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Hot Rod Job For SpaceShipOne
rwven writes "MSNBC is reporting that the engine on SpaceShipOne has been modified to provide more thrust, for a longer amount of time. Mainly, the Nitrous Oxide tank has increased in size to lengthen the amount of time before the dropoff of thrust when it goes from a liquid to a gas. Also reporting is Space.com."
One line blog. I hear that they're called Twitters now.
" Can somebody tell me what nitrous oxide does in a car engine? It's not a flammable gas, is it?"
In a word, oxygen - nitrous contains more oxygen than air and is in a highly dense liquid form. In a car engine, nitrous, along with additional fuel is squirted into the intake. In the hybrid rocket engine, a large cylinder of rubber is the fuel; the nitrous is the oxidizer.
Chaos maximizes locally around me.
Usually nitrous oxide systems are set up to inject extra fuel along with the nitrous oxide to keep the correct fuel/oxygen ratio.
As an aside, F&F fans should realize that NOS (Nawz) is the logo of Nitrous Oxide Systems, not a chemical abreviation for nitrious oxide, although they spend a lot of money trying to get their name associated with it.
In conventional rockets, propellant can be pre-mixed -- as in the solid rocket boosters (SRBs) used NASA space shuttle -- or sit in tanks that are filled just prior to launch, like liquid oxygen and hydrogen rockets. In both engine configurations, the are highly volatile and can be toxic to handle.
"The fact that the oxidizer and fuel are not molecularly mixed in these [hybrid] engines, makes them non-explosive," explained Greg Zilliac, a hybrid engine researcher at NASA's Ames Research Center in Moffett Field, California. "We've actually shipped fuel grains by UPS in the past."
Ar is noble, isn't it? So that'd be O2:N2:Ar?
-- Nate
Nitrous used as a drug has been mentioned a lot, so I want to point out that only fire can use this oxygen. To your body, nitrous has no usable oxygen. If you breathe it in pure for too long with no outside source of oxygen, you will pass out/die.
The oxygen component actually provides only a small part of the power increase. NO2 has an extremely high latent heat of vapourisation - in other words it absorbs massive amounts of heat when it is injected and vapourises. This tremendous cooling effect allows a much denser cylinder charge and requires (a lot) more fuel be injected along with the NO2 to maintain the correct fuel/air ratio.
The atmopshere is about 1% Argon. The distribution 21:78:1 is roughly that of an "ideal" human atmosphere. And just because it's noble doesn't mean it doesn't get involved with other atoms sometimes, which may make it a very necessary component to the workings of things.
Wikipedia: Argon
Reinvent the wheel only at either a lower cost, greater effectiveness, or your own personal enrichment and satisfaction.
And just because it's noble doesn't mean it doesn't get involved with other atoms sometimes,
Actually that pretty much IS what noble means.
Chemists have to work fairly hard and use some rather extreme conditions to get noble gases to react with anything.
I'm guessing that wasn't on their radar screen...
What has not yet been mentioned in this /. discussion is briefly, though not directly, mentioned in the aforementioned space.com article. The changes to the engine were made at least partly to offset the previous glitch encountered during the previous flight. "...the increased liquid nitrous oxide should delay that drop off and provide more thrust earlier in the flight, when SpaceShipOne's control surfaces can still bite into the Earth's atmosphere for steering." They hope this will allow them to reach their target altitude this time (almost missed the space altitude last time) without having to resort to secondary guidance systems.
$#!^ happens, but why does it always have to happen to me???
Yeah sure, my head is full of pulsed lasers and extreme temperatures : )
Have you actually seen the conditions under which a compound involving a noble gas will even form, let alone hold together? Chemists get nobel prizes for that sort of thing.
I don't think the conditions inside anyone's head are actually that extreme.
I'm guessing that wasn't on their radar screen...
"It is surely not without interest that no essentially new type of bonding needs to be postulated, and that conventional theories are able to account in a semi-quantitative way for almost all known experimental facts in this interesting series of molecules. It is no exaggeration to say that in principle almost everything described in this survey could have been said thirty years ago." (The Norton History of Chemistry, 1st ed., p. 340)
In other words, it was an accomplishment of open-mindedness, not one of scientific brilliance.
Generally aluminum alloys or fiber. But that's largely irrelevant for this discussion; the key issue with nitrous tanks is that they need to be able to withstand *pressure*.
You can pressurize the oxidizer tank in liquid/liquid biprop rockets, too, but people don't usually do it for large rockets (only small ones). Why? It means that you have to have thick (read: heavy) tank walls, and if you cut corners, you risk a catastrophic explosion.
I was watching this thing on TV about some guy named Hitler. Someone should stop him!
Nitrous oxide suffers from the same problems that a rocket without a turbopump (using instead gas pressurized tanks) suffers from: the tanks need to be built with thicker walls to withstand the pressure, which makes the rocket a lot heavier. While small, simple rockets will sometimes pressurize their tanks, few big rockets ever do - it just plain adds too much weight, and increases the risk of catastrophic explosion if you cut corners.
I was watching this thing on TV about some guy named Hitler. Someone should stop him!
Spoilers break up the vacuume created behind an quickly accelerated car and can actually have a large effect (and at driveable speeds). So putting a spoiler on a FWD car has plenty of effect (providing it is a real aero spoiler and not just for looks).
Now, a wing--which is what most ricers have anyways--will provide downforce on to the whole car, but primarily onto hte back wheels and therefore as you said, will do nothing for a FWD car. The wing also does not help acceleration...it helps cornering by holding hte car down when it is at speed (and therefore COULD help a FWD car). Pushing down on the car actually creates the effect of more weight and woudl decrease accleration, but would apply more grip to the tires at speed. In low speed acceleration (where you're wheels are most likely to lose traction and spin) the wing wont have enough downforce to make a difference...
So yes, a wing is pointless on a drag-civic, but not a spoiler or a full aero kit.
Disclaimer: I am not a honda fanboy...I am however a big fan of german cars and the best example of a real spoiler is the big whale tail on older 911's. And yes, when I see a riced out GTI or somethign with a wing and altezza's...I dont find it anymore attractive than a riced out honda. Just make your cars look right people...if something doesnt fit the image, dont bother.
Bottles.
Alane: I work with LiAlH4 frequently. This solid has to be kept very dry - or sparks will fly. This is definitely unsafe fuel in a manned flight. And it is a very expensive material to burn.
As a rule, custom synthesis chemical companies do not like to work with LiAlH4 on kilo scale - they prefer safer alternatives for large-scale reductions. If they use it, they charge hefty premium because of the safety risks involved.(Unstabilized alane does not even need moisture - it self-ignites on air).
Wall thickness (weight) of the oxidizer tank (for nitrous oxide) can be reduced with moderate refrigeration, -20C for example, which cheap to do and well above the boiling point of N2O (so the engine would still work without need for a turbopump). Nitrous could be stored separately and filled in before flight, refrigerated. Tank would need a safety valve to prevent over-pressure.