What kind of water favors cavitation?

• A. Calm water
• B. Deep water
• C. Aerated water
• D. Saltwater

Answer: (C)

Cavitation happens when local pressure in the liquid drops below its vapor pressure, forming vapor-filled cavities. A key factor is the presence of nuclei that allow those cavities to form. Water that’s aerated contains dissolved air, which provides many tiny gas pockets that can act as nuclei. Under a strong pressure drop in a fast-flowing region, those microbubbles readily grow into cavitation bubbles and later collapse, causing the effects associated with cavitation. So aerated water is more prone to cavitation than water with little dissolved air. The other conditions—calm water, deeper water, or saltwater—don’t inherently supply the same number of nucleation sites, so they’re less influential than the amount of dissolved air.