[bikalpa10]

Hello everyone,

I am using SU2 version 7.0.6. and trying to perform 3D optimization of delta wing Micro Air Vehicle at Re 10^5. with following settings.

Incompressible RANS model,
Turbulence Model: SA,
CFL: 20,
Euler implicit method for the flow equations.
FGMRES is used for solving the linear system.
Using a ILU(0) preconditioning.
Max number of linear iterations: 10.

Mesh quality metric
+--------------------------------------------------------------+
| Mesh Quality Metric| Minimum| Maximum|
+--------------------------------------------------------------+
| Orthogonality Angle (deg.)| 15.9908 | 89.9951|
| CV Face Area Aspect Ratio| 1.01323| 591.614|
| CV Sub-Volume Ratio| 1 | 732.846|
+--------------------------------------------------------------+

Direct simulation converged up to rms[P]= -10.4.

However, the discrete adjoint solver diverged from just 20 iterations.
I have also tried various other settings, all settings gave divergence.

• CFL= 5
• Max linear Solver Iteration = 50
• Frozen the turbulent viscosity in the discrete adjoint formulation (NO, YES)
  FROZEN_VISC_DISC= YES
• JACOBI precondition

I have attached the direct log file, adjoint log file, and adjoint history for reference