Self-pressurized or fizzy à la gox-in-nos?
Fizzy light cryo on both sides of the house looks interesting albeit for
pro-am.
On Thursday, February 15, 2018, Henry Vanderbilt <hvanderbilt@xxxxxxxxxxxxxx>
wrote:
Airlaunch was IIRC going for self-pressurized propane, which is a wholedifferent set of problems than using it subcooled for density.
they got to flight.
Henry V
On 2/15/2018 11:09 AM, Randall Clague wrote:
AirLaunch used propane, and I think they got to hit fire. I don't think
<mailto:ian.woollard@xxxxxxxxx>> wrote:
-R
On Thu, Feb 15, 2018 at 8:42 AM Ian Woollard <ian.woollard@xxxxxxxxx
https://www.freelists.org/post/arocket/LPL-IPA-Effects-on-Copper,5
I don't know that anyone has ever flown propane as a fuel. Google
suggests you have to subcool propane to around 0F to get reasonable
tankage pressure. IRC someone (John Carmack?) suggested it becomes
awkwardly viscous at low temps, but it's possible they were thinking
of propane/butane mixes which wouldn't necessarily behave the same,
but the data on it seems to be behind a paywall and I don't have
access, if you really want to think about using it you should
probably check that.
On 15 February 2018 at 01:15, William Claybaugh
<wclaybaugh2@xxxxxxxxx <mailto:wclaybaugh2@xxxxxxxxx>> wrote:
Evan:
Thanks, I had missed this.
I find myself wondering what an advisor would have said if Henry
II (of England) had asked for an iPhone: is SSTO a technology
that is more economic in future rather than today?
Because multiple analyses show SSTO at a limit price around $50
per Kg., it seems likely to be the preferred answer in a century
or so when demand has reached levels that justify that
solution. The question I’m—in part—trying to answer is whether
a significant investment today can move forward the time when
SSTO flight rates are justified.
In the timeframe of SSTO viability it appears probable that
“peak oil” will be reached and thus that simpler hydrocarbons
may be favored over highly refined ones (because simple
hydrocarbons can be relatively cheaply derived from organic
feedstock). Thus Propane over Kerosene.
Bill
On Wed, Feb 14, 2018 at 1:00 PM Evan Daniel <evanbd@xxxxxxxxx
<mailto:evanbd@xxxxxxxxx>> wrote:
On Wed, Feb 14, 2018 at 1:55 PM, William Claybaugh
<wclaybaugh2@xxxxxxxxx <mailto:wclaybaugh2@xxxxxxxxx>> wrote:
> If we are considering tripropellants, then the Hydrogen
would presumably be
> used as the coolant (optimizing Isp by altitude is
achieved by varying the
> percentage of Hydrogen and Hydrocarbon being burnt). But
that still leaves a
> potential coking problem at the hydrocarbon injectors and
upstream after
> shutdown; a hydrocarbon that evaporates w/o residuals
seems likely to be a
> better choice than one that does not (like kerosene) if
one is looking to
> avoid a post firing purge.
Part of XCOR's approach was to use a kerosene that
evaporated without residuals.
Doug's post on 3/29/17 to this list includes a photo and
AIAA paper:
And a selected quote that the archives don't seem to display:
"...dry-residue-free fuels are strongly advisable, so that
greasy
films cannot be created by fuel spills. We have had good
results in
using 99% isopropyl alcohol as fuel; we even use the same
supply for
the cleaning solvent to prepare the oxidizer plumbing. In the
transition to kerosene based fuels, we have settled on a
grade of
kerosene equal or even superior to RP-1, a
multiply-distilled product
with no non-volatile components. Conventional Jet-A or JP-4
has too
many high molecular weight species, aromatic compounds, and
[too much]
sulfur content to be used in a long-life regeneratively
cooled rocket
engine where low coking is mandatory. The jet fuels leave
long lasting
residues, incompatible with oxygen, if spilled."
Evan Daniel
-- -Ian Woollard
Sent from my Turing machine