Fin Stabilization: Calculations, Reynolds Equation, Surface Area Effects

[Shawnzyoo]

I am trying to work through the stability forces on rocket fins
and understand how you need laminar flow for greater stabilization
but i am not sure how to accurately calculate some of these
I was told that the Reynolds Equation holds true, but uses a different cross sectional area
what cross sectional area should be used?
is it the leading edge?
also how dose changing surface area effect the equation...for example over a nose cone (small diameter to larger diameter)
thanks for any info

 

[Astronuc]

Here is a nice discussion on turbulence - http://en.wikipedia.org/wiki/Turbulence

The objective in laminar flow is to maintain more or less constant pressure in a flow field across an airfoil, otherwise the pressure various and therefore momentum would fluctuate wildly disrupting control. Significant variations in pressure differential across a control surface would cause variations in net forces normal to the direction of travel, i.e. instabilities, which can grow in magnitude in very short periods.

This is pretty cool - supersonic laminar flow - http://www.nasa.gov/centers/dryden/history/pastprojects/F16XL2/