This blog covers the day to day progress of water rocket development by the Air Command Water Rockets team. It is also a facility for people to provide feedback and ask questions.

Saturday, August 13, 2011

G2 - Phase 2 Development

We have been continuing to do further development on the G2 rocket. This week we did a number of static tests with the G2 main stage to see what amount of thrust it will produce and what the thrust duration will be.  The rocket was connected to the load cell so we could measure the thrust accurately. We are looking for a nice long burn with this rocket and managed to get about 10.5 - 11 second long burn. :)

The full progress report is here:


Rodrigo said...

Great job George.
10 sec. of impulse is a lot, you are going to put Boosters for helping the liftoff?


George Katz said...

Thanks Rodrigo and yes the rocket is going to be fitted with three boosters, each about 10.5L in capacity fitted with a 15.6mm nozzle. When the boosters separate, the rocket should be going about 40-45 m/s. The nozzle on the main stage is just too small for the rocket to get off the ground easily by itself.

Sandy said...

Nice job George
Like rodrigo said 10 sec. Is a lot of impulse

How do you generate your foam??

George Katz said...

Thanks Sandy, we use a technique called Jet Foaming that uses a jet of water inside the rocket to mix with water in a lower section. It's very similar to how a faucet works when making bubbles in a bathtub. See here for more info:

The foam is generated during flight rather than on the launch pad.

Jamie said...

nice. will the booster nozzles be the same as on the Acceleron? are there any schematics on how those nozzles are made?

George Katz said...

Hi Jamie, yes the nozzles will be the same on the boosters as on the Acceleron V rocket. It just makes it easier as we already have the launcher components made for that size nozzle. Unfortunately we don't have a schematic for these particular nozzles, but they are essentially a tube with a flange at one end, and that's pretty much it. If you want detailed measurements I can get those for you.

Jamie said...

Detailed measurements would be really helpful. We've got a pretty big rocket but most of the thrust is wasted getting off the ground, so boosters would be a big help but i have no idea where to start on the nozzles!

George Katz said...

Jamie, where do you want me to send the nozzle details? You can email me on my regular email, and I can reply to you with the info.


These nozzles, and matching nozzle seats were machined on our lathe. Do you have access to one or someone who can make these for you?

The exact dimensions may not be appropriate for your rocket though as it depends on how much thrust you need to generate on take off, but you can scale appropriately.