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[Introduction] The ship resistance directly affects the fast performance of the ship, for an offshore wind farm service vessel, the fast performance is one of the important performance indexes. Therefore, it is necessary to calculate the ship resistance and study the effective resistance optimization method. [Method] Based on the CFD method, a numerical model was established to study the resistance performance of a 19.1 m-long catamaran offshore wind farm service vessel, the resistance of the ship at four different speeds of 10 kn, 13 kn, 16 kn and 20 kn were calculated and analyzed, and a stern flap was installed at the stern of the ship as the optimization method. Three stern flap schemes with different installation angles were designed. The ships before and after optimization were numerically simulated, and the calculation results were compared and analyzed. [Result] The research shows that the installation of stern flap with appropriate installation angle at the stern of the ship can effectively improve the resistance performance of the ship during navigation. The resistance reduction effect is ideal. The optimization method can change the navigation attitude of the ship and reduce the heave and trim angle of the ship during navigation. [Conclusion] The research results can provide reference for the calculation of ship resistance performance and the design of optimization method.

[Introduction] The suction bucket jacket is a new type of offshore wind turbine foundation with many advantages, and its vibration characteristics are obviously different from those of traditional foundations. Correctly handling the boundary conditions of the infinite foundation is very important to accurately analyze the vibration problem, so this paper analyzes the vibration characteristics of the suction bucket jacket offshore wind turbine under different boundary conditions. [Method] Taking a suction bucket jacket offshore wind turbine as the analysis object, a full three-dimensional finite element model of structure and soil coupling was established in ANSYS APDL, the influence of boundary conditions on the natural frequency was studied, and the sensitivity analysis of related parameters was carried out. [Result] Different boundary conditions have a great influence on the natural frequency of the whole structure. Changing the boundary conditions has a greater influence on the axial stiffness and torsional stiffness than the bending stiffness of the structure. The natural frequency of the whole structure increases with the spring stiffness of the viscoelastic boundary, the elastic modulus of the soil, and the coefficients of friction between the bucket and soil. [Conclusion] The related factors that affect the calculation accuracy of the natural frequency of the whole structure are analyzed, which can provide references for engineering calculations.

Limited by scaling effects, the physical model tests of FOWTs (floating offshore wind turbines) cannot simulate the aerodynamic loads on rotors correctly. To solve this problem, the real-time hybrid model tests in wind tunnels were developed and provided a feasible solution for the aerodynamic simulation. To perform the wind tunnel tests, the design of aerodynamic equivalent rotor models is most critical. In this study, an innovative methodology of aerodynamic equivalent design for the wind turbine rotors is developed based on GA (genetic algorithm). The NREL (National Renewable Energy Laboratory) 5 MW and DTU (Technical University of Denmark) 10 MW rotors are employed for the case studies to validate the proposed methodology. According to the results, the model-scale aerodynamic thrust performance can be accurately matched with the prototype in the entire region between cut-in and cut-out wind speeds, which allows the rotor model to provide correct thrust at different wind speeds. The variance of the aerodynamic torque with the wind speeds for the developed model is also in good agreement with the prototype, which could be beneficial for the design of the model-scale active pitch control strategy. Moreover, the applicability of the fitness functions of GA is discussed. [ABSTRACT FROM AUTHOR]

It will be a new approach that BIM’s capital project lifecycle management (CPLM) applied to the yacht industry. This paper explored the feasibility of applying the principles and rationales of BIM for capital project lifecycle management in luxury yacht design, engineering, fabrication, construction and operation. The paper examined the premises and backbone technology of BIM. It then evaluated leading naval engineering and shipbuilding software applications and their development trends from the functional lens of BIM. To systematically investigate a BIM-based approach for capital project lifecycle management (CPLM) in the luxury yacht industry, the paper proposed and outlined an implementation framework. A case study and a student competition use case were discussed to delineate the core constituents and processes of the proposed framework. The case of BIM was reviewed. Through the domestic custom luxury yacht design and prototyping student competition, the application of this framework in educational research is demonstrated and the initial quantitative assessment of the framework is carried out. Conclusions: a BIM-based CPLM implementation framework can help the luxury yacht industry capitalize on the global transformation to an information-centric and data-driven new business paradigm in shipbuilding with integrated design, manufacturing and production.