When liquid flows from a spout or through a hose, why is a series of drips also created, separate and independent of the main flow?

Question

Shouldn’t the force of the main flow inhibit these drips from forming?

In: 0

Answer 1

This is caused by something called the “boundary layer”. The fluid right at the wall isn’t moving, it’s basically stuck to the wall. That layer is very thin but it’s always there. This blunts almost all the force of the main flow when you’re very close to the wall.

This causes a very thin layer to slowly “ooze” out the end of the spout/hose without enough speed to escape with the main flow, forming drips that fall off periodically.