Ben,
Thanks for reposting this article; it is quite informative.
I'd like to get a copy of the source material and write a time-dependent
simulation over the summer, if for no other reason than personal interest,
but it seems there is a very strong argument to be made in favor of steel
satisfying our needs.
We can look into adding a thermocouple and data logger to the subscale
prototype to check the results of the code.
Alex
On Apr 6, 2017 10:05 PM, "Ben Brockert" <wikkit@xxxxxxxxx> wrote:
One of the old Sugarshot concepts was very aggressive off the pad
(mach 4.9 under 50kft) so I ran the numbers on it from a missile
design book. I'm sure I've posted this link before, apologies for
repeating it: https://sugarshotsolidworks.wordpress.com/2013/12/22/
numeric-analysis-of-nose-cone-heating-first-steps/
The last chart and text are instructive though; aluminum to mach 3,
titanium to mach 4.5, inco to mach 5.7.
That is for missile design though; heating depends a lot on what
direction you're flying through air and at what altitude.
On Wed, Apr 5, 2017 at 6:44 PM, Troy Prideaux
<troy@xxxxxxxxxxxxxxxxxxxxx> wrote:
You might be able to BOE the leading surfaces maybe(?) by doing agather a
temperature conversion of the RMS velocity of the air molecules to
ball park number?rocket
vrms = sqrt(3RT/Mm)
R = molar gas constant = 8.3145
T = Ambient Temperate of the air = 298 Kelvin
Mm = molar mass of the air in kg per mole = ~29 for air
So air molecule vrms = sqrt((3 x 8.3145 x 298) / 29) = ~506 m/s (ie
in ambient temperature in a stationary position)we
Rearranging for T at… dunno say Mach 2 which let’s say is 670 m/s so can
assume the vrms hitting the leading surfaces would be approx. 506+670 =1176
m/s ?be
So now rearranging:
T = (vrms^2 x Mm) / (R x 3) =
(1176^2 x 29) / (8.3145 x 3) = ~1608 deg K
Converting to say deg C = 1608 -273 = 1335 deg C
Which seems a bit high? Dunno?
As has been mentioned, the exposure is only temporary and heat*ing* will
proportional to air density which is obviously reduced as you increase inOn
altitude.
Troy
From: arocket-bounce@xxxxxxxxxxxxx [mailto:arocket-bounce@xxxxxxxxxxxxx]
Behalf Of Ken Bibatools
Sent: Thursday, 6 April 2017 10:34 AM
To: arocket@xxxxxxxxxxxxx
Subject: [AR] Re: AR Nose Heating (was:. 3D-printed RL-10)
We've tried to do some CFD calculations to get a better idea of heating
effects in the sounding rocket performance domain. A challenging project
but if there is a university team with access to good (and expensive!)
- love to collaborate.measured
As Chuck says, our experience validates other amateur experience. The
heating effects are more modest than rumor suggests. More data of
heating effects would be a goodness.nosecone
Of course, there ARE ways to make the heating effects worse. Wrong
shape. Too much attempted acceleration low in atmosphere that directsskin
motor energy into heating.
K
Ken Biba
Novarum, Inc.
415-577-5496
On Apr 5, 2017, at 5:14 PM, Redacted sender "crogers168" for DMARC
<dmarc-noreply@xxxxxxxxxxxxx> wrote:
You can calculate the radiation equilibrium temperature on the nose cone,
and get a very high surface temperature. But this is analogous to the
temperature of an SR-71 in cruise.F
Analogy for a sounding rocket type heat exposure like this, is a 750 deg
to 1,000 deg F oven, you stick the rocket in for 20 seconds and thenpull it
out. Much lower temperature. Unfortunately much more detailed analysisto
get the time dependent thermal effects on the surface temperature.little
As Ken mentioned, many high power rockets have flown to Mach 3, and a
over, with metal nose tips and composite nose cones.stretch
Example below is the Derek Deville Qu8k Q motor rocket, which used a
fiberglass nose cone with aluminum end plates, and a stainless steel nose
tip. Replacing the fiberglass with aluminum could probably easily
this configuration to Mach 4.Note
<Qu8k.jpg>
http://ddeville.com/derek/Qu8k.html
Main advantage of Inconel versus a high temperature steel is weight.
