Numerical Towing Tank

The Sirehna Numerical Towing Tank uses qualified computational fluid dynamics (CFD) methods to predict the hydrodynamic performance of ships, submarines, propellers and tidal turbines. It supports concept validation and hull, appendage and propulsor optimization before or alongside physical model testing.

Simulation scope

• Ship resistance: calm-water resistance, added resistance in waves, hull form and appendage optimization, self-propulsion
• Seakeeping: standard assessment, nonlinear motions and added resistance in regular waves (CFD), passive roll stabilisation tank design, active roll stabilisation (fins, rudder roll), sea state estimation and best route prediction
• Hydro-acoustics: propeller-induced noise, unsteady propeller flow behind hull, boundary layer calculation, advanced turbulence models (LES)
• Wakes and waves: near- and far-field ship wakes, turbulence effects, interaction of immersed bodies with surface waves
• Manoeuvrability: CFD tactical diameter and zigzag, stability, underwater vehicle manoeuvrability
• Cavitation: open water, tip vortex, in ship wake, ventilation
• Aerodynamics: hull optimization, aerology, exhaust and pollutant trajectories, superstructure resistance

Propeller design

Sirehna designs and optimizes propellers and thrusters of any type, including propulsive efficiency, cavitation, pressure pulses and radiated noise:

• Open, ducted and contra-rotating propellers
• Pre-swirl stators, cap fins and other energy saving devices
• Pump jets and vertical-axis propellers

Performance prediction

• Open water thrust, torque and efficiency
• Open water and behind-hull analysis (surface ship, submarine, UUV)
• Four-quadrant extension, including crash stop conditions
• Cavitation inception and extension in open water and behind hull, including ventilation