DNV GL Looks into Hull and Propeller Performance
International certification society DNV GL is launching an advanced hull and propeller performance analytics module as part of the new fleet performance management service ECO Insight.
According to DNV GL, the module is based on computational fluid dynamics (CFD) methods to correct for changing operational conditions and produces much more accurate results than existing approximate or experimental methods.
As explained, tracking hull and propeller degradation is a challenge that has not yet found an adequate solution. Experts suggest that, as a result of hull fouling, the world fleet could be sailing with approximately 30 per cent added resistance and consequently significantly higher levels of fuel consumption. Undertaking hull and propeller cleaning on a more regular basis is already recognized as improvement lever by many shipping companies. However, the question of when and how the procedure should be carried out has not yet been addressed systematically.
Hull and propeller performance computations show how much resistance is added over time due to fouling, by analysing the gap between the theoretical and measured power demand of a vessel, after correcting for influences like speed, draft, trim, weather and other operating conditions.
“We use data that shipping companies are already collecting,” Dr Torsten Büssow, DNV GL’s Head of Fleet Performance Management, explains. “Our CFD capabilities, which we also use in our lines optimisation, retrofit and trim assistant services, allow us to very accurately normalize vessel specific power demand under each reported condition.”