Discrete vs Continuous Adjoint solution variable: Scaling/normalization issue?
 

Hello all,

Why are the Discrete adjoint solution (psiRho, for ex) values order of magnitude different from the Continuous adjoint solution values? Referring to the QuickStart tutorial, I could match exactly with the continuous adjoint solution. However, when run with MATH_PROBLEM=DISCRETE_ADJOINT option with the same config file (inv_NACA0012.cfg) the adjoint solution variables is order of magnitude different than the continuous adjoint. See attached figures. The figures also include Continuous vs Discrete surface sensitivity plot.

I actually verified the Discrete adjoint sensitivity with the Direct Derivatives, besides verifying dCd/dM from FD with Disc Adj. Is there some internal normalization for Disc Adjoint solution that is saved in adjoint restart file?
Any pointers would help.

This is something I am also experiencing. Did you find the reason for this in the end?

Z

I guess you used two different configuration files for continuous and discrete runs.

You might look at the REF_DIMENSIONALIZATION in the configuration file and make sure that the non-dimensionalization is the same between the two adjoint runs.