The cliff a rough ball reaches sooner
The drag coefficient of a sphere against Reynolds number, on log axes. The smooth curve is Morrison's correlation, which is a fit to measurements and is drawn in the colour this site reserves for a borrowed claim. The other is the same curve shifted along the Reynolds axis by a factor of 6 — a stated model of what roughness does, which is to trip the boundary layer early, and not a measurement of any real ball.
5 essays call
sphere-drag. The drawing above is what it returns with no arguments at all; every
call below passes it something, because a placement that passes nothing draws whichever member
of the family the generator happens to default to rather than the one its essay argues about.
It is also the blast radius. Changing sphere-drag changes every figure listed here
at once, and on this site it may change what they assert as well as what they show —
which is what has to be rebuilt and looked at before the change is believed.
Where it is called
What each of these essays asks for instead of the defaults is on the regime index, which reads the parameters back out of the finished figures rather than out of the placements.
- The drag that falls as it speeds up Fluids at work
- A ball that swings without spinning Fluids at work
- How small is small enough Regimes and numbers
- The drop that is not a tear Regimes and numbers
- The ball that never forgets its spin Fluids at work