Study on Energy Efficient Operation by ship's Trim Optimization based on Computational Fluid Dynamics

The prediction and optimization on resistance characteristics of marine vessels are getting important due to maritime environmental pollution, climate changes, impacts on human health near the coastal area and so on. Therefore, several methods were developed to reduce the fuel consumption of the vessel to improve the voyage performance. Among them, the trim optimization method is one of the popular methods to reduce the fuel consumption of ships. Trim optimization can be done by changing the trim by moving the cargo or ballast water and also can be applied on both new and existing ships. Moreover, this method needs not to change any structural arrangement or machinery of the vessels to apply it. Therefore, in this paper, this method was evaluated by using computational fluid dynamics with the help of commercial software Star-CCM+. Firstly, the numerical analysis of resistance data for KRISO Container Ship (KCS) in even keel were carried out and compared with experimental data from the model test to validate the results. After that, the optimum trim values for different service speeds were estimated using the calculated resistances. It is found that trim optimization at various speeds can be an effective and convenient way for vessels to decrease fuel consumption, emission of harmful substances and improve the energy efficiency by reducing the total drag force. Therefore, it could be one of the most practical ways to improve the environmental friendliness for both new and existing ships and also to fulfill the environmental related regulations.