[Bortolazzi]

Hi developers,

I was trying to understand how the objective function sensitivities w.r.t. the design variables are computed, but I could not understand the meaning of the variable called Sensitivity.

If I well understood, it's a scalar product between the flow solution and the adjoint solution at a given node, which is performed by solution_adjoint_mean.cpp and stored in AuxVar.
Afterwards, this value is multiplied by the sensitivity of the node's displacement w.r.t. a given design variable in order to compose the sensitivity of the objective function w.r.t. this design variable.

Could you explain the meaning of the variable Sensitivity, as well as the mathematical formulation used to compute the final sensitivities of the objective function w.r.t. the design variables?

Thanks in advance.

Best regards,

Andre

[fpalacios]

Dear Andre,

The implemented formulation is described in several articles like:
http://adl.stanford.edu/papers/AIAA_..._March2012.pdf
http://adl.stanford.edu/papers/AIAA-2013-0632.pdf
or
http://adl.stanford.edu/papers/AIAA-2013-0287.pdf

The variable (surface) sensitivity is the derivative of the objective function with respect to perturbations of the geometry (in the normal direction).

Best,
Francisco

Originally Posted by Bortolazzi

Hi developers,

I was trying to understand how the objective function sensitivities w.r.t. the design variables are computed, but I could not understand the meaning of the variable called Sensitivity.

If I well understood, it's a scalar product between the flow solution and the adjoint solution at a given node, which is performed by solution_adjoint_mean.cpp and stored in AuxVar.
Afterwards, this value is multiplied by the sensitivity of the node's displacement w.r.t. a given design variable in order to compose the sensitivity of the objective function w.r.t. this design variable.

Could you explain the meaning of the variable Sensitivity, as well as the mathematical formulation used to compute the final sensitivities of the objective function w.r.t. the design variables?

Thanks in advance.

Best regards,

Andre