This question is somewhat ignorant as I don't have a lot of experience with
methane (or LNG) but does it produce a thermal barrier similar to RP1/Jet-A? I
find that the thermal barrier seems to be one of the most appealing aspects of
using refined hydrocarbons over something like ethanol but I've not really
considered methane. Methane does seem to have a slightly higher ISP then
RP1/Jet-A albeit with roughly half the density.
On Tuesday, April 4, 2017, 8:54:26 AM EDT, Brian Feeney <alaiadesign@xxxxxxxxx>
wrote:Both Blue Origin and Space X are using Methane in their new engines
currently under development.
Again both say they are shooting for very high reusability rates, rapid turn
around times measured in hours and 100's if not 1,000 cycles plus target in the
case of Blue.
I assume they must be using a high purity form of methane as described by Henry
Spencer to reduce the chances of coking, corrosion with the copper inner
chamber...
Can one get a non stenchant form of purified methane in bulk and or would they
both have to purify it (remove Mercaptans, any polymerizing compounds etc)
after taking delivery. i.e. is it legal, safe to road transport in bulk in a
purified non odour form.
CheersBrian Feeney
On Tue, Apr 4, 2017 at 12:30 PM, Henry Spencer <hspencer@xxxxxxxxxxxxx> wrote:
On Sun, 2 Apr 2017, Graham Sortino wrote:
Is there any general guidelines in terms of the temperature or pressure at
which point coking in coolant channel occurs when using Jet-A (ie. some kind
of max temp and/or pressure to avoid)?
Never heard of anybody looking into that, although it's not something I've gone
looking for. Possibly there might be something to be found in studies of fuel
stability in high-supersonic and hypersonic aircraft (where friction heating
can get fuel in wing tanks pretty hot) -- not quite the same problem, and often
dealt with by using special fuels, but it might offer some hints.
It would be tricky to get good numbers for something like Jet-A because there's
so much variation in its exact composition.
Henry
