SHIP DESIGN OPTIMISATION

Performance analysis and design optimisation for commercial ships, service operation vessels & work boats

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 commercial cargo ships, service operation vessels, cruise ships, work boats , fully foiling and foil assisted high speed vessels, advanced and unconventional vessels, to improve performance, comfort and safety, increase energy efficiency, and to save fuel and reduce emissions.

Our specialist CFD technology and expertise is at the forefront of new design solutions to enhance energy efficiency in the shipping industry.

Using CFD Technology

We use advanced visualisation techniques to understand the flow features and to share that knowledge with clients. We post-process the simulations in a way that the designers obtain load cases and internal forces and moments for dimensioning the appendages of their designs. We carry out Fluid Structure interaction for appendages and sails. We assess cavitation in the appendages of all high speed craft. We have developed foil section optimisation loops that take into account transition and cavitation. For extensive design campaigns we optimise hull and appendage shapes using modern optimisation techniques like neural networks response surface models and optimisation algorithms.

Our CFD methods cover a large variety of flow behaviours and includes free-surface flow, viscous flow, full-scale performance prediction, fluid-structure-interaction and dynamic behaviour. We excel in what we do, in our engineering expertise, our passion to succeed, our attention to detail and our exclusive use of the best tools available. Our powerful resources are a guarantee for outstanding results delivered to support your project.

CFD technology is a huge benefit for naval architects when optimising any vessel. Historically, designers have used more traditional technology, such as towing tank tests for their final designs to make sure they meet their clients’ requirements. But the force similarities between the model at scale and the real ship cannot be achieved in a towing tank, which makes testing complex, based on assumptions and empirical formulations.

Using our CFD technology eliminates this problem, since it models the vessel at full size, and captures the stern wake and boundary layer effects directly at full size. Other advantages of CFD compared to tank testing is that realistic moments of inertia and VCG are easily achievable in simulations as well as the decomposition of forces and moments by components like hull and appendages, and by physical origin like friction and pressure. Moreover, CFD offers a greater insight into the details of the flow through images, video animations or interactive visualisation files. Even virtual and augmented reality is starting to make an impact today. CFD also offers substantial reductions in time and costs compared to physical models.

A good design process involves investigating the hull with its appendages and propellers simultaneously, as there is no isolated engineering component without an effect on the whole system. CFD allows us to perform calculations on the system as a whole, so the design process can be steered for fuel efficiency, comfort and safety.

CFD technology can also be used for aerodynamic simulations to capture wind effects around exhaust vents in order to investigate where the smoke will travel for passenger comfort.

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
  • Global  ship bending moments in waves
  • Damage stability and ship launching, life boat launching
  • 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)

 

* Engine room and cargo hold and cabin ventilation

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

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 motion velocities, accelerations and trajectories of the body
  • 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

Ship Decarbonisation & Energy Efficiency Performance (EEXI)

To help reduce emissions, we assist shipping companies with our specialist CFD technologies to investigate carbon-free energy alternatives and design solutions. We also specialise in EEXI/EEDI calculations based on high-fidelity RANS CFD and offer EEXI/EEDI calculations in a very efficient and cost effective manner, having developed validated workflows and Best Practice Guidelines in conjunction with a leading classification society (Lloyds Register) by testing potential solutions for vessels.

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Innovative simulation for Wind Assisted Ship Propulsion (WASP)

To address the global challenge of reducing emissions for commercial shipping, shipping companies are look for carbon-free alternatives by testing potential solutions for vessels, and the introduction of WPT (Wind Propulsion Technology) has been evaluated. According to recent studies, wind-assisted ship propulsion using rigid wings, sails, kites, Magnus rotors or other novel devices on some specific vessel types such as bulk carriers and tankers, have the potential of fuel savings and emission reductions around 10-30%. Due to our renowned experience and specialist technology, we are able to offer a holistic analysis of the benefits of WPT.

Cape Horn Engineering has developed a simulation workflow to directly compare the efficiency of wind assisted ship propulsion (WASP) devices. The simulations take into account the most important effects of adding the wings, Flettner rotors or any other type of wind powered device to the vessel. Both the water flow experienced by the hull at a given vessel speed and the air flow experienced by the hull top sides, superstructure and WASP devices, at a certain wind speed and direction, are modelled simultaneously in a single simulation.

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Simulations

High-fidelity CFD with rotating propellers

Simulated constant RPM propeller performance, including roll stabilisers and superstructure windage, to assess vessel speed and shaft power on the award-winning Najiba.

Versatile hydrodynamic analysis

Examples include resistance, propulsion, seakeeping, slamming, and exhaust dispersion simulations for a range of motor yachts and commercial ships.

Realistic 4DOF motion simulation

Simulated yacht motion in 2.5m waves at 30° from stern. Captured realistic surging effects, with speed fluctuating ±7 knots around an average of 9.6 knots.

Integrated air & water flow simulation

Developed a workflow to evaluate Flettner rotors, wings, and other WASP devices by simulating hull-water and superstructure-air interaction simultaneously.

Innovative low-emission sail design

Simulation and analysis of rigid sail systems designed to cut emissions in commercial shipping — a new approach to auxiliary wind power.

50 m Superyacht Turning Circle

6‑DOF simulation of a superyacht’s ITTC turning circle with active rudders and stabilisers.