Page 59: of Maritime Reporter Magazine (October 2013)

www.marinelink.com 59good design.Outcome of the assessmentThe hull was optimized for Þ ve differ- ent design points (different speed-draft combinations). The aft part was opti- mized for maximum propeller efÞ ciency. In addition, the bulb was lowered to be efÞ cient at lower drafts too. While this solution may result in a marginal penalty at the original design condition, the aim was to optimize the hull for a range of operating conditions. Instead of a design speed of 25 knots, the new vessels were optimized for lower speeds, with a top speed of 23 knots, following the ?slow steaming? trend observed in the last years. The overall improvement in en- ergy ef Þ ciency was 36%. ConclusionBy working closely and keeping a continuous dialogue with APL and HHI, DNV ensured that the best ideas and re- sults were combined into the Þ nal hull design. It was estimated that the opti-mized hull will result in annual fuel sav-ings of about $3 million per ship, which amounts to annual savings of $30 mil-lion for the whole ß eet. These achieve- ments provided positive market attention and ensured improved market positions for both the ship owner and the shipyard. Finally, the cost of the service provided by DNV Maritime Advisory is negligible compared with the savings achievable through improved fuel efÞ ciency. DNV, which is an independent foundation, has entrusted all commercial rights to Hyun-dai Heavy Industries.FactsDNV Maritime Advisory runs fully viscous and potential ß ow CFD simu-lations at full scale. STAR-CCM+ and Shipß ow are used on a computational cluster with more than 600 CPUs. Sev-eral design applications are used, in-cluding MaxSurf, NAPA, Rhinoceros, HDef and ShipX. DNV has been carry- ing out hydrodynamics hull optimization projects in cooperation with major ship owners, world leading shipyards and design ofÞ ces. Previous projects cov- ered several container vessels ranging from 1,600 to 14,000 TEU, Aframax and Suezmax tankers, bulk carriers ranging from 38,000 to 206,000 dwt and offshore supply vessels.Rexroth pneumatics deliver the control you need Rexroth electronic and pneumatic controls for reverse gear, controllable pitch and Voith Schneider propeller applications feature robust construction and precise control. From the marine remote propulsion control pioneer. Bosch Rexroth Corporation www.boschrexroth-us.com/marine Superior maritimecontrols performance Exactly New hull design(image courtesy DNV). MR #10 (58-65).indd 59MR #10 (58-65).indd 5910/3/2013 2:51:55 PM10/3/2013 2:51:55 PM