Design Optimisation and Performance CFD Analysis for Superyachts
Cape Horn Engineering have pioneered RANSE based CFD since its very beginning and continues its research work on a daily basis. Due to our proven expertise in the America’s Cup, Volvo Ocean Racing and other high profile sporting events, we can apply this cutting edge technology to a wide variety of other marine applications including superyachts, sailing yachts and motor yachts, fully foiling and foil assisted high speed vessels, to improve performance, comfort and safety, increase energy efficiency, and to save fuel and reduce emissions.
What is CFD analysis for superyachts?
Superyacht design optimisation CFD is the use of Computational Fluid Dynamics, specifically full scale RANSE (Reynolds Averaged Navier Stokes Equations) simulations, to analyse and refine every hydrodynamic and aerodynamic aspect of a superyacht before a hull is ever built. For motor and sailing superyachts, explorer yachts, and foiling high speed vessels, Cape Horn Engineering models the complete vessel at real size with realistic inertias, all appendages, propellers, superstructure, and sea state, so designers and owners get reliable predictions of performance, comfort, safety, fuel consumption, and emissions.
Cape Horn Engineering has pioneered RANSE based CFD from its earliest days and continues that research work daily, applying the same cutting edge methods proven in the America’s Cup and Volvo Ocean Racing to superyacht projects of every size and rig.
- Who we serve: superyacht designers, naval architects, owners, and build teams working on motor superyachts, sailing superyachts, explorer yachts, and foiling or foil assisted high speed vessels.
- What we deliver: full scale RANSE CFD for resistance, propulsion, seakeeping, manoeuvring, roll damping, FSI, cavitation, EEDI, and aerodynamic comfort, with load cases, forces, and moments ready for structural dimensioning.
- Proof points: CFD analysis of the award winning 58m sailing superyacht Najiba with Philippe Briand and Vitruvius Yachts, the Conrad C-140 sailing superyacht with Frank Neubelt and German Yacht Couture Project Agency, the 50m Explorer Yacht with Humphreys Yacht Design, the Baltic 112 Liara and the Windy SLR 60 with Malcolm McKeon, the Fleming 85 with Norman R Wright and Sons, and a 47m Perini Navi superyacht.
- Typical outcome: realistic fuel savings of at least 5 percent, reduced emissions, improved seaworthiness, better onboard comfort, and safer operating limits.
This heritage of offshore racing research is what lets Cape Horn Engineering apply the same level of rigour to a cruising superyacht, an explorer yacht, or a fully foiling high speed craft, improving performance, comfort, safety, and energy efficiency, and helping reduce fuel use and emissions across the fleet.
Using CFD Technology
Our superyacht design optimisation CFD capabilities
- Advanced flow visualisation and post processing, so designers receive load cases and internal forces and moments ready for dimensioning appendages and structure.
- Fluid Structure Interaction (FSI) for appendages and sails on sailing superyachts.
- Cavitation assessment on propellers, hydrofoils, and the appendages of high speed craft.
- Foil section optimisation loops that account for transition and cavitation.
- Hull and appendage shape optimisation using neural network response surface models and modern optimisation algorithms for extensive design campaigns.
- Holistic modelling of the hull, appendages, and propellers together, so the whole system can be steered for fuel efficiency, comfort, and safety.
- Aerodynamic simulations around funnels and exhaust vents to predict where smoke travels, protecting guest and crew comfort on deck.
Why full scale CFD changes the superyacht design process
Towing tank tests have long been the traditional reference for naval architects. The force similarities between a scaled model and a real superyacht cannot be fully achieved in a tank, which makes results dependent on assumptions and empirical corrections.
Cape Horn Engineering’s CFD technology removes that limitation by modelling the vessel at full size, capturing the stern wake and boundary layer effects directly at full scale. Realistic moments of inertia and center of gravity are easy to set, forces and moments can be decomposed by component (hull, each appendage) and by physical origin (friction, pressure), and the flow can be explored through images, video animations, interactive visualisation files, and virtual or augmented reality. The result is a faster, cheaper, and deeper design loop than physical models alone can offer.
Because CFD models the entire vessel as one system, the design process can be steered simultaneously for fuel efficiency, comfort, and safety, and the same tools also handle windage around the superstructure, exhaust gas dispersion, and helicopter deck airflow for SHOL studies.
