20 replies to this topic

[chrissw]

Does anyone know of anybody experimenting with small liquid fuel rocket engines in the uk?

I suppose one would have to be lucky enough to own an isolated farmhouse with a couple of barns/outbuildings one could utilise for a workshop and test-chamber, ie not many of us would qualify!

[smpip]

What research have you already done?

[shadow]

This is a very advanced subject that requires a lot of thought and science and skill.:flames:

[Edited on 5-8-2003 by shadow]

[smpip]

And an official licence, unless your planning to make stealth/under the RADAR ones?

[Richard H]

Dont need a licence. Liquid fuel rockets are not affected by explosives law legislation as the fuel and oxidising agent only meet at the point of combustion.

[smpip]

Ain't it in the little orange book?:duh:

[smpip]

Yep its in the book,

UN No Desc HAZCAT
0395 Rocket motors, liquid fuelled 1.2J
0396 Rocket motors, liquid fuelled 1.3J


Haz No 1.2= Substances and items which have a projection hazard but not a mass explosion hazard

Haz No 1.3=Substances and items which have a fire hazard and either a minor blast hazard or a minor projection hazard, but not a mass explosion hazard

The J catagory refers to an item containing both an explosive substance and a flammable liquid or gel

But is it all exempt ?

[Richard H]

That is a commercial item you ninny. Amateur liquid rocket motors are not covered.

[smpip]

Excellent:bounce:

Is there any limit to size?:bounce:

[Richard H]

Only airspace limits what you can fly really. Generally to launch a high power rocket you should request a NOTAM to warn aircraft you are launching in a certain area.

[chrissw]

re: <Dont need a licence. Liquid fuel rockets are not affected by explosives law legislation as the fuel and oxidising agent only meet at the point of combustion.>

Many thanks, I thought this was the case, I was told that liquid fuel rocket engines are considered in law as a form of "internal combustion engine" and as Richard has said, the component liquids only come together to form an explosive mixture in the combustion chamber ( as do petrol and air in motor car engines).

Basically this could mean that the law doesnt see them as being any different from car engines and as thousands of amateur mechanics "tinker" with car engines in their garages on Sunday afternoons, theoretically the law cannot stop anyone from experimenting with liquid fuel rocket motors either.

Of course one requires certain specialist knowledge first (which I for one dont have so I think I'll stick with my land-rover engine on Sundays, at least for now) and one could very quickly fall foul of other aspects of suburbian law - ie noise, pollution, simply scaring the living daylights out of one's neighbours, etc. In fact I think the old "pulse-jet" motors fell out of use because of noise levels?

[Robbie414]

You are right, there is no licence required for exactly that reason, but you do need to be on a farm!

I have built a couple of pulse jets, which incidentally are fantastic....fingers in ears!! And a gas turbine based on a lorry turbo unit...mmmmmmm the best sound and smell on earth if you ask me! Feel the power!

Liquid rocket motors are another league though, yes you need some major skill in metal working. You also need to be a fairly competant engineer when it comes to calculation of heat expansion and stress. You need some pretty serious pumps and some potentially nasty chemicals, or good old H and O.

Tell your neighbours what you are upto in your garage if you are in a built up area, as they will no doubt be calling in the army when the hear your first flame out 'BANG'. If you are thinking about taking this to the next step and actually installing a motor into a fuselage, then good luck my friend, and please let me know how you get on! Bear in mind that because Liquid fuelled rockets can reach very high altitudes you should really get in touch with a club who has annual events at which NOTAM is sorted for you. But I would be very impressed if you even managed to get one to lift off successfully!

have fun!

[smpip]

What about gravity fed fuels, like a rather famous (or should I say infamous Von-brawn or was it brown?) his first demonstration model was just two tanks (made to exacting standards I am sure) with one way valves (very well machined) and used two spontaneously combusting products that did their stuff once introduced into the combustion chamber below?

"It is exactly 75 years since Dr Robert H. Goddard successfully launched the first liquid-fueled rocket on 16 March 1926."
I just got this from a web page, so it was not Von-oogeemaflip that did it all first

Edited by smpip, 15 August 2003 - 06:50 PM.

[Robbie414]

Don't really know much about von whats-his-flip (Wernher Von Braun) except that he pioneered the V2! Which was a liquid fuelled rocket! (alcohol + Liquid O2, and did not spontaneously ignite) I should imagine his later fuels where something like a Hydrogen Peroxide based fuel.....if true then you would need to be able to get your hands on a good silver mesh catalyst to decompose the fuel, (adding something like a petrol or parafin spray which is ignited by the heat of the steam and pressure created by the HTP decomposition would double your thrust)...however due to the conditions your silver cat' will only last a couple of hours. You still need pumps as "gravity" would not provide anywhere near enough pressure to force the reactants into the combustion chamber.

Other liquid fuels include Hydrazine, Nitric Acid, Sulp Acid...and lots of other very very nasty chemicals. Which still need to be pumped.

The HTP method would probrably be the safest due to the low toxicity and ease of use, however you must be aware of chemical incompatabilities plus the fact that Hydrogen Peroxide reacts with many elements to form explosives!

Liquid fuelled rocket engineering is really not for amateurs, but if I were to build one at home it would be a hydrogen and oxygen based system...and in my opinion that would be the safest and easiest.....still very very dangerous! A nice touch would be to allow the liquid oxygen (very cold) to circulate round the combustion chamber and nozzle (car engine water jacket style) to heat the gas and cool the metal of the chamber/nozzle.

Edited by Robbie414, 18 August 2003 - 12:38 PM.

[smpip]

Von Braun used Hydrogen peroxide with Naptha disolved in Ether, these combust upon contact with each other and it was used in a demonstration unit, that was simply two fuel chambers and a combustion chamber with strategically placed one way valves, gravity fed, How, could this work,I hear you ask!!!!
Well even pulse jet engines need fuel and they have strategically placed valves, and which ever direction they were traveling in, they created their own "gravity".