[Elvis_M]

Hello everyone,
I use adjointOptimisationFoam to shape-optimize a geometry consisting of several cubes. The solver was slightly modified, the apparent porosity in the Navier-Stokes equation was removed. Compiling works and simulating other geometries also worked.

My problem is that the adjoint system of equations does not converge and always diverges after a few 1000 iterations (due to large continuity error). The primal system converges.

I have attached pictures of the primal and adjoint residuals.

I tried the following:
- Refine mesh
- Vary relaxation factors
- Increase cylinder diameter

I will also try do increase the cylinder length before and after the geometry.
Do you have any ideas what else I can try?

This is my fvSolution:

solvers
{
    "(p|pa)"
    {
        solver          GAMG;
        tolerance       1e-08;
        relTol          0.001;  // was 0.01	
        smoother        GaussSeidel;
    }

    "(U|Ua)"
    {
        solver          smoothSolver;
        smoother        GaussSeidel;
        nSweeps         2;
        tolerance       1e-08;
        relTol          0.01; // was 0.1
    }
}

SIMPLE
{
    nCorrectors 3;
	nNonOrthogonalCorrectors 0;
	momentumPredictor   yes;
}

relaxationFactors
{
    fields
    {
        p               0.1; // was 0.3
		pa              0.1; // was 0.2
        alpha           0.1; // was 0.1
    }
    equations
    {
        U                          0.1; // was 0.7
		Ua                         0.1; // was 0.3
    }
}

Thanks in advance,
Elvis