288.15
Free-stream pressure (non-dim): 38726.1
Free-stream density (non-dim): 0.468182
Free-stream velocity (non-dim): (248.12, 12.1351). Magnitude: 248.417
Free-stream total energy per unit mass (non-dim): 237645
Free-stream viscosity (non-dim): 1.7893e-05

Initialize Jacobian structure (Navier-Stokes). MG level: 0.
Initialize Jacobian structure (SA model).
Initialize Jacobian structure (Adjoint N-S). MG level: 0.
Initialize Jacobian structure (Navier-Stokes). MG level: 1.
Initialize Jacobian structure (Adjoint N-S). MG level: 1.
Initialize Jacobian structure (Navier-Stokes). MG level: 2.
Initialize Jacobian structure (Adjoint N-S). MG level: 2.
Initialize Jacobian structure (Navier-Stokes). MG level: 3.
Initialize Jacobian structure (Adjoint N-S). MG level: 3.

----------------- Integration and Numerics Preprocessing ----------------
Integration Preprocessing.
Numerics Preprocessing.

------------------------------ Begin Solver -----------------------------
Begin direct solver to store flow data (single iteration).
Compute residuals to check the convergence of the direct problem.

--------------------------- Surface Analysis -------------------------
Surface (airfoil): Mass flow (kg/s): 0.0000, Mach: 0.0000, T(K): 0.0000, P(Pa): 0.0000, TT(K): 0.0000, PT(Pa): 0.0000, Area (m^2): 2.0320.
Surface (airfoil): Dist. coeff.: IDC 29.1%. IDC Mach 0.0%. IDR 0.3%. DC60 0.0.
-------------------------------------------------------------------------
log10[Maximum residual]: -3.3, located at point 114.
End direct solver, begin adjoint problem.

---------------------- Local Time Stepping Summary ----------------------
MG level: 0 -> Min. DT: 0.0. Max. DT: 0.0. CFL: 2.2.
MG level: 1 -> Min. DT: 0.0. Max. DT: 0.0. CFL: 1.8.
MG level: 2 -> Min. DT: 0.0. Max. DT: 0.0. CFL: 1.5.
MG level: 3 -> Min. DT: 0.0. Max. DT: 0.0. CFL: 1.2.
-------------------------------------------------------------------------

log10[Maximum residual]: -inf.
Maximum residual point 0, located at (0.0, 0.0).

Iter Time(s) Res[Psi_Rho] Res[Psi_E] Sens_Geo Sens_AoA
0 2.303091 -32.000000 -4.266420 1.1915e+04 1.3791e-02
1 1.601630 0.903375 -4.325697 1.0842e+04 1.3800e-02
2 1.372444 0.793198 -4.433682 9.9079e+03 1.3994e-02
3 1.185200 0.865608 -4.456602 9.0813e+03 1.4705e-02
4 1.085957 0.926487 -4.402353 8.3418e+03 1.5925e-02
5 1.054679 0.947386 -4.382768 7.6756e+03 1.7463e-02
6 1.027409 0.950552 -4.379962 7.0726e+03 1.9008e-02
7 0.999573 0.951544 -4.384271 6.5246e+03 2.0145e-02
8 0.982015 0.956614 -4.395498 6.0251e+03 2.0595e-02
9 0.960835 0.965306 -4.413840 5.5689e+03 2.0387e-02
10 0.949245 0.973707 -4.433800 5.1514e+03 1.9761e-02
.
.
.
.
.
13991 0.468149 1.859382 -2.971052 -2.8935e+03 -4.4557e-01
13992 0.468165 1.865266 -2.968638 -2.8936e+03 -4.4557e-01
13993 0.468184 1.859382 -2.971053 -2.8935e+03 -4.4557e-01
13994 0.468205 1.865265 -2.968639 -2.8936e+03 -4.4557e-01
13995 0.468223 1.859381 -2.971054 -2.8935e+03 -4.4557e-01
13996 0.468239 1.865265 -2.968640 -2.8936e+03 -4.4557e-01
13997 0.468254 1.859381 -2.971054 -2.8935e+03 -4.4557e-01
13998 0.468262 1.865264 -2.968640 -2.8936e+03 -4.4557e-01
13999 0.468265 1.859380 -2.971055 -2.8935e+03 -4.4557e-01

