To investigate the internal sound field of an enclosed cabin equipped with intake and exhaust ducts, numerical acoustic simulations were conducted using the acoustic module of the finite element software LMS Virtual Lab. The study focused on acoustic performance indicators such as the insertion loss of the intake and exhaust mufflers and examined the influence of the intake muffler on the cabin's sound field. The simulation results indicate that the pressure losses of the intake and exhaust mufflers are 19 kPa and 72 kPa, respectively, both meeting the design requirements. Within the frequency range of 20 Hz to 20 kHz, the insertion loss of both mufflers generally complies with the standard, though certain frequency bands still require further optimization. Specifically, the overall noise reduction effect of the intake muffler is slightly lower than that of the exhaust muffler, while the exhaust muffler’s noise attenuation performance in the high-frequency band needs improvement. From the cabin perspective, installing mufflers in the intake duct effectively reduces mid- and high-frequency noise inside the cabin. Additionally, accumulated water in the cabin smooths the sound spectrum and reduces noise, with this effect gradually stabilizing as water depth increases. This study provides valuable insights for optimizing the acoustic design of ship cabins.

To investigate the advantages of the toroidal propeller in hydrodynamic performance and the characteristics of its blade surface pressure distribution, this study first examined the configuration parameters of the toroidal propeller. A parametric modeling approach was applied to the entire propeller, leading to the development of a first-generation toroidal propeller model. Subsequently, based on the STAR-CCM+ software, the open-water performance and pressure distribution of the propeller were computed using the Detached Eddy Simulation (DES) turbulence model. A second-generation toroidal propeller was then developed by adjusting the pitch distribution, which optimized the surface pressure distribution. The research indicates that the configuration design of the toroidal propeller requires the introduction of new parameters. The open-water performance of the toroidal propeller follows a trend similar to that of conventional propellers, but its maximum efficiency is not ideal. The total thrust of the toroidal propeller is considerable; however, the selection of the airfoil and parameters may be unreasonable, leading to pressure loss in both the pressure and suction sides of the front blade and consequently degrading the surface pressure distribution to some extent. Adjusting the pitch distributions of the front and rear blades of the toroidal propeller can significantly optimize the pressure distribution on the blade surface.

Subsea pipelines are prone to developing cracks during long-term service, and traditional methods often suffer from low localization accuracy and poor stability in complex noisy environments. This study investigates defect localization based on an improved cross-correlation time delay estimation method for acoustic emission (AE) signals, which is significant for identifying and localizing sudden AE events under challenging conditions. AE detection technology, as a dynamic, real-time, and non-destructive evaluation method, captures transient elastic waves generated by internal structural changes due to stress or environmental variations, enabling early warning of potential damage and accurate health monitoring of structures. Experimental results demonstrate that the improved cross-correlation time delay method effectively enhances the localization accuracy for AE sources, achieving an average localization error of 0.0133 m and a relative error of 2.67%, which sufficiently meets practical requirements. The findings indicate that this method possesses high practical value for damage detection and localization analysis in complex structures.

As a lift-based energy-saving device, sails are increasingly deployed on modern ships to reduce fuel consumption and carbon dioxide emissions. This study investigates the performance of a NACA airfoil sail installed on a bulk carrier and identifies suitable areas for sail placement. Computational Fluid Dynamics (CFD) simulations were employed to analyze the flow fields around both the sail and the ship. The simulation results show good agreement with Experimental Fluid Dynamics (EFD) data. A comparison between the onboard sail and a freestanding sail reveals that the hull-induced airflow disturbance alters the lift characteristics of the sail. Furthermore, by analyzing the wind speed distribution above the deck under different wind directions, areas with higher wind speeds were identified, determining a "high-performance zone" more suitable for sail layout. This study provides valuable guidance for developing sail arrangement strategies in practical engineering applications.

