Use of CFD in the optimisation of a naval ship

In recent years there has been a change in the operational requirements for large Naval Support Ship vessels. Whether responding quickly to military conflict or contributing to an expeditionary force, there has been a demand for vessels to have both higher sustained cruising and sprint speeds, typically in excess of 18 knots cruise and 20+ knots sprint. In parallel the through life cost of operation must also be considered and improvements in hull efficiency, reduced fuel consumption, can significantly reduce the through cost of operation to the customer.
In response to these changing requirements BAE SYSTEMS Surface Fleet Solutions (SFS), in conjunction with MARIN, developed a 25000 tonne Naval Support Ship (NSS) capable of achieving the required speeds, whilst maintaining extensive blue water and manoeuvring capabilities. These speeds can be achieved using various propulsion configurations depending on customer requirements. The NSS was developed utilising BAE SYSTEMS SFS proven design and construction experience of these vessel types. This design experience is combined with MARIN’s extensive state of the art CFD design methods to produce a fully optimised hydrodynamic hull form. The extensive CFD programme enabled multi-objective optimisation prior to model testing, examining areas such as bulbous bow and transom flow. This allowed the design to be significantly matured prior to testing and the test results further demonstrate the ability of CFD tools to operate as part of today’s ship design process. The paper will demonstrate how current methods are applied before illustrating the benefits that CFD can bring to the ship design process. Finally some foresight will be provided into possible future developments of CFD in ship design.