ALICE Purdue PSU

[nouveautesdu78]

But doesn't it produce any nanoparticles from incomplete combustion ?

[doverdx]

Also, it looks like your propellant preheating is dominating your deflagration process. An opacifier added to the H2O may help with that.

[doverdx]

To help with your redox efficiency and two-phase characteristics, a Al/Mg alloy (few %) may help reduce mean droplet sizes and improve combustion stability when residence times are small (such as in your application). Depending on your adiabatic temperature and particle Fourier number, you may be able to induce droplet spalling as the droplet becomes unstable from the Mg phase transition inside the alloy. However, this increases the pyrophoricity of the propellant so be careful.

[1ukjunglednbraver]

i mixed a bag of german dark al with water in my room after reading fire hazard in contact with water on the packet....i didnt do anything at first but after about 2-3 minutes it all kicked off bubbling gas spurting crap all over the place what a mess thankfully it didnt go rocket fuel on me

[sfson5]

@1ukjunglednbraver That's why they say not to mix it with water....

[1ukjunglednbraver]

@sfson5 yeh at first i was adding it slowly and then i thought this aint doing anything so i put the whole bag in and well.....you live and learn

[netsight]

Fascinating stuff indeed, tell me has there been any further development with the project with regard to the possible usage of additional additives to increase fuel energy/kg - like for example enriching the oxygen content in the precooled water solution? or utilizing a Ga/Au nanoparticle alloy (if the alloy could be stabilized under temperature) ?

[sfson5]

@netsight Yes, we are working on several variants to increasing energy/performance. We have not looked at Ga/Au alloys.

[XSAlexio]

Nice work. I remember having exactly this idea a couple of years ago but I figured it would be inefficient because of preoxidation.

Have you measured how much Al is preoxidized before it is frozen? By the way, what is theoretical specific impulse for an Al-H2O rocket?

[sfson5]

@XSAlexio If the aluminum is adequately passivated to start with there is very little oxidation that takes place if the mixing is done cold. Also, oxidation inhibitors can dramatically decrease this problem.

[XSAlexio]

@sfson5

Thanks very much! Do you have an idea on what inhibitor to use? I take it you are using distilled water now (which makes good ice crystals). What inhibitor would allow you to keep good integrity?

By the way, how about gelating the whole thing with inhibitors in it? Keeping it cool but not frozen...

[sfson5]

@XSAlexio We are looking at some that are used in water based paints for flake Al. That's still a work in progress. Not freezing it is possible, but you need to make sure to use it right away or prove it is stable for the storage time. Freezing shuts the reaction down essentially.

[Nighthawkinlight]

Pardon my assumption that this was a hybrid engine. I did not realize this is a solid thermite-like propellant.

[Nighthawkinlight]

What benefits does this propellant offer as opposed to more traditional fuels? I assume this is meant for a hybrid engine, using the solid Al/H2O fuel oxidized by O2 or N2O? Is the ice used because it produces more gas volume than comparable binders, or is it a matter of low cost? Is there trouble with the fuel grain softening due to rising temperature before it is fully consumed? Can the gas flow be cut to kill the burn then safely restarted again as can be done with other hybrid engines?

[TreyRust]

2:29 instant steam room :)

[shmalphy]

it doesn't take rocket appliances to figure this out...

[mrdotbeezle]

Hey, very impressive stuff! Did you make those Al-nanoparticles yourself and if yes how did you reduce the Al-Substrate?

[sfson5]

@mrdotbeezle No, we purchased the nano Al from NovaCentrix.

[brfc1993]

I used this to power my rockets on my Shopping cart.

[zyxwvutsrqponmlkh]

Was 80 nm calculated to be best or was it just what you had access to?

[sfson5]

@zyxwvutsrqponmlkh No, it is not optimal in several ways. However, micron sized Al does not work with just water.

[sigma1o1]

@sfson5 quite impessive ,but if specific impulse can still be incresed with hydrogen mol or some other

[sfson5]

@sigma1o1 Yes, could be improved with other ingredients.

[jpourkav]

my compressible flow professor handed out the paper for this project.. Very Impressive!!

[sfson5]

@kavazci

The peak Isp measured was near 210s, overall ~160s.

[kavazci]

Annoyingly simple & obvious extension of using aluminium fuel (as are most great leaps forward). I realise this concept is for re-fuelling out in space (aluminium source???). However, on Earth, would/could LOX be fed in jet-like, to oxidise the hydogen formed from Alice, thus further increasing SI, or would this be in some way counter-productive?

[sfson5]

@kavazci

Dissociation at even higher temperatures would limit the usefulness of that approach.

[romfeastore]

can you please explain mee how it is possible to mix aluminium and water without explosion?

thank you

[sfson5]

@romfeastore The aluminum used has an oxide layer. When this is mixed cold and then frozen there is very little reaction that occurs until it is ignited.

[smoothjamskillmoure]

Does this work better now than, what is it compressed liquid oxygen that they use on the big boy rockets? I ask because I want a way to propell my body into space when im dead without recruiting NASA. or Virgin, :) haha jk well the second part at least.

[sfson5]

A liquid oxygen based motor would be much better than this. This concept has a lot of work ahead to be used. Sorry, you'll have to keep talking to NASA or Virgin concerning you ashes. :^)

[smoothjamskillmoure]

Haha, well maybe space flights will be much cheaper by the time I get older but it seems doubtful. Did anyone else have this idea of being sent into space after dying? ever since I first read of black holes I wanted to be shot into one, preferably when It wont be so painful to be supercompressed, maybe It will reanimate my ashes in another demension??? Who knows! Just gotta wait the 1600 light years till I get 2, V 4641. well worth it.