from the Qu8k rocket that the steel nose tip is only part of the nosecone,
weight savings from Inconel will be minimal. And the extra weight fromrocket,
using high temperature steel is literally at the best point on the
the nose tip, moving the CG forward.Mach
Chuck Rogers
-----Original Message-----
From: KEN BIBA <kenbiba@xxxxxx>
To: arocket <arocket@xxxxxxxxxxxxx>
Sent: Wed, Apr 5, 2017 4:43 pm
Subject: [AR] Re: AR Nose Heating (was:. 3D-printed RL-10)
Our experience in flying to the 100k’+ region with peak speeds in the
2.5-3.5 domain suggests heating highly overrated. We are flying largelythe
composite airframes with modest grade epoxy with composite (fiberglass)
nosecones with an aluminum tip - VK shape.
We have seen no signs of nosecone heating … and the only heat effects on
airframe we have seen has been on heavy paint on the sustainer bodyabout 3’
back from the nosecone tip .. where it appears the shockwave returns tothe
body. It got a bit smeared. Hope to actually, finally fly anheating is
instrumented nosecone this summer to measure nosecone heating.
K
On Apr 5, 2017, at 4:33 PM, Team Icarus SDSU <rocketteamicarus@xxxxxxxxx
wrote:
This question is also of interest to our projects.
It's a couple years from launch, but Icarus 3 is likely to remain in the
M=3.0-4.0 range for the first 100,000' of its flight; significant
expected. We need to perform more in-depth analysis, but the currentplan is
to build the dart section from lathe-turned inconel.the
Alex Lewis
On Tue, Apr 4, 2017 at 6:22 PM, William Claybaugh <wclaybaugh2@xxxxxxxxx
wrote:
Do (AR) nose tips see the kind of heating that would require inconel or
like?the
I've wondered if USC/RPL's titanium nose tips are justified for a Mach 5
mission w/ a very short heat pulse....
To be clear, I have not done my own analysis, I'm asking two questions.
Bill
On Tue, Apr 4, 2017 at 7:01 PM Ben Brockert <wikkit@xxxxxxxxx> wrote:
I visited Atlantic Precision a couple years ago, one of the few shops in
US with multiple EOS DMLS machines, and they were actively printing partscheaper
for the RL-10 even back then. Printing the chamber is big and flashy, but
there's a lot of utility in cranking out highly detailed inco or haynes
parts.
For any part with moderate complexity of the nickel alloys it's now
to print and lightly post-machine than to machine from solid material,even
at small production quantities.alloy
That is of relevance to AR because a one-off printed and sanded nickel
nose tip for a higher performance hobby rocket should quite affordable,they’re
especially if you shop around and make it clear that you're not in a rush
for the part.
On Tuesday, April 4, 2017, Dave Klingler <davek@xxxxxxxxxxxxxxxx> wrote:
Ehhhh…one can always ask. Sometimes people like to talk about where
headed. :)wrote:
Dave
On Apr 4, 2017, at 1:17 PM, William Claybaugh <wclaybaugh2@xxxxxxxxx>
read,
Dave:
Anyone privy to such information is likely subject to a non-disclosure
agreement....
Bill
On Tue, Apr 4, 2017 at 12:24 PM Dave Klingler <davek@xxxxxxxxxxxxxxxx>
wrote:
I just saw an article over at parabolicarc about AJR's first 3d-printed
thrust chamber firing. I’m trying to decide whether, from what I’ve
they’re substituting copper for stainless in a few spots.materials
I think design changes are probably unlikely this early, but at the very
least the new manufacturing process opens up the way for different
and more elaborate cooling passages that wouldn’t be possible using theold
tube benders. Is anyone on this list privy to what sort of plans AJR hasthe
for higher chamber pressures or other improvements to the RL-10? What’s
schedule for doing complete engine certification?
Dave Klingler