Water Rocket Forum

I was imagining how it would be the speed record for a WR-car.

I know that 400 km/h is a football field per second , that is near the speed of X-12 (I think).

So adding the drag that would reduce the speed, altough a high speed is still possible.

Since is hard to find a very long non-busy road so the rocket could go from zero to zero and since launching a high-speed projectile in the ground could be dangerous I think it would be better to limit the rocket´s volume so it would run fast but not by to long.

That measure reminds of the Bugatti Veyron, its wheels allows it to stay at 400 km/h for 15 minutes...but for security the fuel tank has fuel only for 13 minutes at that speed.


It´s needless to say that any form of breaking mecanism is useless...no one has a reaction time to activate it before the rocket passes 40 meters at 200 km/h.

Conclusion:

- What is the minimal volume for a WR-car speed record ?
- What is the minimal distance accepted for a WR-car speed record ?
- How the speed record will be measured ? By a radar-speed-gun-toy ?

Razius,
Parachutes work fine out the back of a water rocket car to slow down so you are not limited by the length of road you have available. There are many options to control the release, a timer, r/c release, pressure switch to release the parachute.

Your terminal velocity is right after the air pulse burnout , so you can have a pressure switch release the chute when you sense a minium pressure in the bottle for example. This way you can build a larger capacity car but still use a short road

-todd-

thampson wrote:Razius,
Parachutes work fine out the back of a water rocket car to slow down so you are not limited by the length of road you have available. There are many options to control the release, a timer, r/c release, pressure switch to release the parachute.

Your terminal velocity is right after the air pulse burnout , so you can have a pressure switch release the chute when you sense a minium pressure in the bottle for example. This way you can build a larger capacity car but still use a short road

-todd-

You could use an electronic release and trigger it with a light beam at the end of your run. That would be a really nice way to handle drag chute deploy.

I was thinking in using a PVC pipe as a rocket vessel for a WR-car since the weight doesn´t matter.
It would be surronded by wood to avoid the shatering of a blast.

The PVC pipe advantages:

- It would make a bigger nozzle (ex.: bigger than 30mm) the problem would be to use a big O-ring system.

- It allows the use of bigger pressure without demanding extra-reinforcement.