What is cavitation?

What is cavitation?

• A. An engine failure due to fuel starvation
• B. Occurs when the prop rotates at very high speeds and a partial vacuum forms air bubbles at the tips of the prop blades
• C. A type of marine weather pattern
• D. A condition of hull corrosion

Answer: (B)

Cavitation happens when the propeller’s rotation creates areas of very low pressure on the blade, especially near the tips where the speed is greatest. If the pressure drops below the water’s vapor pressure at the current temperature, the water boils and tiny air or vapor bubbles form. These bubbles then move into regions of higher pressure and violently collapse, sending shock waves that can scour and erode the blade surfaces, causing noise, vibration, and reduced efficiency. That’s why the correct description focuses on a partial vacuum forming air bubbles at the blade tips due to very high speeds. The other options describe conditions that aren’t related to this propeller-driven phenomenon (engine fuel starvation, a marine weather pattern, or hull corrosion).

Cavitation happens when the propeller’s rotation creates areas of very low pressure on the blade, especially near the tips where the speed is greatest. If the pressure drops below the water’s vapor pressure at the current temperature, the water boils and tiny air or vapor bubbles form. These bubbles then move into regions of higher pressure and violently collapse, sending shock waves that can scour and erode the blade surfaces, causing noise, vibration, and reduced efficiency.

That’s why the correct description focuses on a partial vacuum forming air bubbles at the blade tips due to very high speeds. The other options describe conditions that aren’t related to this propeller-driven phenomenon (engine fuel starvation, a marine weather pattern, or hull corrosion).