Hi Bill,
That’s a Bristol design. It was a design sample for another system and I don’t
have any data on it.
Anthony J. Cesaroni
President/CEO
Cesaroni Technology/Cesaroni Aerospace
http://www.cesaronitech.com/
(941) 360-3100 x1004 Sarasota
(905) 887-2370 x222 Toronto
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From: arocket-bounce@xxxxxxxxxxxxx <arocket-bounce@xxxxxxxxxxxxx> On Behalf Of
William Claybaugh
Sent: Thursday, July 15, 2021 3:07 PM
To: arocket@xxxxxxxxxxxxx
Subject: [AR] Re: Spin Thrust
Anthony:
Genius. I’m particularly impressed by the spirals.
Is that pre-firing?
Can you say what spin rate was induced and how that coupled to the vehicle mass
properties? Happy to go off-line if needed; I believe we still have an NDA.
I get it that inducing swirl in the entrance is somewhat easier than dealing
with the nozzle exhaust flow but I’ve engineered myself into doing this at the
nozzle exit, this time. Any thoughts?
Can you make me one?
Bill
On Thu, Jul 15, 2021 at 12:09 PM Anthony Cesaroni
<anthony@xxxxxxxxxxx<mailto:anthony@xxxxxxxxxxx>> wrote:
CRV-7 nozzle FYI.
[A picture containing indoor, metalware, engine, gear Description
automatically generated]
Anthony J. Cesaroni
President/CEO
Cesaroni Technology/Cesaroni Aerospace
http://www.cesaronitech.com/
(941) 360-3100 x1004 Sarasota
(905) 887-2370 x222 Toronto
From: arocket-bounce@xxxxxxxxxxxxx<mailto:arocket-bounce@xxxxxxxxxxxxx>
<arocket-bounce@xxxxxxxxxxxxx<mailto:arocket-bounce@xxxxxxxxxxxxx>> On Behalf
Of William Claybaugh
Sent: Wednesday, July 14, 2021 8:53 PM
To: arocket@xxxxxxxxxxxxx<mailto:arocket@xxxxxxxxxxxxx>
Subject: [AR] Re: Spin Thrust
Carl:
The fins are “hexagonal” cross-section and taper from root to tip; the leading
& trailing edges also taper to a 0.025” radius edge. For the near term, they
are what they are….
But to directly answer your question, the force generated is a function of
surface; thus canted fins are much preferred to an offset leading (or trailing)
edge. Similar comments would apply wrt fin tabs….
Bill
On Wed, Jul 14, 2021 at 6:38 PM Carl Tedesco
<ctedesco@xxxxxxxxxxxxxx<mailto:ctedesco@xxxxxxxxxxxxxx>> wrote:
Bill,
Although your question is for information on exhaust vanes to induce roll, I
have to ask…
Assuming the typical aligned fins with through-wall mounting, and assuming they
are made from flat metal plates, why not just have an asymmetrical leading edge
chamfer on each fin to induce spin? I feel like I saw that on a big solid
rocket at the RRS about 20 years ago (the Garboden booster?).
--- Carl
From: arocket-bounce@xxxxxxxxxxxxx<mailto:arocket-bounce@xxxxxxxxxxxxx>
<arocket-bounce@xxxxxxxxxxxxx<mailto:arocket-bounce@xxxxxxxxxxxxx>> On Behalf
Of William Claybaugh
Sent: Wednesday, July 14, 2021 2:28 PM
To: arocket@xxxxxxxxxxxxx<mailto:arocket@xxxxxxxxxxxxx>
Subject: [AR] Spin Thrust
I'm thinking that I would like (nee: the FAA will likely appreciate) it if my
nine inch rocket spun up to around 9 rpm. The canonical approach is of course
to offset the fins, which in this case would require about 0.040" total offset
(0.020' top and bottom, in opposite directions). Getting an accurate .020"
offset appears to be problematic given the through-the-wall fin attachment
schema used on this rocket.
Which leads me to ask about spinning the rocket via canted fins set into the
exhaust gas. Obviously, these induce losses in performance, which suggests--to
me--that minimizing them is a good idea: four come to mind as the likely
minimum practical set. Among the things I am not clear on is how much cant I
would need on these four fins and of what material (graphite?) they would need
to be made to survive the 8.3 seconds of high temperature and velocity sand
blast.
Anyone know of a reference that ties exhaust fin cant angle to vehicle spin
rate? Or of what materials such fins might be made and how attached?
Bill