[smegnose]

Wow it peaked out at almost 800 lbt. I'm guessing the tube assembly was about 20lbs? 400x ratio is nice.

[sfson5]

It was heavier due to the custom motor for pressures up to 2000 psi.

[deutschmasta1693]

awesome! my dad's on youtube!

[reasoning777]

I think this was a great vid! I have no knowledge of rocketry and or fuel, but the faces show a justifiable satisfaction, and that to me, gives an insight to the 'heart' behind the project which is so nice to see in this day a £'s & $'s and rush to the bottom line attitude. Really nice, and well done!, also to the young man who made the music eh!

[OldManDotes]

What's the specific impulse of the ALICE fuel?

[Blake687]

Would anybody here happen to know the music used in this?

[sfson5]

My son Jacob made the music usind Garageband. Free music!

[Blake687]

Do you know where I would be able to find it (the music) at?

[sfson5]

The only place it exists is in this video clip and in my iTunes. Do you want an mp3 of it?

[Blake687]

Sure, that would be great. :D

[sfson5]

Ok. Post your email address and I'll email the iTunes *.m4a file. I'll reject your reply so your email won't appear here.

[benjojo12]

h-h-h-holy shit. What is the after product?

[sfson5]

2Al + 6H2O -> 2Al2O3 + 6H2

The H2 will react further with air to form water.

[3azzamy]

nice

[TheSchmidi093]

How high was the flight with the commercial motor and how high with ALICE.

[sfson5]

There were other reasons for a fuel-lean mixture -- easier to cast and less alumina produced primarily. We do hope to pursue hybrids with AlH3 and other high hydrogen materials; as well as liquids.

[selwyndog]

Hello me again, I'm presuming the composition is optimized for an exhaust temperature slightly below the melting point of Al2O3, thereby running rich in the oxidizer.

Any development in terms of a hybrid rocket using water as an oxidizer and a mixture of AlH3/MgH2 as a fuel?

[selwyndog]

I want a go! Can the exhaust be mixed with atmospheric oxygen in some sort of nozzle/ramjet type configuration to improve impulse?

To aid combustion is any sort of agent added to strip away the oxide layer present on the Al to increase reactivity/lower temperature at which it starts to burn?

[sfson5]

You could mix atmospheric oxygen in some sort of configuration, but because the product temperatures are already very high, dissociation would limit much improvement in impulse. If the products were combined with other fuels there may be some overall benefit. Also, the formulation could be changed to be very fuel rich and that may be viable. There is no agent added to strip away the oxide layer. Coatings and other approaches are of interest for future work.

[sfson5]

Yes, we mix Al with liquid water and then freeze it.

[SrlePopovic]

I'm not sure that I undesrtand the way how you perform mixture of this two components ? Ice and Al...

How you produce this mixture ?

Do you mix Al it with water and than freeze or what

[nashbf161]

The reaction between Al and water seems to very explosive. Do you think you can you make it more controllable to apply this new propulsion/thrust for aeroplanes.

[sfson5]

The burning rate is fast.  We can modify that is several ways, including changing the particle size.

[marcerosario]

Congratulations! :-)

[newaysfactory]

Ok thanks! So it's similar to Zn - S reaction, but more exotermic!

Is it Difficult to ignite?

[sfson5]

Yes, it is difficult to ignite.  In some ways similar to Zn-S. Al-ice would produce more gas also.

[newaysfactory]

Well done boys!

One short question!

What is the reaction between ice and aluminium?

[sfson5]

Al + H2O -> H2 + Al2O3 + a lot of heat (ideally anyway).

[sfson5]

2. The final vertical configuration static test produced a peak thrust of approximately 650 lbf at 2000 psi with a specific impulse at these peak conditions of 210 s, close to that predicted for this propellant formulation (not optimized). Integrated over the one second burn duration, the total impulse produced by the ALICE grain was 1470 N-s (330 lb-s), resulting in an overall specific impulse in the range of 150s. Modifications of the propellant could improve this. See papers referenced.

[Wxweenie91]

Two things...

1. at minute 1:45 in the video is the non-thrusted particles remainder Al or is it the container melting from the heat inside.

2. Have you determined the ISP of Alice..

[sfson5]

1. I don't think it is the container based on looking at the container afterward. The nozzle gets coated with alumina (Al2O3). Perhaps some of this alumina is coming off?

[sfson5]

Here are references to our most recent papers on Al-ice:

Aluminum-ICE (ALICE) Propellants for Space Propulsion

Grant Risha et al.

AIAA-2009-4877

45th AIAA/ASME/SAE/ASEE Joint Propulsion Conference and Exhibit, Denver, Colorado, Aug. 2-5, 2009

Combustion of Nano-Scale Aluminum and Ice Mixtures and Solid Rocket Feasibility

Tyler Wood et al. AIAA-2009-4890

[sfson5]

Atevra, also we think based on French work (SNPE) that using at least some micron aluminum is possible. We certainly have a lot more work to make this plausible and efficient.

[Atevra]

Interesting, thank you for this video as media articles on this kind of topic are not very useful!

Now how much does Nanoscale Aluminium cost per Kg? a few grand?

[sfson5]

Thanks. It's true that media articles do not communicate science and technology very well. The nanoscale aluminum that we used is expensive. I'm told that the power required to make the nano-aluminum is comparable to the cost of the power to make micron-aluminum. If this is true, then at scale the cost would be comparable. Also, the size of a reactor to make nanoscale aluminum is not large. Consequently, you could think about making nanoscale aluminum on mars or elsewhere.

[quantumG]

Well done.

[sfson5]

Thanks.