Marine Propeller Cavitation

Marine Engineering

How It Works

Marine propeller cavitation occurs when high rotational blade velocity accelerates flow across the suction face, causing local static pressure to drop below the saturated vapor pressure of seawater (p_v). The water locally vaporizes into micro-cavitation bubbles. When these vapor bubbles are swept downstream into higher-pressure regions, they implode violently within microseconds, generating localized micro-jets and shockwaves exceeding 1 GPa that cause severe structural blade pitting and acoustic noise.

Governing Equation
σ = (p_ambient - p_vapor) / ((1/2) · ρ · V_rel²) , p_min < p_v ⇒ Cavitation