UBC Theses and Dissertations
Parabolization and structural integrity of side bulb applied platform supply vessel hull form Deli, Ozgur
The parabolization work is a hull-optimization method for minimizing total resistance of ship by using numerical and experimental methods. Ship total hydrodynamic resistance is a sum of frictional resistance, form resistance and wave resistance. The form resistance is a fraction of frictional resistance while the wave resistance dominates as speed increases. It becomes clear to turn toward minimizing wave resistance for hull-form optimization studies regarding increased speeds. In 2002, Calisal et al. reported a 10% decrease in effective horse power at Fn = 0.275 for a coaster tanker. The objective was to attain a beneficial wave-resistance reduction over a moderate to relatively high operating speed range. The parabolization work was done by a computer software that expends the form at waterline and replaces the conventional parallel middle-body section with parabolic side bulbs. This study was made for a oil platform supply vessel (PSV)and studies an improved , new hull form. The form is a new “retrofit” , for the present parent hull form, increasing the vessel’s beam up to 5% and its displacement accordingly. In this thesis new scantling was calculated for the parabolized hull. The structural analysis and design for the parent and “retrofit” hull forms were done, using the rules and guidelines of the American Bureau of Shipping (ABS). The final part of the thesis provides a cost payback analysis of the parabolized PSV. A fuel savings of 280,000 liters/year provides $235,000.00 per year saving based on a 5.88% drop in resistance . The investment for the construction of an amidships bulb is estimated at $161,000. The payback period for the construction of an amidships bulb is estimated to be nine to seventeen months, with different ship type factors. In addition resistance reduction saves 753,900 kg of CO2 and 134,100 kg of NOx . The parabolization cost analysis is seen in three parts. First, the investment cost of the side bulb. Second, the savings in fuel cost representing the savings in the running cost and the change in the investment cost of propulsion machinery of the vessel and thirdly, the environmental savings by low CO2 and NOx emission.
Item Citations and Data
Attribution-NonCommercial-NoDerivs 2.5 Canada