Getting old and forgetfull: flow becomes non-laminar at "x" degree.. 10? 12? 17?
 

I've heard all kinds of numbers over the years, but a while back when posting here I finally figured out what the correct answer is. (I know *it depends* on speed, humidity and elevation, but let's say... really really subsonic, like 65mph, 60% humidity and sea level)

And a ball park is fine, I'm building a rear fairing for a street car, not a fighter jet. :D

When the reynolds number exceeds 3000?

(digging through mental cobwebs)
I *think* that's what I'm talking about. :o

I remember a rule of thumb for back hatches/fairings that went something like "remember, if the angle is more than "x" degrees and the flow will separate and you'll have turbulence"

But I can't find the dall garned number for "x". :(

It might be in one of these:
https://www.gassavers.org/showthread.php?t=4527
https://www.gassavers.org/showthread.php?t=1298

From:
https://www.google.com/custom?hl=en&c...%3A6eyn0a2-udg

The answer to all questions is:
42:cool:

That's only the answer, they have finished calculations on the question. damn mice.:p

Is that your final answer?