Implement general wing geometry

[jorgepiloto]

Let me propose an interesting upgrade: imagine we want to carry out a simulation on a general wing geometry like the one shown below:

At the moment, ezaero is able to properly mesh and solve for trapezoidal lifting surfaces. This new feature would require a software refactoring, but any geometry could be generated!

I propose the following steps to achieve this new feature:

• Generate a vlm/lifting_surface.py module which holds the definition of a LiftingSurface class. This class holds all geometrical definitions for a small trapezoidal section. It contains a plot() method for showing the current geometry without having to run a simulation. Also, it includes a new r_offset when building the object, which is the position vector of the leading edge of the root. This will enable to move the part along the global model geometry.

• Instead of a single wing, a list of LiftingSurfaces modeling the global geometry is passed to the Simulation instance. Influence coefficient matrices are stacked and a global solution is finally achieved. Testing cases can be implemented from this online solver.

Let me now what you think about this new feature when possible, @partmor :+1:

[jorgepiloto]

With previous presented approach, it is easy to model complex shapes:

wing_root = LiftingSurface(
    r_offset = np.array([0,0,0]),
    root_chord=1.5,
    tip_chord=0.5,
    planform_wingspan=4,
    sweep_angle=30 * np.pi / 180,
    dihedral_angle=15 * np.pi / 180,
)

wing_tip = LiftingSurface(
    r_offset = wing_root.LE_tip,
    root_chord=0.5,
    tip_chord=0.1,
    planform_wingspan=2,
    sweep_angle=75 * np.pi / 180,
    dihedral_angle=45 * np.pi / 180,
)

for part in [wing_root, wing_tip]:
    fig = part.plot(fig)

fig.show()

Which outputs the following:

[partmor]

Hi @jorgepiloto!

I LOVE this proposal. You just aced one of the "that would be nice..." things I've had in my head for a while!

Please go ahead and open a PR whenever you like, and we can discuss together the needed refactors directly on the code ;)

Thank you again

[jorgepiloto]

This is looking good in my local machine. Still need to go through complete matrix solution but meshing and wake (which adapts to Uinf vector) are properly generated:

[jorgepiloto]

In previous image, wake offset was reduced for a better visualization.

[partmor]

Great stuff!! Looking forward to seeing the final result! ^^

[partmor]

Hi @jorgepiloto just checking in; all good? if you need any help please reach out :)