‘VIRTUE’ numerical towing tank takes form
Under the European Commission’s Sixth Framework Programme, a group of CFD specialists and service providers, led by HSVA, have joined forces to develop a new IT platform for the design of fully hydrodynamically optimised ship hulls.
Numerical simulation of fluid flow around ships and marine structures has a long tradition in naval architecture, dating back to the 19th century. Today, Computational Fluid Dynamics (CFD) is an increasingly important tool for analysing flows around ships and propulsors. CFD methods provide important insights into physical flow characteristics and hence can provide the background for design integration.
“Advances in computer technologies over the past two decades have brought the dream of a complete numerical towing tank or ‘virtual basin’ within reach,” says Jochen Marzi of HSVA. “Today’s methods do however lack the accuracy to match results obtained in real-life experiments. The combination of improved accuracy and integrated design optimisation is the key to future ship design.
“The goal of the VIRTUE Integrated Project (‘Virtual tank utility in Europe’) is to develop new and to improve existing software to deliver a complete toolset for marine hydrodynamics. This includes resistance, propulsion, seakeeping, manoeuvring and cavitation prediction,” explains Marzi. “All of these elements will be integrated in an IT platform aimed at delivering fully hydrodynamically optimised ship hulls, using multi-criteria, multi-objective optimisation.”
Enhanced and more competitive services
VIRTUE constitutes an EU-wide initiative of leading marine CFD players. Its end result, a fully operational virtual basin, will complement model testing in real basins and hence substantially improve the provision of services to the marine industry and support the development of innovative techniques and concepts.
“It will also help strengthen the competitiveness of the EU shipbuilding and shipping industries,” says Marzi, “promoting European co-operation and helping SMEs get involved in leading edge research.”
VIRTUE's scientific and technological objectives include:
- Improved hydrodynamic testing through new and better CFD tools;
- Improved existing CFD tools, in terms of performance and accuracy;
- An integrated design environment for complete modelling and simulation of ship behaviour at sea, combining proven numerical and CFD tools and techniques;
- A smooth and versatile communication and data exchange system for linking marine CFD service providers, such as model basins, and end users.
Shaping the future of maritime CFD
Marzi says all project activities are progressing according to schedule. “Our team has carefully shaped a work plan to meet the requirements of improved computational accuracy and speed and integration of future CFD analysis tools. The work performed in the project will deliver better and more accurate CFD results, closing the ‘quality gap’ between today’s CFD and experimental analysis. Our work will also influence production costs, mainly by providing reliable data for the evaluation of new designs in affordable time.”
VIRTUE is set to run through 2008. During the project, a number of demonstration prototypes will be developed and made available to the wider public. Initially encompassing simpler (e.g. potential flow) methods, the virtual basin will eventually include more refined, ‘RANSE’-based CFD prediction methods, delivering a holistic analysis of hydrodynamic behaviour. Marzi says initial concepts for the use and application of the virtual basin and results obtained will be presented in the near future.