Water vs. Foam

Comparison flights between water and foam in a water rocket.

[AirCommandRockets]

@Spoif- we too were surprised at the difference. We are not sure how foam performs in other rocket configurations yet, but from further flights this weekend for this rocket we keep seeing the same repeatable results. 

[Spoif]

That's a significant increase using foam.   Incredible.

[Olivn]

AirCommandRockets I don't know the altitudes because I unfortunally don't have a altimeter. But It looked like the launchtube and foam combination worked best.
Maybe you can try that as well next time? 9mm nozzle and launchtube and 22mm nozzle and launchtube too? Would be nice to see how much a launchtube helps!
Olivier

[codymierau]

What would happen if you added your extension tube to the rocket with the 22mm nozzle? Would having the second stage give you more height or is it better to have one stage

[simonolschewski]

Why does the hight increases if you increas the nossle area? Of course the rocket gets rid of the energy much faster. And that causes a higher Speed - > higher altitued. But here the air resistent is much higher. With a smaler nossle the Energie is provided over a longer time and the end Speed not so high. But the top Speed is reached at a higher altitued. And the lover Speed means not so much air resistance.
But still the rockets with a bigger nozzles fly higher. Why is that?

[larryupton]

I've watched several of your experiments using foam as propellant. I see the results but I don't fully understand why foam increases altitude performance. Have I missed an explanatory video?

[ComandanteJ]

Could it have something to do with aerodynamic pressure? I dont know the speeds involved, but it seems quite fast, enough to make air resistance a factor. Foam seems to last longer than just water, maybe the water one is flying too fast and hence encountering more resistance, hence wasting more energy?

[RaketfuedrocketsDeutschland]

Great comparison! =)
I didn´t thought that the difference is so big.
The problem with foam in Germany is that it´s kind of illegal, because it destroys the ground of the fields.
Greetings from germany

[The]

Wery interesting. Why do foam increase high of flight? I had observed similar effect with concentrated solution of potassium carbonate. It`s density in 1, 5 times more, than density of pure water.

[MrLuvlingo]

I am curious if it is just mass of the water that increases the distances.  Would salt water also show an improvement?  How about muddy water?

[jsbrocketry]

Hello Air Command, very interesting results with the foam. Even when not using the Jet-Foaming Spacer you get great a great increase in Altitude. Over the summer (once School has finished and I have more time!) we will try adding foam and post a video to see if we have the same effect :) Are you going to add foam to the boosters of the Polaron G2 or just the main stage??

[Basrockets]

Very nice onboard on that 22mm flight, so stable and so fast! Do you know why the rockets go way higher with foam? I think i'm gonna use it on my next flights as well. I am very happy that you guys tested this keep up the good work, as always ;)

[telecorpse]

AirCommandRockets Could you explain why there's so much difference?

[michaelwni]

with all these tests is there an planned project/end result?  a record of some sort in the works or just for fun?

[duroncrush]

I think this is caused by the foam expanding like the exhaust gases in a conventional combustion rocket engine. Adding a bell type nozzel might improve performance even more.

[VicVlasenko]

I guess You also could see differnces between different foams.

[MrTerrymiff]

If you used fire retardant foam and used a heat activated trigger (approx 130 C) you could put one of these every 10 or 20 meters through the scrub and have an automated bushfire suppressor. Edward de Bono eat your heart out.