To facilitate the rational development of engine-propeller integrated control curves and improve the loading response and rapid starting of vessels equipped with a Combined Diesel And Diesel (CODAD) system, mathematical models for the diesel engine, gearbox, shafting, and propeller were established. By analyzing shortcomings of the original emergency loading strategy, an optimized strategy was proposed that prioritizes increasing the rotational speed before adjusting the rate of pitch change. Dynamic simulation results of the CODAD system demonstrate that the optimized strategy ensures that the engine power remains within the overload limit while significantly accelerates the response to engine commands and vessel starting. Compared with three representative strategies, the speed stabilization time under optimized strategy is reduced by 76.6 s, 37.6 s, and 23.8 s, respectively, and the command loading time is shortened by 78.3 s, 35.4 s, and 24.7 s, correspondingly. The simulations also reveal the power variation pattern during emergency loading of large vessels: the main engine power initially increases, then decreases, and finally stabilizes as the vessel's speed steadies. This study provides valuable insights for formulating overload protection strategies and optimizing engine-propeller matching design.

The longitudinal coaming of the liquefied natural gas (LNG) carrier’s cargo tank dome is typically subjected to significant longitudinal loads during operation, leading to stress concentration and potential failure at the toe of the end bracket. To address this issue, a shape optimization study was conducted on the end bracket structure. The optimization process sequentially employed orthogonal experimental design, intuitive analysis, comprehensive experimental design, and a GA-BP-GA (Genetic Algorithm-Back Propagation-Genetic Algorithm) hybrid method for stepwise refinement. The results demonstrate that through shape optimization, the maximum stress of the bracket was reduced by 22.9% compared to the original design. The influence of various design variables on the maximum stress decreases in the order of horizontal arm length ( L), toe height ( h), and arc radius ( r). The introduction of dimensionless parameters C_L and C _r reveals that C_L exerts a greater influence on the maximum stress than C_r. A lower maximum stress is observed when the stress concentration is located at the arc edge. Furthermore, the optimal structural dimensions, which yield a lower maximum stress located at the arc edge, correspond to C_L values ranging from 1.15 to 1.25 and C_r values ranging from 1.1 to 1.3. The optimization design process, methodology, and related conclusions presented in this study can provide valuable references for the design of ship bracket structures.

Green and environmental sustainability are perpetual themes in the shipping industry. Driven by the "Dual Carbon" policy and emerging technologies, new energy vessels and green ships have become an irreversible trend. This paper begins by employing the Strengths-Weakness-Opportunities-Threats (SWOT) analysis to review the development trends of domestic green shipping and lithium-battery powered ships. Subsequently, taking the coastal Yangtze River Delta region as a case study, it systematically analyzes the strengths, weaknesses, opportunities, and threats associated with developing the lithium-battery powered ship industry in this area. The study reveals that, influenced by resources, policies, and environmental factors, the coastal Yangtze River Delta region possesses significant advantages for developing this industry. However, it also faces challenges such as inadequate infrastructure, competitive pressures, and technological risks. In response to these issues, this paper proposes targeted optimization strategies to provide insights for the long-term and sustainable development of the lithium-battery powered ship industry.

This paper addresses the control problem of uncertain systems subject to external disturbances, unknown nonlinearities, and input saturation constraints in ship heading control. A nonlinear regulation control algorithm is designed that integrates adaptive neural networks with dynamic surface control (DSC) technology. The algorithm employs a radial basis function (RBF) neural network to approximate external disturbances and unknown nonlinear functions, while the integration of DSC technology effectively reduces computational complexity. A nonlinear function featuring error-dependent gain characteristics is incorporated into the control law design. This adaptive nonlinear control approach effectively eliminates potential singularity issues, while an auxiliary system is designed to compensate for the effects of input saturation constraints. Using Lyapunov stability theory, the uniform ultimate boundedness of all closed-loop signals is rigorously proven. The proposed algorithm is validated through MATLAB simulations of ship heading tracking control under input saturation constraints. Comparative experimental results demonstrate the superior performance and advantages of the proposed method. The findings provide both theoretical foundations and practical references for related fields, demonstrating significant application value in ship engineering practice.

