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Towing cable arrays have made significant contributions across various fields, and their outspread process is crucial for realizing their functionalities. However, research on the dynamic characterization of the outspread process of towed cable arrays lacks systematic organization. This paper reviews, organizes, and analyzes the outspread process of towing cable arrays, drawing on relevant models, case studies, and structural features. It ingeniously applies concepts from parachute outspread to the analysis of towing-cable-array deployment. The study systematically examines the deployment of towing cable arrays under varying cable lengths, wave conditions, and the interactions between line arrays. The goal is to integrate existing research on the outspread of towing cable arrays, addressing the gaps in the description of this process and providing a comprehensive analysis of the outspread characteristics under different conditions. Additionally, this paper identifies current limitations in this area and provides insights for future developments. Furthermore, it explores the potential application of AI to address these challenges. The aim of this paper is to contribute meaningfully to this field.

Referring to the specific parameters, working environment and cabling mode of a seawater desalination device, this paper used OrcaFlex, a large-scale marine hydrodynamic analysis software, to establish a hydrodynamic analysis model of the mooring system of the marine floating desalination device. It also studied the operation process of the model, combined the mooring system and the combined effect of wind, wave and current, analyzed the mooring tension change and hydrodynamic force of the mooring cable, and guiding suggestions and detailed requirements for the design and construction of the tethered system were put forward.

The conventional mooring positioning technique is cost-effective; however, it shows poor maneuverability and positioning precision. In this study, to calculate the mooring tension, mooring cables were discretized into lumped mass models using the lumped mass technique. Dock fender nonlinear response forces were modeled in OrcaFlex using the Link unit. The multi-body system’s entire coupling vibrant time-frequency features have been examined. The effect of the side thrusters on removing the vessel motion carried on by the first-order wave loads has been determined under mooring conditions by comparing the difference in horizontal degree of freedom motion and the mooring line’s mooring tension between dynamic and non-dynamic positioning vessels (DPV). The impact of the wharf-cable and target position on side thrusters and positioning capabilities are analyzed, considering the results of both vessels under identical environmental loads. The results demonstrate that deep evaluation of the target position can greatly improve side thruster performance and ship positioning precision. DP systems are weak to cancel linear wave forces, and the missing ship motions for DP ships may be due to the combined action of the fender, moorings and the selection of a good target position. When the selection of the target position is unreasonable, the size of the pre-tension of the mooring line cannot meet the requirement of absorbing the first-order wave load on the vessel.

When analyzing the dynamic characteristics of marine cables, the static equilibrium state must first be calculated; a dynamic analysis can then be carried out based on the static equilibrium. Since the calculation of the static equilibrium is the basis of dynamic calculation, different methods for the calculation of the static equilibrium will have important impacts on the dynamic response characteristics of cables, which result in cables having different dynamic characteristics. This paper summarizes the research progress in the effects of different methods for the calculation of the static equilibrium on the dynamic response of marine cables during the releasing process, and current methods for their static calculation are more comprehensively developed as well as being more accurate. To study the influence of different static equilibrium calculation methods, with the reference of some specific parameters of a mooring cable, combined with specific sea conditions, through the necessary simplification of the cable releasing process, based on the lumped mass method, mooring cables are discretized into the lumped mass model, and dynamic analysis models of the releasing process of mooring cables under three methods for the calculation of the static equilibriums (the fast static equilibrium calculation method, the analytic catenary calculation method, and the catenary calculation method) are established. The dynamic characteristics of the spatial configurations of mooring cables based on different static equilibrium calculation methods are obtained through time domain coupling analyses. It was found that if the static equilibrium of a cable is calculated, taking into account gravity, buoyancy, wave current resistance, inertia forces, and the axial stiffness of a cable, then the characteristics of a cable during dynamic descent are closest to that of a real situation. The calculation results have a certain guiding significance for specific engineering practices.

Waves have an important influence on the motion performances of offshore crane vessels. The floating crane vessel in waves gives rise to the motion of the lifted object which is connected to the hoisting wire. Based on the geometric parameters of a revolving offshore crane vessel, combined with the specific process of the floating crane vessel at work, a model of the offshore crane vessel under full-circle swing hoisting has been established by OrcaFlex. With the change in wave direction, the dynamic response of the system is made and the impact force between the support vessel and the hanging object and the tension of the crane wire under different wave directions is obtained. At the same time, the minimum impact forces between the support vessel and the hanging object and the tension of the crane wire and their wave directions are obtained. According to the calculated result, the optimal design of the full-circle swing hoisting operation of large revolving offshore crane vessel has been determined.

The trawl system plays an irreplaceable role in deep-sea fishing. In the towing process of the trawl system, many complex mechanical phenomena occurs, so it is necessary to analyze the dynamic response of the deep-sea trawl system during the towing process. In this paper, an equivalent mathematical model for predicating the movement of the ocean trawl system is established based on the equivalent net theory. In the proposed method, the lumped mass method is used to simulate the towed cable and some lines with hydrodynamic characteristics are used to simulate the fishing net. The effects of towing speeds on the dynamic characteristics of a rigid truss trawl system and a flexible trawl system during straight-line towing and rotation towing are studied. The results show that it is possible to simulate trawl motion, and the trawling process is well-presented using this equivalent mathematical model. The disadvantage of this method is also obvious, that is, it cannot simulate trawls with a large number of meshes because the proliferation of mesh numbers can lead to difficult computational convergence. The results also demonstrate that during straight-line towing, the higher the speed, the greater the tension of the cable. Due to the rigid truss, the shape of the rigid truss trawl under different towing speeds is not much different, while the shape of the flexible trawl system changes greatly. During rotating towing, the tension of the cable changes abruptly in the initial stage, and then fluctuates periodically in the time domain. With the increase of towing speed, the overall outward floating distance of the trawl increases gradually. This study has a certain reference and guiding role for deep-sea fishing operations.

The coupling effect between the offshore platform and the riser in the offshore platform-riser multi-body system might be greatly increased under heavy external maritime stresses. The system will become significantly more nonlinear. The partial secondary development of OrcaFlex is carried out considering the strong non-linearity of the dynamic positioning (DP) offshore platform-riser multi-body system, combined with the actual offshore construction engineering background and the lumped mass method, based on Python-language embedded programming with the basis of the operation principle of the application program interface (API) and the composition of its modules. To regulate the dynamic positioning of the offshore platform-riser multi-body coupling system, a UKF-PID control approach based on an unscented Kalman filter is presented. Based on the procedures described above, a classical calculation model is created, and the model’s calculation results are compared to those of relevant references, confirming the method’s validity and viability. Finally, the model of the PID-controlled dynamic positioning offshore platform-riser rigid–flexible multi-body system is developed, and a dynamic simulation is performed under specified sea conditions. The findings have implications for engineering practice.