Explore the vast range of titles available.

Skeg in barge maintains stability, while transom is responsible for influencing the fluid resistance of barge. Therefore, this research aimed to discuss the effect of angle variations in skeg and transom on resistance and seakeeping. Analysis was performed on variables such as drag coefficient to angle variation, RAO to the response given by waves in translation and rotation, and the value of wave frequency. The analytical results showed that the variation of transom below the waterline increased the resistance of barge while the variation of skeg angle affected barge’s stability and maneuverability. Additionally, seakeeping analysis obtained data to understand barge in various sea weather situations. This signified that each varied skeg angle affected drag and seakeeping effects. Following this exploration, the research is expected to contribute to barge technology.

In recent years, the pollution of ecological waters, especially the litter floating on the ocean surface, has emerged as a pressing economic, political, and environmental concern of the international society. The development of a widely applicable, safe, reliable and cost-saving marine surface litter collection device has drawn considerable attention. In this paper, an innovative shallow-sea floating surface litter collection device (later referred to as SFSLCD) is proposed first, including its concept design, dimensions and key parameters, working scheme, and mooring system. Second, the hydrostatic and hydrodynamic characteristics of SFSLCD are derived through numerical modeling. Last, the safety of SFSLCD in normal and rough sea states is validated in terms of its good seakeeping performance using the coastal condition of Dapeng Bay, Shenzhen, China. It is proven that this litter collection device equipped with photovoltaic panels to supply power can operate in waters of depth between 5 and 15 m in seas, rivers and lakes.

In order to explore the influence of vessel speed on seakeeping characteristics and provide valuable insights for ship performance evaluation, the accurate prediction of ship motion and resistance in wave conditions is essential. In this study, the variations in ship motion and resistance with respect to ship speed are analyzed during navigation in regular waves. The results suggest that the added resistance coefficient of the KCS demonstrates an initial rise, succeeded by a subsequent decline, with the expansion of wavelength. Moreover, the peak non-dimensional resistance coefficient, observed at different ship speeds, demonstrates an upward trend with the augmentation of ship velocity. This research methodology provides a valuable tool for numerically predicting the hydrodynamic performance of vessels in regular wave conditions.

The main research is to investigate the seakeeping effect resulting from general FPSO hull bow flare. CFD-FV (Computational Fluid Dynamics-Finite Volume) method is applied with fluent software to simulate in the 3D time domain. Simulation objects are two different bow flare models exposed to the green water phenomenon, which is under the sea state of the Brazilian sea 20 years of return extreme sea state. Seakeeping analysis includes green water. The results indicated that a 3.5 m vertical bow flare would reduce about 35.09% level of green water on deck. A comprehensive comparison indicated that bow flare improved the global seakeeping performance, which can be used as a reference to the design of general FPSO hull bow flare.

In this paper, the seakeeping performance of unmanned underwater vehicle (AUV) under the action of transverse waves is calculated and analyzed, based on the commercial CFD software STAR-CCM+. The test data verifies the reliability of the numerical calculation method. The roll and heave response of the vehicle under different working conditions provide a reference for the overall parameter design of the unmanned underwater vehicle.

Although the institutional history of ancient Chinese maritime trade has been extensively documented, the functional evolution of maritime vessels and their underlying drivers remains underexplored. Recent studies have moved beyond political explanations to explore the interplay of economic and technological dynamics. Using KH Coder for text mining, this study applies word frequency analysis and co-occurrence network modeling to investigate the geopolitical factors shaping the morphological evolution of Guangdong merchant ships in the Ming and Qing dynasties. A visual-comparative analysis further assesses the functional attributes of three representative ship types. Findings reveal that economic and military imperatives were the primary determinants of ship design, with political and geographic factors exerting secondary but supportive influence. For instance, increased piracy threats in the South China Sea prompted structural reinforcements for defensive purposes, while policy shifts under the Canton System encouraged hull designs optimized for high-capacity, long-distance trade. Guangdong’s maritime development was shaped largely by its strategic location and shipbuilding technologies. Ming-era vessels, constructed from teak and cedar, featured brightly painted, flat-bottomed hulls with elevated, streamlined prows. Qing-era ships employed lightweight alloys, muted color schemes, and reinforced double-planked hulls to enhance seaworthiness, while bow structures evolved into sharper and more angular forms. As Guangdong’s maritime trade transitioned from coastal routes to long-distance transoceanic networks—particularly with Europe—its ship design shifted progressively from broad and bulky to agile and eventually more durable configurations. These morphological transformations reflected not only external pressures, such as maritime security concerns and trade expansion, but also internal drivers, including institutional reforms and policy realignments that significantly influenced vessel design. This study contributes to the technical dimension of maritime historiography by emphasizing the merchant ship as an analytical nexus of institutional logic, technological systems, and geopolitical conditions. It offers both theoretical insight and methodological innovation for understanding the mechanisms behind ship design evolution and the spatial organization of premodern Chinese maritime networks.