This study investigates the hydrodynamic response of polar transport ships under ice-propeller-rudder multi-body interactions in brash ice channels. The study develops a numerical ice tank and a discrete element model for brash ice using a coupled Computational Fluid Dynamics-Discrete Element Method (CFD-DEM) integrated with overset grid technology. The research analyzes the self-propulsion characteristics of ships navigating in brash ice channels. The reliability of the Discrete Element Method (DEM) is validated through quantitative comparisons between numerical results and experimental data for ice-induced resistance. The analysis examines the influence of propeller rotational speed on the hydrodynamic performance of the propeller-rudder system under different loading conditions, considering both ice-free and ice-covered environments. Results indicate that the propeller rotational speed required to achieve the self-propulsion point at scantling draft condition is higher than that required at design draft condition. Furthermore, the study compares the force characteristics of the propeller-rudder system in both time and frequency domains, contrasting environments with and without brash ice. These findings provide valuable insights for predicting ice loads and ensuring navigational safety of ships in ice-covered waters.

The Moving Particle Semi-implicit (MPS) method is a meshless method based on the Lagrangian perspective. It effectively avoids mesh distortion when simulating problems with large free-surface deformations, such as water entry and exit of structures, numerical wave generation, and dam breaks. Additionally, its free surface detection algorithm is straightforward and ensures accurate interface tracking, showing broad application prospects. To date, research on numerical wave generation using the MPS method has primarily focused on wave-structure interactions, with relatively limited validation analysis dedicated to the wave generation process itself. To address this gap, this study establishes a two-dimensional numerical wave tank model based on the MPS method, incorporating an improved particle shifting scheme and stabilization operators. Regular waves were generated using a piston-type wavemaker and numerically absorbed in a damping zone. Multiple sets of regular waves with different parameters were simulated to analyze the influence of damping coefficients on the results. Furthermore, the model was validated against experimental motion data of a floating box in waves. The results demonstrate that the proposed model can accurately simulate regular waves with various parameters. The wave amplitude error is positively correlated with the reflected wave energy, and selecting appropriate damping coefficients can effectively minimize the influence of reflected waves on the numerical results. Moreover, the simulated motion time history of the floating box agrees well with the experimental data, confirming the feasibility of the model for solving wave-structure interaction problems.

A Coal Tar Pitch (CTP) tanker is a specialized chemical tanker developed from conventional petroleum asphalt tankers. This vessel type undergoes significant modifications to meet enhanced damage stability requirements. In recent years, the widespread application of dual-fuel systems, particularly methanol, has presented significant challenges for damage stability design in such vessels. Taking an 8000 DWT petroleum asphalt tanker as a case study, this study analyzes its tank subdivision arrangements, loading characteristics, and damage stability performance. The study compares design requirements and damage stability criteria between petroleum and coal tar pitch asphalt tankers, and analyzes the impact of deck-mounted methanol fuel tanks on damage stability. Optimization measures including tank subdivision redesign, loading pattern adjustments, and flooding point reconfiguration are implemented to enhance vessel performance. These modifications ensure that the converted vessel complies with damage stability criteria when converting to a coal tar pitch asphalt tanker configuration.

As the global shipping industry accelerates its transition toward low-carbon, digital, and intelligent development, emerging technologies including artificial intelligence (AI), the internet of things (IoT), big data, and automatic control systems are profoundly transforming the shipbuilding industry. This transformation has positioned maritime autonomous surface ship (MASS) at the strategic forefront of international maritime technology competition. Although China has launched numerous R & D projects in autonomous ships and has made substantial progresses, challenges persist, such as unclear market demand and inadequate technological drivers. This study selects green-fueled container ships as the primary research focus, addressing their intelligence and autonomy requirements in actual shipping environments. The study identifies four core development directions and constructs a hierarchical logical architecture for autonomous ships. Subsequently, it investigates the application of autonomous technologies in the maritime domain. Furthermore, the paper analyzes evolution trends of autonomous ships and identifies shortcomings in key technological breakthroughs and institutional frameworks. Based on the analysis, targeted development pathways are proposed to facilitate R & D advancement, practical implementation, and systematic capability-building for autonomous ships in China, providing strategic guidance for the industry’s development.

