Originally Posted by
Cubdriver
The term parasite is a catch-all term for many types of drag, and it only matters that you distinguish between them. A few sources will lump form drag with parasite drag, which it probably should be grouped with for simplicity, while others make it a separate item because it bears more resemblance to induced drag.
Can you show how it resembles induced drag? I just spent the last hour on google and in my aerodynamics books and cannot find a source that doesn't link form/pressure drag to parasite drag. I even ran through some calculations done on the MD80 by MIT students who did not separate form drag from parasite/induced. All the sources I find show form drag is related to speed and a portion of parasite drag, not related to lift or induced drag.
I also looked for an individual formula for form and pressure drag (I realize they are the same but searched for each individually for thoroughness), coming up empty.
How does any of this disprove the use of ones hand out a window to demonstrate induced drags relationship to AOA? Assuming no drastic changes in speed are experienced during the experiment.