Abstract
The safety of unmanned ship berthing is of paramount importance. In order to explore the influence of wind and wave coupling, a berthing computational fluid dynamics (CFD) model was established, and the characteristics of speed field, pressure field, and vortex have been obtained under different speed, wind direction, and the quay wall distances. The results show that the total resistance of the hull against the current can be about 1.60 times higher compared to the downstream resistance, water flow resistance is the dominant factor, accounting for more than 80% of the total resistance. When changing the distance between ship and shore at fixed speed, the results found that the torque is small, but the growth rate is very large when driving below 2 m/s, and the torque growth rate is stable above 2 m/s. Based on the established coupling model, a multi-factor berthing safety study is carried out on an actual unmanned ship. The results show that when the speed increases from 4 m/s to 12 m/s, the curve slope is small, the resistance increases from 3666 N to 18,056 N, and the rear slope increases. The pressure increases with the speed, and when the speed is 24 m/s, the maximum pressure is up to 238,869 Pa. When the wind speed is fixed, the vertical force of the unmanned ship increases first and then decreases to zero and then reverses the same law change, and the maximum resistance is about 425 N at the wind angle of about 45 degrees; At 90 degrees, the maximum lateral force on an unmanned boat is about 638 N. The above results can provide control strategy for unmanned ship berthing safety, and provide theoretical basis for unmanned ship route planning and obstacle avoidance, safety design, etc.
Highlights
Unmanned ships are widely used in marine exploration and development, island reef resupply, marine environmental monitoring, improving the energy efficiency and environmental performance of ports and terminals [1]
Chen Yuanchao et al solved the viscous Reynolds average Navier–Stokes (RANS) equation to determine the flow field, supplemented by the volume of fluid (VOF) and dynamic grid method for the three aspects of hydrostatic resistance, seakeeping, and maneuverability prediction, and the results showed that the numerical simulation scheme had high accuracy in the prediction of static water resistance of ships at medium and low speeds, but it was not suitable for the prediction of resistance of high-speed navigation
The grid was divided, the boundary was set, and the unmanned ship, wind and wave coupling computational fluid dynamics (CFD) model was established under the influence of various factors
Summary
Unmanned ships are widely used in marine exploration and development, island reef resupply, marine environmental monitoring, improving the energy efficiency and environmental performance of ports and terminals [1]. Chen Yuanchao et al solved the viscous RANS equation to determine the flow field, supplemented by the volume of fluid (VOF) and dynamic grid method for the three aspects of hydrostatic resistance, seakeeping, and maneuverability prediction, and the results showed that the numerical simulation scheme had high accuracy in the prediction of static water resistance of ships at medium and low speeds, but it was not suitable for the prediction of resistance of high-speed navigation. CFD model is established, and the berthing safety of unmanned ship is studied considering factors such as ship speed and direction, wind speed, and the distance between ship and shore. Based on the established coupling model, a multi-factor berthing safety study is carried out on an actual unmanned ship
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