With advancements in computer technology and numerical simulation methods for hydrodynamics, performance-driven ship optimization has become an important approach for improving the hydrodynamic performance of ships. Ship optimization comprises several key components, including parametric modeling, hydrodynamic performance evaluation, surrogate model construction, and optimization algorithms. This paper reviews developments in ship optimization technologies, summarizes typical methods and their characteristics associated with each component, and identifies challenges including high-dimensional design spaces, multidisciplinary coupling, and practical engineering applications. On this basis, the paper focuses on the development and application of OPTShip-SJTU, a ship optimization software independently developed by the Computational Marine Hydrodynamics Laboratory (CMHL) at Shanghai Jiao Tong University. The software integrates parametric modeling, in-house hydrodynamic performance solvers, multiple surrogate models, and optimization algorithms. This enables a fully automated process from geometric modification to performance evaluation and optimization, establishing a ship optimization platform with proprietary intellectual property rights. Through validation via numerous engineering applications and academic studies on various ship types, OPTShip-SJTU has demonstrated effectiveness and reliability in comprehensive ship performance evaluation and optimization. The software provides an advanced tool and solution for China's shipbuilding industry.

Annual maintenance is an important measure in ship maintenance reform and is crucial for enhancing ship operational availability and maintaining technical conditions. Currently, the schedule control of annual maintenance projects still relies on traditional management models, which often result in lengthy maintenance cycles. To improve the traditional methods, this paper introduces coefficients for uncertain factors, process location, time elasticity, and resource utilization, based on the Critical Chain Technology (CCT) theory. A calculation method for the project buffer is established, and a schedule control model for annual maintenance projects based on CCT is constructed. The applicability of the model is verified through a case study of an annual maintenance project. The results show that the application of Critical Chain Technology effectively enhances project management, control, and execution capabilities, while significantly shortening the annual maintenance cycle.

In the alignment calculation process for propulsion shafting systems equipped with shaft-mounted generators, the unbalanced magnetic pull (UMP) is often overlooked, leading to deviations and reduced accuracy in the alignment results. To investigate the influence of the UMP of a shaft-mounted generator on the dynamic alignment of a propulsion shafting system, a finite element model for shafting alignment was established based on a simplified modeling principle. Dynamic alignment analyses were conducted under various conditions: without a shaft-mounted generator, with a shaft-mounted generator but without considering UMP, and with a shaft-mounted generator while considering different UMP values. A comparative analysis of the calculation results was performed. The results demonstrate that the UMP of the shaft-mounted generator affects the shaft deflection, stress, and the load on adjacent bearings. The research findings provide valuable guidance and reference for the accurate alignment calculation of propulsion shafting systems equipped with shaft-mounted generators.

On ships using methanol as fuel, the vent mast of the methanol tank is a potential release point for methanol vapor, which may be released during navigation or bunkering operations. As a toxic substance, excessive inhalation of methanol can harm crew health. Classification rules require a minimum distance of 15 meters between the methanol vent mast and non-watertight openings in accommodation areas. Consequently, the vent mast is typically positioned away from accommodation areas during the design phase. However, some smaller vessels may be unable to meet this requirement due to layout constraints. Furthermore, the extent of the influence of methanol vapor released from the vent mast is affected by factors and conditions such as the release rate, ambient wind speed and direction, and the aerodynamic profile of the surrounding structure. Relying solely on the 15-meter spacing requirement is insufficient to determine whether a release from the vent mast during actual operation could lead to personnel exposure to toxic concentrations. Therefore, this study employs computational fluid dynamics (CFD) simulations to analyze gas dispersion from a methanol vent mast located at the bow of a methanol-fueled ship under different wind speeds. The research aims to investigate the extent of the methanol toxic zone and to verify that the hazardous area generated by the vent mast does not endanger crew health.