The hydrodynamic performance of the floating body in seawater is very important. The wave buoy is a small buoy that measures wave parameters such as wave height and wave direction, for the non-powered wave buoy, the hydrodynamic performance mainly refers to the seaworthiness of the buoy body. Seakeeping refers to the motion law of the floating body in the wave. For the wave buoy, the seakeeping of the floating body has an important impact on the measurement of wave data. Therefore, the analysis of the hydrodynamic performance of the wave measurement float is an important reference for evaluating the performance of the wave buoy. In this paper, the hydrodynamic performance of cylindrical and spherical wave-finding buoys is compared and analyzed, and the influence of different structural forms on their hydrodynamic performance is analyzed, which provides a reference for optimizing the hydrodynamic performance of wave-measuring buoys.

Hydrodynamic model-scale experiments are an intrinsic part of the design of marine structures, as they enable validating and calibrating the involved hydrodynamic numerical models. Such seakeeping experiments are generally conducted using a simple spring-based mooring system, with fixed properties throughout the tests. In the context of cyber-physical testing, the marine structure is kept in position in the laboratory by a virtual mooring system, the properties of which can be adjusted on the fly. This paper provides an algorithmic approach for maximizing the information gain from the test by optimizing the mooring stifness and damping parameters that define the experiment. The method is verified with synthetic data generated for the INO Windmoor 12MW floater, and is shown to be robust to noise and unmodeled effects.

An experimental campaign has been undertaken to explore the flow around a feeder vessel as it manoeuvres in and out of the well dock of a mothership. The parent hulls for this study are drawn from the floating harbour transhipper concept created by Sea Transport Corporation. Laser measurement techniques have been employed to analyse the flow field within the well dock while the feeder vessel both enters and departs. For the Master of the feeder vessel to safely perform these manoeuvres, the complex flows resulting from the highly confined nature of the well dock concept need to be understood and potentially mitigated. It is shown that the inclusion of vents in the well dock can significantly influence the flow and that their effectiveness is determined by the size of the vents. This study further progresses the authors’ recent work on the same novel concept where the confined water effect of the well dock and inclusion of vents is quantified for both the seakeeping behaviour and the docking/departure performance. It is concluded that the use of vents is very beneficial when a feeder vessel docks or departs the well dock, however a compromise on the vent size must be reached in order to reduce adverse effects on feeder vessel motions when docked and exposed to a seaway. It is likely that the optimum solution, that covers all operational parameters, only requires the inclusion of relatively small vents.

The continuous increase in worldwide ship traffic poses relevant challenges on the management of the onboard safety during navigation and specific operations. Among these issues, navigation in relatively shallow water areas, being either channels or port areas, is of major interest especially when rough weather conditions occur due to the increased risk of grounding. Such a problem, which is deeply related to the seakeeping performance of a ship, can be tackled by different perspectives. In the present paper, the approach proposed by the PIANC recommendations, typically used to design port and channels areas and infrastructures, are analysed from the perspective of ship design hence dealing with its operability. In particular, the dynamic Underwater Keel Clearance (UKC) of a ship is studied based on direct seakeeping computations to assess the effect of the operability conditions in terms of sea states and ship speed at different wave encounter angles.