---------------------- Local Time Stepping Summary ----------------------
MG level: 0 -> Min. DT: 6.626e-11. Max. DT: 0.001347. CFL: 2.25.
MG level: 1 -> Min. DT: 5.508e-10. Max. DT: 0.002259. CFL: 1.827.
MG level: 2 -> Min. DT: 3.455e-09. Max. DT: 0.00336. CFL: 1.477.
MG level: 3 -> Min. DT: 2.139e-08. Max. DT: 0.005358. CFL: 1.243.
-------------------------------------------------------------------------

log10[Maximum residual]: 3.848.
Maximum residual point 421, located at (1, -0.0001579).
There are 6 non-physical points in the solution.

Iter Time(s) Res[Psi_Rho] Res[Psi_E] Sens_Geo Sens_AoA
14000 0.468272 1.865264 -2.968641 -2.8936e+03 -4.4557e-01

-------------------------- File Output Summary --------------------------
Writing Surface Analysis file.
Writing comma-separated values (CSV) surface files.
Merging coordinates in the Master node.
Merging solution in the Master node.
Writing SU2 native restart file.
-------------------------------------------------------------------------

14001 0.468313 1.859379 -2.971056 -2.8935e+03 -4.4557e-01
14002 0.468315 1.865263 -2.968641 -2.8936e+03 -4.4557e-01
14003 0.468318 1.859379 -2.971056 -2.8935e+03 -4.4557e-01
14004 0.468333 1.865263 -2.968642 -2.8936e+03 -4.4557e-01
14005 0.468347 1.859378 -2.971057 -2.8935e+03 -4.4557e-01
14006 0.468351 1.865262 -2.968643 -2.8936e+03 -4.4557e-01
14007 0.468357 1.859378 -2.971057 -2.8935e+03 -4.4557e-01
14008 0.468365 1.865261 -2.968643 -2.8936e+03 -4.4557e-01
14009 0.468380 1.859377 -2.971058 -2.8935e+03 -4.4557e-01
14010 0.468393 1.865261 -2.968644 -2.8936e+03 -4.4557e-01
14011 0.468399 1.859377 -2.971059 -2.8935e+03 -4.4557e-01
14012 0.468405 1.865260 -2.968645 -2.8936e+03 -4.4557e-01
14013 0.468413 1.859376 -2.971059 -2.8935e+03 -4.4557e-01
14014 0.468419 1.865260 -2.968645 -2.8936e+03 -4.4557e-01
14015 0.468421 1.859375 -2.971060 -2.8935e+03 -4.4558e-01
14016 0.468430 1.865259 -2.968646 -2.8936e+03 -4.4557e-01
14017 0.468432 1.859375 -2.971061 -2.8935e+03 -4.4558e-01
14018 0.468436 1.865259 -2.968646 -2.8936e+03 -4.4557e-01
14019 0.468444 1.859374 -2.971061 -2.8935e+03 -4.4558e-01
14020 0.468454 1.865258 -2.968647 -2.8936e+03 -4.4558e-01
14021 0.468461 1.859374 -2.971062 -2.8935e+03 -4.4558e-01
14022 0.468466 1.865258 -2.968648 -2.8936e+03 -4.4558e-01
14023 0.468470 1.859373 -2.971062 -2.8935e+03 -4.4558e-01
14024 0.468481 1.865257 -2.968648 -2.8936e+03 -4.4558e-01
14025 0.468493 1.859373 -2.971063 -2.8935e+03 -4.4558e-01
14026 0.468498 1.865256 -2.968649 -2.8936e+03 -4.4558e-01
14027 0.468502 1.859372 -2.971064 -2.8935e+03 -4.4558e-01