Advanced Lab Project Year II - Water Flowing From Two Holes

Consider a tall tank of water with two small circular holes at the bottom. The two jets leaving the tank may combine to form one or flow out separately. Single and twin jet phases can both be seen, for a given set of holes, by changing the hydrostatic pressure at the bottom of the tank. At low pressure, the jets flow out at low velocity and the forces of surface tension combine them into one. At high pressures the outflow velocity is high and the jets do not combine. Below you can see the phase transition !

We experimentally studied the phase transition, finding that the two states occure due to a competition between surface tension and inertia. We investigated how the split of the combine jets is affected by five key parameters. If you would like to know more you can read our report.