Investigation of the resistance and propulsion of ships, self-propelled structures and barges forms the core business of MARIN from its start in 1932 until now and is still developing. In 1932 MARIN, in those days named Netherland Ship Model Basin (NSMB), started with the Deep Water Towing Tank as the first basin to test and optimise ship hulls with their appendages and propulsors in calm water and to test the propulsive performance of many different ship types.
Through the years more and more tools became available that (partly) replaced such tests, increasing quality and scheduling of the studies. These tools range from relatively simple tools for the concept advice phase to dedicated numerical methods in the project phase. Holtrop and Mennen’s statistical performance prediction method DESP, still continuously being upgraded in-house, is a famous one. MARIN uses it for many projects in an early stage. It enables our clients to do some early predictions themselves in the pre-contract phase of a ship or they can use it with MARIN’s support for very short lead times. Later, Computation Fluid Dynamics (CFD) came up and MARIN developed her own methods like the potential flow code RAPID and the viscous flow codes PARNASSOS and ReFRESCO. Through the years, the major part of the vessels tested at MARIN changed from many well-known vessel types into the more complex knowledge-intensive ships, requiring more hydrodynamic knowledge of the flow along ship hulls and around propulsors. At the same time, optimisation work for classical ship types became faster and of higher quality with a good combination of numerical and experimental studies.
Through the years more and more tools became available that (partly) replaced such tests, increasing quality and scheduling of the studies. These tools range from relatively simple tools for the concept advice phase to dedicated numerical methods in the project phase. Holtrop and Mennen’s statistical performance prediction method DESP, still continuously being upgraded in-house, is a famous one. MARIN uses it for many projects in an early stage. It enables our clients to do some early predictions themselves in the pre-contract phase of a ship or they can use it with MARIN’s support for very short lead times. Later, Computation Fluid Dynamics (CFD) came up and MARIN developed her own methods like the potential flow code RAPID and the viscous flow codes PARNASSOS and ReFRESCO. Through the years, the major part of the vessels tested at MARIN changed from many well-known vessel types into the more complex knowledge-intensive ships, requiring more hydrodynamic knowledge of the flow along ship hulls and around propulsors. At the same time, optimisation work for classical ship types became faster and of higher quality with a good combination of numerical and experimental studies.
The development of the mentioned CFD codes resulted in a reduction of the tests per project: in more than 90% of all test projects there now is an initial CFD stage, where the hull lines are pre-optimised with RAPID before any ship model is manufactured and tested, thus drastically reducing the number of model modifications to obtain a well-optimised hull form. The well-known paint test for the alignment of appendages with the local flow is replaced now by Parnassos computations, which also provide a good insight in possible flow problems in the aftbody near the propulsors. With PARNASSOS we can also compute the nominal wake field of a single-screw ship, thus replacing the wake survey. This all has led to an appreciable reduction of cost and lead time in commercial projects, at the same time increasing our knowledge of the resistance of ships by improving our knowledge of the behaviour of the flow around a sailing ship.
Resistance and propulsion tests and computations are done for a wide range of clients: from shipyards through engineering and consultancy companies to ship owners and from governmental bodies through classification societies to ship design offices. MARIN’s focus is always on improving the product of its clientele, or solving their hydrodynamic problems.
Resistance and propulsion tests and computations are done for a wide range of clients: from shipyards through engineering and consultancy companies to ship owners and from governmental bodies through classification societies to ship design offices. MARIN’s focus is always on improving the product of its clientele, or solving their hydrodynamic problems.
Resistance and Propulsion expertise
MARIN’s resistance and propulsion expertise embodies:
MARIN’s resistance and propulsion expertise embodies:
- Understanding of the physics of hull form optimisation, necessary to be able to reduce the wave resistance.
- High quality model testing for ships with standard propulsion systems as well as ships with complex and/or hybrid propulsors, like thrusters, pods, waterjets, pumpjets, Voith-Schneiders, etc.
- In-house viscous flow codes, continuously being developed through our R&D effort, contributing to the understanding of local flow phenomena, sub-system optimisation, scale effect investigations, understanding of underlying physics of flows, free surface effects, cavitation, etc.
- Know-how on the interaction between ship hulls and propulsors and/or rudders.
- A large database with full scale speed trials results from ship models tested at MARIN; this database helps us to determine the required trial allowance for new ships with a high accuracy.
Specific MARIN areas of resistance and propulsion expertise are:
Specific resistance and propulsion tools at use in MARIN are:
- Statistical performance prediction programs
- DESP
- Potential flow codes
- RAPID
- RAPID Explorer for systematic hull form variations
- Viscous flow codes
- PARNASSOS
- PARNASSOS Explorer for systems hull form variations
- ReFRESCO
- CFX/Ansys
Contact
Phone +31 317 49 34 72
E-mail powering@marin.nl
The Resistance and Propulsion Team is headed by:
Phone +31 317 49 34 72
E-mail powering@marin.nl
The Resistance and Propulsion Team is headed by:
ir. Jaap AllemaResistance and Propulsion Knowledge Coordinator