Mooring Research Of New-type Floating Structure

Floating structures are subjected to complex external forces such as wind,waves and current when produced or serviced in a specific aquatic environment.In harsh environments,these forces will cause large drifts in the floating structure,which can cause adverse effects and even damage the structure.It is of great significance to provide a suitable mooring system for floating structures to stabilize working position and ensure safety.Unlike mature offshore oil and gas development equipment,floating photovoltaic power(PV)station and deep-sea aquaculture platform are two new floating structures,which have their own characteristics in structure,working environment and operation requirements.In this paper,the two new floating structures are studied,and a series of studies from environmental load assessment to mooring performance analysis are provided,which provides a basis for the development of such floating structures and other new floating structures.The computational fluid dynamics(CFD)method was used to analyze the current load and wind load distribution of 170m×170m floating PV station.The reliability of numerical simulation was verified by model test.In order to solve the problem of insufficient precision caused by large-scale CFD calculation,a "2.5D" method for improving the global calculation accuracy by local fine calculation is proposed.Based on the potential flow theory,the wave loads of the solidified square arrays are solved,and the mooring static forces of the floating square arrays are calculated by combining the wind loads and the current loads.The effects of the horizontal span and the water level of the mooring arrays on the mooring performance are explored.The research idea simplifies the movement problem of the ultra-multiple floating body which is difficult to solve under the wave.The current load and wind load of the deep-sea aquaculture platform are predicted by the combination of CFD numerical calculation and model test.The method proposed in this study is more accurate than the empirical formula method.The wave load and hydrodynamic coefficient of the aquaculture platform are solved based on the potential flow theory of the floating body moving in the wave.The tank sloshing problem of twelve large-scale aquaculture tanks was studied from the perspective of influencing the platform movement response.The conclusions indicate that the tank sloshing has a great influence on the platform movement and should be considered in the mooring study.In this paper,a single-chain catenary anchor leg mooring system suitable for deep-sea aquaculture platforms was proposed.A single chain catenary mooring system suitable for deep-sea aquaculture platform is proposed.Based on the indirect time-domain theory,the time-domain coupled motion analysis of the aquaculture platform and mooring system is carried out.The original design of mooring system is optimized.Finally,the effects of the maximum connection conditions on the motion response and mooring economy of the aquaculture platform mooring design are discussed,which can provide reference for the operation planning of the aquaculture platform.