Optimization of ship hull form for moderate sea state

Abstract

The challenge of international market and the search of increasing performances lead the process of ship design to a continuous enhancement in merchant field where the dedicated time for a thorough design is ever decreasing. While improving the performance of hull form, seakeeping is a crucial part for a cruise liner in order to serve the customers with maximum comfort onboard and considering the wave added resistance in calculating the total resistance of hull form for selecting the appropriate engine power. Therefore, this work is motivated by the challenge to understand and clarify which approach is particularly suited for the performance of seakeeping behavior of the hull form design and select the optimum hull form design considering a couple of scenarios of different sea-states of operating routes and different speeds. In this thesis, parametric modeling of the hull form is modified from the original geometry model of the ship hull which is provided from Meyer Shipyard by using Friendship Framework/CAESES. After getting parametric model, it is simulated by GL Rankine and validated with experimental results from HSVA. GL Rankine is coupled with CAESES and then, with different optimization approaches, optimal ship hull form is obtained in calm water condition. The optimized model is checked for wave added resistance and analyzed for seakeeping behavior in moderate sea-state under different scenarios. In the another approach, the hull form is directly optimized for the total resistance of the ship, comprising the calm water resistance and the added resistance in seaway, followed by the analysis of seakeeping behaviors. Optimization is to be done especially on the fore body of the hull (e.g. bulbous bow). Finally, the results are analyzed to compare the optimal hull form with original design.