Question?

[Chadly33]

Wouldnt the heat output of a valveless be better used to add to the thrust, by using the engine as a superheater for a steam rocket ? Could you simply encase the CC allowing a nozzle to be formed around the exhaust pipe and spray in water between the two cases with a one way valve on the feed line? Causing steam to be let out at high pressure aka steam rocket ?

[Sebastian LFT]

That's an awesome idea !!. Sounds like you got another project a brew'n

[Mike Everman]

I've been there a bit. Conclusion is that your tailpipe will crush if done that way. Better to make a center body with your nozzle in the middle, and the exhaust pipe outside and therefore annular. I made one like that and took it to Graham and Nick's test site but couldn't get it started. (It didn't have the steam nozzle yet, just wanted to get the motor to go, and I'd finished it the night before going to the UK.)

[marksteamnz]

You have to get the water in ( a lot of water) at a pressure higher than it is going to come out if you are looking at feeding a jet on a continuous basis. Or you need a strong vented container to fill with water and then seal. Heat in = minutes, Thrust = seconds. Mass flow vs heat transfer is a bear.

Wouldnt the heat output of a valveless be better used to add to the thrust, by using the engine as a superheater for a steam rocket ? Could you simply encase the CC allowing a nozzle to be formed around the exhaust pipe and spray in water between the two cases with a one way valve on the feed line? Causing steam to be let out at high pressure aka steam rocket ?

[Chadly33]

I thought more along the lines of the water pumped in a larger volume giving a slight moment before it superheats expanding enough to shut off the oneway feed valve exiting the nozzle creating a vacume inside the expansion chamber for the next load of water to dump in? I thought it would run more like a pulse engine using steam as fuel and the inlet (oneway valve) as the equivilent of a valved engine. Of course the area for expansion (The outer CC body) Would have to be tuned to the amount of water dumped in as well as the nozzle size! Ive got plenty of oneway valves good for 1500 psi.

[Vermin]

The dificulty with using water in its natural state is that it contains dissolved minerals, any enclosed chamber would have to be cleaned of the built up residule scale, unless of course you were to use deionized or distilled water, it would probably be best to inject directly into the cc where the scale can be ejected with the exhaust. Steam propulsion is viable, but If i remember correctly the process utilizes hydrogen peroxide and a silver catalist, the concentration of peroxide is very very nasty stuff to play with.
V

[Graham C. Williams]

Mr Jim Bamford (http://www.onthewire.co.uk/bamford.htm) developed a boiler for his flash steam hydroplane.
From the Book Experimental Flash Steam, J.H. Benson and A.A. Raymond. Tee Publishing.
I Quote "The 'Bamford' venturi-type boiler is undoubtedly the most efficient steam generator yet devised for model hydroplane work.' 'It is really a blowlamp and boiler combined, and all air necessary for combustion passes through the venture. Forward motion of the boat assists the natural injector effect. In Frank Jutton's version of this boiler combustion improves considerably as the boat builds up speed."
I'm sure you can see where this is going---"The boiler was efficient but made an extraordinary booming noise which could be heard over a considerable distance. It was thought that this phenomenon was due to the venturi and boiler acting as a kind of pulsejet.""
As to steam Pressure: "About 2000 psi was the normal working pressure on an experimental turbine plant." " Jim Bamford has recorded over 4000 psi in a model steam plant"

As a young man I saw a hydroplane with this boiler run; not the original, that was before my time but a copy . From our point of view Jim had made a boiler that utilised the properties of non-steady combustion.

Graham.

[Ghrey]

I have thought about this idea lately as well, ( last 6 mos ), but have not done any thing in the way of design or testing. No space or time.

I will follow your inquiries with interest.