Quote:
Originally Posted by Cd
How does downwash appear different from the surrounding tufts ?
Do tufts in a downwash remain steady, or do they flutter in any way different from areas of the car that are not in downwash ?
What clues are there that certain tufts are in downwash ?
|
1) 'Appearance' is the main talking point.
2) You'd be hard-pressed to make the distinction without smoke.
3) A fatal trap!
--------------------------------------------------------------------------------------
Here's a reverse construction of the phenomena:
A) The tufts are held in place within a downwash.
B) The downwash is induced by attached, longitudinal vortices.
C) The attached longitudinal vortices are symptomatic of flow separation.
D) The flow separation is symptomatic of exceeding the threshold magnitude of adverse pressure gradient, responsible for triggering separation of the aft-body flow.
E) The trigger is provided by too radical a constriction of body cross-section and the accompanying pressure spike, intolerable to the TBL.
F) The body shape itself is the 'trigger.'