4 ms·
You could be right, though the diagram is not well-labeled so it's hard to say for sure. What's the big black arrow at the left-hand side? Direction of flow? I
by interroboink 3y ago
You could be right, though the diagram is not well-labeled so it's hard to say for sure. What's the big black arrow at the left-hand side? Direction of flow?
It would be nice if the accompanying text made any mention of deflection of air downwards, but it doesn't.
I take some solace that the spotty explanations in the text (eg: a single mention of Euler's Equations without any other reference) will send a curious reader to better sources.
- elteto 3y agoI’m very certain that the curved lines are streamlines. The black arrow is labeled “Free stream velocity” meaning that, in absence of any perturbation, that is the direction that the air would freely follow. I.e. it would go in a straight line. There is a mention of flow turning as the source of lift here [0] but the page you mention is taking the more mathematical approach of defining lift as the integration of pressure over the wing area. I agree that the diagram could be better, most aerodynamics textbook diagrams could be :) [0] https://www1.grc.nasa.gov/beginners-guide-to-aeronautics/what-is-lift/ https://www1.grc.nasa.gov/beginners-guide-to-aeronautics/wha... EDIT: I just reread the page with a bit more time and I have to disagree, it’s a very good explanation of lift, although it is a bit more technical than a layman’s. I can’t see anything obviously wrong with it, except that it doesn’t mention more advanced topics (e.g. turbulence).