Advantages of CFD compared to tank testing
- All simulations are at full scale
- Simulations use realistic inertias and centres of gravity (something not feasible in tank testing)
- Oblique incident waves coming from any direction can be simulated, tank testing is usually limited to head waves
- Decomposition of individual forces and moments for the hull and each appendage
- Precise analysis of vessel motions, velocities, accelerations
- Flow visualisation and animation to gain insight and understanding about differences between designs
- Simulations are 100% reproducible
- Hull or appendage shapes can be easily changed without building new models
- It is easy to test many design configurations i.e. to swap appendages Easily test in a variety of sailing conditions (speed, wave characteristics) to compare performance
- Time and cost reduction
Areas where we can help...
- Hull and appendages performance and optimisation
- Propulsion, propeller selection, fuel consumption, delivered power
- Cavitation on propellers and Energy Saving Devices (ESD)
- Energy Efficiency Design Index (EEDI)
- Manoeuvres according to ITTC procedures
- Appendage torque and bending moments, load cases
- Seakeeping, added resistance, motions and accelerations
- Slamming loads, water on deck, sloshing
- Roll damping, performance of fin stabilisers, trim tabs and interceptors
- Fully foiling and foil assisted vessels
- Cavitation on hydrofoils and 2D foil section optimisation
- Fluid Structure Interaction (FSI) of appendages
- Occupant safety and comfort including local wind effects and exhaust gas
- Windage and structural wind loads on superstructures Ship Helicopter Operating Limits (SHOL)
- Global ship bending moments in waves
- Damage stability and ship launching, life boat launching
Benefits of using CFD technology
- Improved propulsion
- Improved fuel efficiency – fuel savings of at least 5% are realistic
- Reduced emissions
- CFD investigation can reduce the safety margin to avoid over-powering your vessel
- Improved seaworthiness
- Improved comfort
Case Studies
See our case studies on Superyacht Design Optimisation
Simulations
Self-propulsion CFD simulation for the award-winning superyacht Najiba (Philippe Briand – Vitruvius Yachts). The simulation features rotating propellers at a constant RPM and delivers the attained vessel speed and shaft power. All appendages including roll stabiliser fins as well as the details of the superstructure to capture the windage are modelled.
This film presents the C-130 sailing superyacht, designed by German yacht designer Frank Neubelt with German Yacht Couture Project Agency, after extensive R&D that included 117 CFD simulations by Cape Horn Engineering to optimise comfort and performance, with results used in North Sails’ Velocity Prediction Program.
Roll decay tests used simulations to measure how yacht appendages reduce rolling.
The full-size yacht, fitted with different parts, started heeled at 10° with no speed, was released, and its free rolling was recorded. Damping values were then calculated from the motion.
Seakeeping accelerations for the Windy SLR60 with Malcolm McKeon Yacht Design.
CFD analysis of the influence of side wind on the hydrodynamic centre of lateral resistance for the award-winning superyacht Najiba (Philippe Briand – Vitruvius Yachts). Combined hydrodynamic/aerodynamic simulation. Comfort on deck evaluated at the same time.
Examples of CFD simulations carried out for motor yachts and commercial ships. Resistance, propulsion, seakeeping, slamming, exhaust gas on deck.
Demonstration for a 4 Degrees-of-Freedom simulation, with freedom for the yacht to move naturally though the waves. The open-water propulsion is based on the yacht propeller. The propeller torque is kept constant, and thrust and delivered power are variable.
Turning circle manoeuvre of a 50m superyacht following the ITTC recommended procedure for full scale manoeuvre trials. 6 DOF simulation with active rudders and fin stabilisers.
Cape Horn Engineering were proudly commissioned for their technical expertise to evaluate the sailing performance for 3 candidate keel configurations on the E-volution and Classic 47 metre cruising sloop.
Our Sail Design Service
Our online CFD computations are for sail makers, naval architects and yacht designers.
State of the art aerodynamic technology and high fidelity simulations to optimise your sail design and increase sailing performance.
We will analyse and evaluate the performance of your sails (and the boat), from a single sail design to multiple geometries, weather conditions and racecourse conditions. Accurate results of the best possible sail geometry plus an efficient visualisation of the sail loads will be available in just a matter of hours.
