Water hammer can work in both directions, and I only discussed one of those in the previous video (https://youtu.be/xoLmVFAFjn4). This episode revisits that demonstration to show how water hammer can form a vacuum pressure in a pipe. Momentum carrying fluid away from a valve wants to keep going even after the valve is closed. This generates a negative pressure than can cause major damage!
This video shows the basics of fluid cavitation, including demonstration from AvE. If you subject a fluid to a sudden change in pressure, some interesting things can happen. You can cause tremendous damage to moving parts, or you can harness this destructive power in many beneficial ways.
