Maritime Vessel Hydrodynamic Suction & Interaction Simulator

Analyze Bernoulli pressure drop, squat, yawing moments, and collision danger when ultra-large cargo vessels pass small craft in restricted channels.

Test Scenarios:

Hydrodynamic Pressure Field & Vector Forces

High Pressure (Bow Push) Low Pressure (Suction Trough) Venturi Suction Streamline
Tip: Click or drag the small vessel on screen to examine local suction gradients
Longitudinal Scrub: -50 m
Lateral Suction Force
18.4kN
Inward Attraction (Amidships)
Yawing Moment (Torque)
-42.6kN·m
Stern Pull (Inward Sheer)
Required Counter-Rudder
28°Port
Near Rudder Stall Limit
Tipping / Capsize Risk
88%
CRITICAL HAZARD
DANGER: Small craft trapped in amidships Bernouilli suction trough with severe port yawing moment! ALRT-HYDRO-9

Bernoulli Suction & Venturi Trough

As a massive vessel displaces hundreds of thousands of tonnes of water, restricted flow between the hulls accelerates return currents. According to Bernoulli's principle, water speed increase causes an immediate hydrostatic pressure drop, pulling nearby craft bodily into the side of the ship.

ΔP = -½ ρ (V_channel² - V_inf²)

Violent Yawing Moments

The danger is rarely pure lateral drift: when a small craft is near the bow, positive pressure kicks the bow out and stern in. As it moves amidships or near the propeller suction zone, the stern is violently sucked inward, sheering the small craft across the cargo ship's bulbous bow or hull.

N_yaw = C_n · ½ ρ L² T V² (h/T)^(-k)

COLREGS Rule 9 & Safe Margins

Navigating in narrow straits (like the Singapore or Malacca Straits) requires maintaining a minimum lateral separation of at least 2.5× the large ship's beam (typically >110m). Reducing large vessel transit speed by even 3 knots cuts interaction suction by over 40%.

Clearance_safe ≥ 2.5 · Beam_Large
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