Cavitation
How does cavitation differ from boiling?
Boiling occurs due to temperature rise at constant pressure, while cavitation is caused by pressure drop at nearly constant temperature, leading to transient vapor bubble formation and collapse.
What pressure condition triggers cavitation?
Cavitation occurs when local static pressure is less than or equal to the saturated vapor pressure of the fluid at the given temperature.
What are the shock wave pressures generated during bubble collapse?
Microjet formation and collapse can generate shock waves exceeding 10,000 bar, causing extreme pitting and erosion.
Cavitation is the formation of vapor-filled cavities in a liquid when local static pressure drops below the liquid's vapor pressure at the operating temperature, followed by violent collapse upon pressure recovery, generating shock waves that cause severe material damage.
In manufacturing and maintenance, cavitation is monitored as a critical failure mode in centrifugal pumps, control valves, and hydraulic systems. It is detected via high-frequency noise (10–100 kHz), vibration analysis, and impeller pitting. Adjustments like increasing suction pressure, reducing fluid temperature, or re-engineering inlet geometry are made to maintain pressure above vapor pressure, preventing damage and ensuring equipment reliability.
Impeller pitting and erosion from repeated bubble implosions remove material, reducing hydraulic efficiency and causing premature failure.
Shaft and bearing damage due to cavitation-induced vibration accelerates wear and risks catastrophic breakdown.
Operational missteps such as installing pumps with insufficient suction head, using starved inlet configurations, or operating fluids at excessive temperatures without pressure compensation.