On the b3ta boards this was titled "Look what Mum's getting for Christmas!" It would be a nice little experiment to explain how steam power works to the kids. http://www.b3ta.com/links/Look_what_mums_getting_for_Christmas
On the b3ta boards this was titled "Look what Mum's getting for Christmas!" It would be a nice little experiment to explain how steam power works to the kids. http://www.b3ta.com/links/Look_what_mums_getting_for_Christmas
Comments (26)
The water is raised to boiling at which point it flashes to steam and ejects a spurt of water down the pipe and out. This provides the impulse to drive the machine forwards. Because of inertia the water always overshoots a bit and is then sucked back into the heated area, rapidly cooling it so the steam condenses and we're back to the beginning of the cycle again.
At first sight it may appear that this will produce no net thrust but since the jet being expelled tends to go all in one direction wheras the water being sucked back in will tend to come from all around the inlet there's an imbalance leading to an overall thrust.
Provided you can arrange a way to fill then chamber these motors will run fine on just one tube.
Simple motors can have just a coil of tube as the heating chamber, posher examples have a diaphragm over the top which pops up (like a food jar lid) with each expansion and flexes down again after. This makes the motor run better and provides a satisfying pop-pop noise. The coiled tube sort are nearly silent.
Ah, too true. Of course, pools and indoor bathtubs don't count! ;)