[AR] Re: Dynamic stability in supersonic rockets
- From: Henry Spencer <hspencer@xxxxxxxxxxxxx>
- To: Arocket List <arocket@xxxxxxxxxxxxx>
- Date: Wed, 17 Nov 2021 18:54:12 -0500 (EST)
On Wed, 17 Nov 2021, John Stoffel wrote:
crogers168> ...The jet damping contribution to the dynamic stability
allowed a statically unstable rocket to successfully fly...
This is really interesting info, so now the question I have is how do
you handle this properly so that you don't go end over end? Or have
the rocket break due to aerodynamic loads.
It doesn't really change the situation much, except insofar as it can
mislead you about how stable your design is, because it helps the
situation until burnout. After burnout, the fins need to be big enough to
do the whole job, perhaps helped by spin stabilization. (Or else the
rocket needs elevons etc. run by an active control system.)
Does Falcon 9 or Atlas V have the same worries? Or are they just
staging so high up it's not a problem for them?
Big rockets are often aerodynamically unstable over much of their flight
envelope. They have active control systems and use thrust vectoring
during powered ascent, and they usually stage high enough that
aerodynamics are not a big consideration by that point.
Henry
Other related posts: