Adjoint CFD

[Mr. Kim Moo Sung 0]

hi 

 

i`m studying Caeses. 

 

i saw the Blog for Adjoint CFD. and i followed. i`m using Simerics for CFD and Ensight.

 

so i run Simerics and read result for Ensight format... and then i don`t know what is next...

 

how to work optimization with sensitivity...?

 

sensitivity is included in Design variant? and how..?

 

it doesn`t matter which Optimization algorism?

 

 

thanks

Adjoint_test.fdbc

[Mr. Carsten Fuetterer 9]

Dear Kim Moo Sung,

 

before you calculate the parametric sensitivities in CAESES, you need the surface sensitivities from a adjoint calculation, which comes from the CFD code. Does Simerics has an adjoint solver?

 

best regards

Carsten

[Mr. Kim Moo Sung 0]

hi 

 

thanks.  i understand. i know Simerics is not...

 

i have one more question.

 

Principle of Adjoint is calculating sensitivities in each cell, and the sensitivity shows the direction and size in a surface. and is parametric sensitivities and surface sensitivities different?

 

thanks

[Mr. Carsten Fuetterer 9]

Hi,

 

the surface sensitivity gives you a scalar field, which describes the amount you have to push or pull the surface cell inwards or outwards to lower the objective function.

 

The design velocities in CAESES gives you the information how one design variable changes the shape normal to the surface.

 

In CAESES you then combine the surface sensitivity with the design velocities, and you will get the parametric sensitivities of each design variable, which describes the gradient of objective function change to design variable change. This means you know then how much you have to change one design variable to change the objective function. You also know the influence of each design variable on the objective function.

 

best regards

 

Carsten

[Mr. Kim Moo Sung 0]

Thanks.

 

I appreciate your help. It really helped me to understand.