Using opti.variable inside asb.Aerobuildup

[karmix96]

I want to create an optimization environment, where i define a flying wing in 10 total segments. Every segment, corresponds to an asb.XSec and has different dihedral angle and twist angle. The goal is to choose the best combination of dihedral and twist angle for every segment using asb.Aerobuildup and minimizing aero["CD"].
Can i define opti.variables for all dihedral and twist angles and use them inside asb.Aerobuildup?

[peterdsharpe]

Yes, that should work! You will want to define these as opti.variable() during the geometry creation. To put in dihedral, you will need to modify the xyz_le of the asb.WingXSec objects within the wing (as the cross sections are parameterized by position, not dihedral angle).

Then, put that asb.Wing into an asb.Airplane, and you can call asb.AeroBuildup on it. From there, you can do opti.minimize() on the resulting CD, and set up your optimization problem.

---

On a more conceptual note rather than a computational one: don't forget to set reasonable other constraints (e.g., lift constraint, zero-moment, span constraint), otherwise you may accidentally create an unbounded or impractical optimization problem. Setting upper and lower bounds on the twist and dihedral can also help, as the solver will use this information to scale the optimization problem to be better-conditioned.

[karmix96]

Thank you for your fast reply, i already used it and it works. Although some functions that i have previously defined numerically in my comceptual_airplane_workflow, now need to be written symbolically.