Interesting. By the pictures on their website, it looks like they were doing test firings on the Aerotech test stand.
https://www.adranos.com
Did the lithium component decrease the D-ISP or was there sufficient performance increase to offset the low density of the lithium component?
Interesting. By the pictures on their website, it looks like they were doing test firings on the Aerotech test stand.
https://www.adranos.com
So are you planning to start making and selling motors with this propellant to us hobbyists? Does this propellant have higher ISP than Propellant X?AeroTech/RCS has an exclusive license to use Alitec in hobby rocket motors.
I just ran a quick n dirty PROPEP 3.0 on a hypothetical 10% Li, 10% Al, 64% AP, 14% R45, 2% E744. Isp is 250-259. Virtually the same result was obtained by removing the lithium and adding another 10% aluminum.It would be interesting to run the formulation through a thermochemical simulation like NASA-Lewis and see the theoretical results.
Is this one of those propellants that is only worthwhile in larger motors where the metals can burn properly in chamber?
So are you planning to start making and selling motors with this propellant to us hobbyists? Does this propellant have higher ISP than Propellant X?
Maybe the amount of free hydrogen in the exhaust might be going up, lowering the average molecular weight in the exhaust increasing gas exit velocity.
I just ran a quick n dirty PROPEP 3.0 on a hypothetical 10% Li, 10% Al, 64% AP, 14% R45, 2% E744. Isp is 250-259. Virtually the same result was obtained by removing the lithium and adding another 10% aluminum.
Density of the lithium-containing mixture was quite low, 0.0498 lb/in^3. With all-aluminum it's 0.063.
Since Aerotech has indicated significantly-higher performance from ALITEC, a working hypothesis is that the Li in the alloy aids in combustion of aluminum inside the chamber rather than outside. That is consistent with the flame shown on the Adranos web page; high-aluminum propellants usually produce a fairly bright white flame, from aluminum particles that exit the motor before combustion is complete.
The chemistry that reduces HCl in the exhaust is going to be interesting. The chlorine *has* to go somewhere (rocket flame is hot, but not hot enough to transmute an element ). PROPEP shows a great reduction---three orders of magnitude!---in HCl in the exhaust. It appears that much of chlorine in the exhaust would be in the form of gaseous Li2Cl2.
Best -- Terry The Generator Of SWAGs. (scientific wild-@$$ guesses)
An additional benefit may be reducing or eliminating the tendency for burning Al to form its own impermeable shield of Al2O3 protecting the melted aluminum droplet from further easy combustion. That may be another source of improvement, poisoning that protective shell, reducing the required residence time. Likely other alloying constituents could do the same thing. I know of at least one that I think would work, but it isn't nearly as good a fuel as Li.
Sorry, I haven't read the link yet.
Gerald
It must be because from what I found you can't dissolve that much lithium into the aluminum.That might also indicate that the lithium is crystallized independently of a true solution.
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