Steam rocket project

[GRIM]

Hi Anders ,
Congratulations , very cool , the plume from the nozzle looks spot on ,
the pilot of this vehicle had better hold on real tight , thats a lot of thrust ,
seen the logs an leafblower used before , , very good .

[Johansson]

Thanks, the rocket sure pulls good. It will be interesting to see how the rocket reacts to acceleration since the water should pool up at the rear of the bottle instead of in the bottom as it did now, in the video it can be heard a clear change in tone and also be seen a difference in the jet plume compactness after 4 seconds which might be steam mixing with water in the nozzle.

[tufty]

"pushes good", surely?

Anders, you're a maniac. And I mean that in a really good way. Can't wait to see video of this on the lake.

[Johansson]

Ha, you must be the first to say that in a good way...

Now that I think about it we should perhaps do the next run with the front end of the kick slightly raised to simulate G-forces on the water just to see how that effects thrust and jet plume appearance.

[Johansson]

We decided to test the kick on the lake today.

The ice was 5cm thick so even though it cracked and made sounds when we walked on it we decided that it was safe to ride on. Without knowing anything about the kicks performance we rode two on the kick to bring the acceleration down a bit, if we knew what would come we would have made a single ride but more about that later.

We took the pressure to 65 bar knowing that it would drop about 10 bar before we had carried the kick down to the lake, I used a piece of board to sit on and operated the valve by hand. The kick accelerated well for aprox. 100m, then there was another 100m of low thrust that kept us cruising at constant speed before the kick started to slow down and came to a halt 300m from the start. The GPS recorded a top speed of 60km/h so without the passenger it should hopefully go over 80km/h, enough to get some wind through the beard at least.

After lunch we decided to give it another go without the passenger but found that the valve seals was damaged, as soon as the pressure started to rise it leaked water through the ball valve so we aborted the run.

Back home we took the valve apart and found that the seals that were made of nylon had started to melt from the steam heat, I will make a bunch of them on the lathe so we can change to new ones after each run to avoid this problem in the future.

Another interesting Saturday has passed. =)

http://s231.photobucket.com/albums/ee19 ... V03913.flv

[tufty]

Oh yeah! Must be getting on for time to test the 'chine for real, no?

[Johansson]

It is getting closer and closer, M, GRIM and I are working on a way to solve the cold weather problem with the Thunderchine (or any other pulsejet for that matter) since propane is out of the question. Things are looking good so hopefully I can update the project thread soon.

[Johansson]

I´ve rebuilt the valve with O-rings since nylon gaskets is not the best choice for use with overheated steam, I tried it with shop air and it is leak free up to 6 bar at least. We´ll do a real test later to find out how it works with the heat.

The best thing about this is that if a gasket gets damaged I won´t have to make a new one on the lathe, I just take the valve apart and drop a new O-ring in. At the race we won´t have access to a lathe so we need to have engines that are easy to maintain.

[Viv]

Hi Anders

Got to love your work on this project, I wondered about adding an ejector to your kick combination to boost thrust and shield your toes there is a fair bit of stuff written on ejector rockets but apart from a hydrogen peroxide experiment i have not seen any thing based on a steam rocket

Viv

[Johansson]

Not a bad idea at all, the steam rushing out at around the speed of sound should be able to pull a fair amount of air with it to boost performance quite a bit.

Nevertheless, the track is 2000m long and the rocket will run out of steam after 200m so this project is intended to be more show than go. An ejector fitted after the jet nozzle might give more thrust but it will also block any view of the steam plume, so I think that we will settle with what we have for now and focus on the pulsejets and gas turbines we are working on for our other rides.

It is very fascinating that the rocket can be fuelled by some water and a pile of wood, a hybrid rocket of the same specific impulse would have consumed N2O for almost 100 euro and we ran our rocket practically for free. Imagine a larger steam rocket with 100L capacity and the same burn time, talk about a horse kick in the ass!

[marksteamnz]

http://www.rocketbelts.americanrocketman.com/steam.html

Another Steam rocket link. Applogies for not posting earlier but a hard drive crash removed all my interwho bookmarks and I just stumbled across again this today.
Cheers

[Johansson]

I can´t get the link to work unfortunately.

A friend has been offered a 50L Argon bottle for free, so we are thinking about building an even larger rocket engine from it. 200kg thrust and ~5sec burn time would make a nice crowd pleaser.

[ace_fedde]

I can´t get the link to work unfortunately.

Strange, works for me. Great site, beautiful steam rocket!! Try again!

Fedde

[Viv]

Hi Anders

The link works ok for me too, some interesting old pressure jet pictures too, that 50l bottle will be bit of a monster, what valve will you use?

Viv

[Johansson]

Ahh, now the link works. I must have had some problem with the computer at work. Thanks!

I am not sure how to build the 50L rocket, but a 1" hydraulic ball valve should do the trick if I rebuild it for O-rings.