DNV GL module analyzes hull and propeller performance

MARCH 18, 2015—Fuel efficiency remains a key concern for shipping, but 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. Until now, however, the question of when and how the procedure should be carried out has not yet been addressed systematically.

Classification society DNV GL is launching an advanced hull and propeller performance analytics module as part of its new fleet performance management service, ECO Insight. 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.Hull and propeller performance computations show how much resistance is added over time due to fouling, by analyzing 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.” The hull and propeller degradation computation is offered as part of DNV GL’s new fleet performance management service ECO Insight.

The ECO Insight service provides a comprehensive and easily accessible way to manage the performance of a fleet, including voyage, hull & propeller, engine & systems performance. It supplements customers’ own fleet reports with industry data, such as Automatic Identification System (AIS), weather, or fuel, and provides unique benchmarking capabilities. Advanced engineering systems are also packaged into the portal. Navigator Insight is the preferred recording tool used for the ECO Insight service. This data collection and logging software ensures high quality data collection on board by carrying out smart plausibility checks against specific vessel particulars.