Marine Propeller Cavitation Calculator
Propulsion hydrodynamics: Evaluate Keller minimum blade area ratio, Burrill blade loading limit, local cavitation number, and thrust breakdown risk.
Propeller & Operating Parameters
Cavitation Margin & Blade Loading
Recommended Tools & Equipment
Tested hardware and components for high reliability
Frequently Asked Questions
Why does propeller cavitation cause severe physical damage to bronze blades?
When local pressure drops below water vapor pressure (~1.7 kPa at 15°C), vapor cavities (bubbles) form on the blade suction back. As these bubbles sweep into regions of higher pressure towards the trailing edge, they collapse asymmetrically. The implosion shoots microscopic liquid micro-jets at velocities exceeding 1,000 m/s with local impact pressures of hundreds of megapascals, rapidly eroding and pitting nickel-aluminum bronze (NAB).
How does Keller's formula prevent propeller cavitation?
Keller's empirical formula establishes the minimum Expanded Area Ratio (EAR = A_E / A_0) needed to distribute delivered thrust over sufficient blade area. By keeping the average hydrodynamic pressure reduction on the blade back within safe limits relative to static water head (p0 - pv), it prevents widespread sheet cavitation.
What is thrust breakdown in heavily cavitating propellers?
When cavitation sheets cover more than 20–30% of the blade suction back, the low pressure on the suction side cannot drop any further (clamped at vapor pressure p_vap). As rpm increases, additional thrust cannot be generated on the suction side while blade drag surges. Propeller efficiency plummets drastically, a condition known as cavitation thrust breakdown.