What exactly are upwash, downwash and propwash? My understanding is:

  • Upwash is the fluid (air) that initially flows over the wing
  • Downwash is the fluid going down the wing
  • Propwash is a byproduct of the thrust created by the propeller, and you would experience it ahead of the propeller

Is that correct?

  • $\begingroup$ See Why does the vortex created by wing affects its own angle of attack? for upwash and downwash. See SKYbrary for prop wash. $\endgroup$
    – mins
    Feb 27, 2017 at 0:13
  • $\begingroup$ I don't understand the answer. Is upwash the flow of air over the wing that rotates upward and then when it turns inboard, it is downwash? $\endgroup$
    – nyorkr23
    Feb 27, 2017 at 3:35
  • $\begingroup$ The wing turns air downward, this is the origin of lift, but air moved downward must be replaced by air coming from the underside of the wing. This exchange takes place in tip vortices. The overall upward displacement is the upwash. On the top/bottom sides of the wing, there are respectively an inward/outward flows which creates smaller "bound" vortices with corresponding upwash (ahead of the wing) and downwash (behind). More here, see this picture. $\endgroup$
    – mins
    Feb 27, 2017 at 8:06


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