Hull Form Optimization for a 62000DWT Heavy Lift Multi-Purpose Vessel

Abstract

Abstract A new optimized hull form was proceeded based on a parent ship 60000 DWT bulk carrier. The goal of optimization is to obtain better resistance performance in the loading conditions of scantling draught and design draught. Firstly, the numerical simulation of the parent ship was carried out, the flow field information around the hull was analyzed, the area of high or low pressure was checked, and the area was optimized to make the pressure distribution more uniform. At the same time, the bow entrance section was optimized to reduce the wave-making resistance, and the length of the run body was lengthened to reduce the flow separation area and the viscous pressure resistance. Aiming at these above optimization objectives, the deformation range of hull form was set by commercial software CAESES, and the total resistance of generated optimized cases was solved by SHIPFLOW and evaluated by STARCCM+ software. To grantee the resistance reduction at both design draught and scantling draught, by using the operation profile optimization method, the resistance weights of scantling draught and design draught were set as 50% respectively, that is, the total resistance of optimized hull form equals 50% resistance of design draught condition and 50% resistance of scantling draught condition. The optimization results of total resistance were compared and analyzed, and the cases with relatively minimum total resistance were obtained. On this basis, the wake field at the propeller disk was optimized either, and finally, the target optimization of hull form was obtained. The numerical results showed that, compared with the parent ship, the total resistance at the design speed of the design draught was reduced by about 1.64%, about 2.10% at the design speed of the scantling draught. The wake distribution on the propeller area was more uniform. The final optimized hull form meets the target requirements.