Algodoo

Launches automatically. The red box is scripted to spawn water on collision... It's restitution is set all the way up so it continuously bounces in the tight space, endlessly producing water and causing thrust... The water is set to "vaporize" in 0.25 seconds.

Scripts used:

Water Spawning: Type in "OnCollide"- scene.addWater({vecs = [e.pos, e.pos, e.pos]})


Water Vaporize Time: Type in text box at the top of script menu- SPH.vaporizeTime = 0.25