“Reaction engine” experiment
How to make a reaction engine with a jar and alcohol
How can we make a reaction engine? We’ll only need a glass jar with a lid, ethyl alcohol and a little ingenuity!
Observe safety rules when working with fire.
Warning! Only under adults supervision.
Reagents and equipment:
- glass jar;
- lid with hole;
- 96% alcohol (50 ml).
We pour alcohol into the glass jar and seal it with a lid with a hole in the center with even edges. The jar is shaken so the alcohol evaporates better. We ignite the alcohol fumes by the hole. The engine starts to roar!
It’s easy to make a simple impulse reaction engine from an ordinary jar. Alcohol will be the fuel. But the secret of this engine is the lid with the hole! The proportions of the hole need to be chosen precisely for each container: if we make it bigger, the fuel will run out quickly, but if we make it smaller, the flame will go out from a lack of oxygen. if the geometry of the hole and the size of the container is correct, the fuel will burn in pulses. With each pulse, it spits out a tongue of flame, and then sucks the air through the hole into the region of expansion that suddenly appears, receiving a new portion of oxidizer. The engine will function until the fuel runs out or the jar cracks from overheating.