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The design of airfoils was predicated by the study of flow around a cylinder.

Experimental evidence shows that you can calculate the flow field of an airfoil if it satisfies certain conditions, the so called Kutta condition. IE having a smooth leading edge and a sharp trailing edge.

This is because you can take a cylinder and apply a mathematical transformation, called the Kutta-Jukowski theorem, and get the estimated flow around an airfoil that satisfies the so called Kutta condition. Perhaps it's a bit of a cosmic joke that the trailing edge must be sharp and Kutta da wind in order for the condition to hold.

Anyway, what does this tell us in plain English anyone can understand? It shows us that the vortices that form at the wing tips of an airfoil are merely part of a larger 3 dimensional vortex. This vortex envelops the entire airfoil.

Experiments hint that this is actually true, for instance if you cut a vortex ring with an airfoil just right, you see it creates upwash at the leading edge of the airfoil, hinting at global circulation, as if it were a cylinder.

https://youtu.be/NF4cf8XFV8k?t=36

More rambling incoming.

The design of airfoils was predicated by the study of flow around a cylinder. Experimental evidence shows that you can calculate the flow field of an airfoil if it satisfies certain conditions, the so called Kutta condition. IE having a smooth leading edge and a sharp trailing edge. This is because you can take a cylinder and apply a mathematical transformation, called the Kutta-Jukowski theorem, and get the estimated flow around an airfoil that satisfies the so called Kutta condition. Perhaps it's a bit of a cosmic joke that the trailing edge must be sharp and Kutta da wind in order for the condition to hold. Anyway, what does this tell us in plain English anyone can understand? It shows us that the vortices that form at the wing tips of an airfoil are merely part of a larger 3 dimensional vortex. This vortex envelops the entire airfoil. Experiments hint that this is actually true, for instance if you cut a vortex ring with an airfoil just right, you see it creates upwash at the leading edge of the airfoil, hinting at global circulation, as if it were a cylinder. https://youtu.be/NF4cf8XFV8k?t=36 More rambling incoming.

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[–] • 1 pt

O e of the least recognized phenomenon associated with airflow is the electrostatic charges and the forces that can build up which under the right circumstances can control airflow and provide additional or substraction of lift.

This is dependent upon conductivity of the airfoil, dryness of the air etc.

[–] • 0 pt

That I never even thought of, thanks man. It makes sense too just the thought of dust being swirled around by a vortex makes me think of electric charges. Have you seen on some hurricanes, there are concentric rings just like an electric discharge.