Over the years, we have acquired a large number of tools, specifically for the design and analysis of the performance of ships and yachts. Besides those that are commercially available, we have always invested in developing our own tools for specific purposes, using our own experience and capabilities.
  • Velocity Prediction Program for Sailing Yachts (YachtVPP)
    For many years we have been working on the development of our own VPP. This is a mathematical program to predict the performance of sailing yachts. We were one of the first to incorporate equations for the horizontal moment equilibrium, to find exact values for the rudder angle.
    Read more..

  • Dynamic Velocity Prediction Program for Sailing Yachts (DYachtVPP)
    Like the 'normal' VPP, this software program is able to predict the performance of sailing yachts, however, this model predicts the dynamic behaviour during tacking and gybing of the yacht, using various rudder control models to accurately find the optimum way to manoeuvre.
    Read more..

  • Performance Prediction for Powered Ships and Yachts (YachtPower)
    Using our experience from numerous tank tests, combined with available analytical and statistical methods, this program predicts the resistance and all of its components of the hull and the appendages, ranging from tugs and trawlers to very fast planing motor yachts. Together with a propeller optimization routine, accurate prediction of speed, power and range can be made.
    Read more..

  • Concept Exploration Model for Sailing Yachts (CEM)
    The CEM is a mathematical model used in the early stages of design. Exploring the boundaries of the available design space, it finds the optimal design, depending on a wide range of criteria such as performance, interior space, building cost and safety.
    Read more..
Computational Fluid Dynamics is now approaching maturity. So-called RANSE (Reynolds Averaged Navier-Stokes Equations) codes, with a free-surface capability, are now able to not only rank various ship design options correctly, but also come close to predicting the flow and flow-generated forces and pressure fields in an absolute sense correctly.

At Van Oossanen & Associates b.v. we use the FINE/Marine CFD system, consisting of the Numeca Hexpress automated unstructured grid generation software and the ISIS-CFD RANSE solver developed by Ecole Centrale de Nantes (ECN).
For the detailed strength and stiffness analysis of parts of the hull, superstructure, appendages or rigs we use Multiframe, developed by Formation Design Systems.

For the detailed strength and stiffness analaysis of the complete hull with or without superstructure we use FEMAP developed by UGS.
  • CAD/CAM
    We use a range of CAD systems, depending on the purpose:
    - For advanced 3-D modelling, we use the MaxSurf-suite developed by Formation Design Systems for the hull, appendages and other complicated double-curved shapes and surfaces.
    - Rhinoceros is used for the detailed modelling of construction, interior and systems.
    - Steel and aluminum constructions and plate nesting and cutting, are modelled in 3-D using ShipConstructor.
    - For the traditional 2-D drawings, AutoCAD is used.

  • Seakeeping
    A so-called strip theory program, Seakeeper, which is part of the Maxsurf range is available for the calculation of the six components of motion, accelerations, relative motion, force and moment loading, etc, in regular or irregular waves. For non-slender, streamlined floating bodies, for which strip theory is not suitable, we have access to a computer program utilizing diffraction theory, with and without forward speed.

  • Intact and Damaged Transverse and Longitudinal Stability
    Hydromax is available for the assessment of transverse and longitudinal stability of all types of ships, yachts and advanced marine vehicles. We have access to programs for the analysis of extreme situations in connection with addressing the problem of ultimate stability, including effects of wind and waves (for the determination of the likelihood of broaching and capsizing), the stability lost or gained due to forward speed and associated dynamic effects, etc.

  • Structural Design
    Various programs are available for structural design and analysis. Steel, aluminium, GRP and fibre-reinforced composite structures can be addressed. We commonly use programs based on Lloyds Register, and other Classification Society Rules. We also utilize the scantling assessment according to ISO 12215 for pleasure craft with a length less than 24 m, for which we use the Wolfson Unit's program HullScant.

  • Vibration and Noise
    We have access to programs for the analysis of both mechanical and hydrodynamic-excited noise in ships, yachts and advanced marine vehicles, including the assessment of cavitation on propulsors and appendages and the subsequent vibration and noise caused thereby.