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Post by ernie wrenn on Oct 11, 2012 8:17:53 GMT -5
180994010029 ebay item.
Can the fuel be changed to something available?
ernie
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Post by Johansson on Oct 11, 2012 10:01:37 GMT -5
Hmm, I guess that the fuels used are hypergolic so there is no ignition system built in. I think there will be problems converting it to LOX/kerosine since nitric acid is stored at room temps so no allowances for cold temps are considered in the turbo pumps etc.
Propellant metering will be off the scale so I think you are in for some trouble if you decide to try...
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Post by britishrocket on Oct 13, 2012 2:16:22 GMT -5
Hello Ernie,
Interesting question. The fuels it uses are hypergolics and are bonkers dangerous. TG02 that is the starter liquid and the turbopump drive fuel is better known as Tonka fuel. The Germans called it R Stoff in the war to prevent us finding out what it was (it didn't). It is a mixture of several nasties (mostly amines) which if you don't get the proportions right behaves like a big dog. I mean it goes "WOOF!!!"
Trikresol is a methylphenol so again not the sort of girl you'd invite home to meet your Mum.
I suspect you could do what the advert says and banish the turbo pump in favour of pressurised tanks. As Anders says it will get through some amount of whatever you power it with.
The above aside, I can't help but start thinking...Kerosine you can get easily enough, or possibly Petrol (Gasoline). You could also possibly use Ethyl Alcohol. It would have enough cooling capacity if the original coolant was the kerosine/trikresol mix. If you had an engine like this you'd no doubt have a facility to fire it, and you might have access to things like LOX, so you could use that as the oxidiser, pressurised using helium. I think that the trikresol additive is to increase performance anyway. You might not get the advertised Isp but then would you want it? Not sure what the best ignition scheme would be.
It certainly is a beautiful thing. It would be something indeed to see it running.
Carl.
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Post by britishrocket on Oct 13, 2012 6:41:14 GMT -5
I forget to say that obviously the injector would be optimised for the mixture ratio required by the design propellants, and the nozzle will be optimised based on the Cf factor which is in turn dependent on the isentropic exponent on the propellants.
Interestingly the advert doesn't say what the oxidiser was.
Carl.
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Post by britishrocket on Oct 13, 2012 6:42:05 GMT -5
Oh yes it does, nitric acid. I really should pay more attention.
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Post by turbochris on Oct 13, 2012 9:02:04 GMT -5
if you find the fuel, I'll strap it to my back. I'll use my bullet helmet and my shoes with the fins on them.
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wolfdragon
Senior Member
Joined: April 2011
Posts: 287
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Post by wolfdragon on Oct 13, 2012 15:40:48 GMT -5
and that i why i have a wile e coyote plush sitting near the welding bench... just to remind me to make sure its a good idea before i do something...
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Post by britishrocket on Oct 13, 2012 23:48:56 GMT -5
That is prudent.
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