[atelcikti1]

Hi community,


I am working on axisymmetric nozzle diverging part optimization in SU2 using discrete adjoint module. I create a FFD box of size 10x10 with polynomial order 2. Try both SLSQP and BFGS optimization algorithms. I am using both ROE and AUSM for flow and adjoint discretization. Both adjoint and flow solutions converges well expect adjoint-y velocity. But this does not create any problem. I have another issue about opt.



My opt. options simply;


% Factor to reduce the norm of the gradient (affects the objective function and gradient in the python scripts)
% In general, a norm of the gradient ~1E-6 is desired.
OPT_GRADIENT_FACTOR= 1E-6

% Factor to relax or accelerate the optimizer convergence (affects the line search in SU2_DEF)
OPT_RELAX_FACTOR= 1E+0

% Maximum number of optimizer iterations
OPT_ITERATIONS= 500

% Requested accuracy
OPT_ACCURACY= 1E-12


% Upper bound for each design variable
OPT_BOUND_UPPER= 0.015

% Lower bound for each design variable
OPT_BOUND_LOWER= -0.015




My optimization objective is momentum force at pressure_outlet which is as expected value in flow solution. However, in first opt. iteration throat is deflected in high value and other diverging part remains same. And optimizer decreases the design values in to highly smaller numbers such that 10^-13. Then I cannot see any increment in thrust.


What do i do worng? By the way, I cannot share .cfg and grid files since my advisor strictly reject to share on forum (I have no idea why he thinks like that )