ORIGINAL: KenLitko
You just described a 2D wing. Downwash is created, but not at the expense of lift (in other words, it is not induced). Downwash in this case is equalled by upwash. Induced drag is a differential between these two... and none exists in a 2D wing.
No, a 2D wing does not generate downwash, which is why it produces no induced drag. In no sense is induced drag a differential between upwash and downwash. I have no idea what you are saying here.
If you can articulate how spanwise flow is necessary for downwash, please help me here. This was your claim before.
This differential is what I am talking about... but we we're talking about induced drag, so I wasn't getting into the 2D stuff that I mentioned above because it doesn't contribute to 3D drag.
Again, I have no idea what you are trying to say. This does not explain how spanwise flow is required for induced drag.
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