Accidents involving chemical tankers are often highly hazardous. The operational status of cargo tanks and loading/unloading systems is critical to the safety of these ships during service. This paper reviews 62 accident cases related to the cargo tanks and loading/unloading systems of chemical tankers occurring between 2003 and 2021. A statistical analysis of the accident causes is conducted from four perspectives: accident type, deadweight tonnage of the involved ship, ship age, and the ship's operational status at the time of the accident. This analysis aims to summarize the conditions under which these accidents occur. Thirty-one typical cases are selected for a more detailed examination. The potential risks leading to these accidents are categorized into human factors and non-human factors. Finally, targeted control measures are proposed, including suggestions for chemical tanker rules and standards, as well as recommendations for the management and operational requirements of shipping companies. These measures are intended to provide technical support for enhancing the safety of chemical tanker transportation.

To investigate the patterns of ship detention defects in Port State Control (PSC) inspections and reduce the probability of ship detention, this paper constructs an association rule analysis model for ship detention defects based on an improved Apriori algorithm, considering the characteristics of PSC inspections and ship attributes. Using the PSC inspection data of detained ships from the Tokyo Memorandum of Understanding (Tokyo MOU) between 2018 and 2023 as the research sample, the study first processes the ship attribute data by applying association rule mining technology to perform dimensionality reduction and discrete standardization, thereby forming effective samples for analysis. An improved Apriori algorithm, which incorporates constraints on both antecedent and consequent and introduces the evaluation metric of confidence boost, is employed to conduct an in-depth mining analysis of ship detention defects. Empirical results demonstrate that the improved Apriori algorithm can efficiently screen out significant strong association rules and accurately reveal the patterns of ship detention defects. These patterns can provide an important basis for ship safety risk management and help enhance navigation safety.

To enhance the reliability and effectiveness of ship magnetic protection capability evaluation, thereby facilitating better magnetic stealth strategy formulation and improved survivability, a study on objective weighting methods for the evaluation indicators of ship magnetic protection capability was conducted. To address the issue of obtaining objective weights for these indicators, the entropy weight method and the Criteria Importance Through Intercriteria Correlation (CRITIC) method were employed for weight assignment. The applicability of these two objective weighting methods in the evaluation of ship magnetic protection capability was analyzed. Furthermore, the impact of variations in the volume of indicator data on both weighting methods was investigated. The research demonstrates that changes in the amount of indicator data have a relatively minor impact on the CRITIC method. As the data volume changes, the maximum average relative error of the weighting results obtained by the CRITIC method is only 2.19%, with a maximum standard deviation of merely 0.002 5. Case analysis indicates that the weighting results of the CRITIC method are more stable than those of the entropy weight method, making it more suitable for the objective weighting of evaluation indicators for ship magnetic protection capability.

The selection of structural materials is a critical aspect in the design of ships operating in polar low-temperature environments. Currently, the requirements of relevant rules from different classification societies exhibit both similarities and differences. The lack of a unified definition for the design temperature poses significant challenges in the selection of hull steels for polar service. Through a systematic review of the rules pertaining to material selection for hull structures in polar low-temperature environments, and based on differences in their foundational principles and definitions of design temperature, these rules can be categorized into three main types: IACS Unified Requirement S6 (UR S6) along with the winterization rules of classification societies, the POLAR CLASS (PC) rules and the rules of the Russian Maritime Register of Shipping (RMRS). This paper conducts a comparative analysis of the differences among these three categories of rules, covering aspects such as the scope of application, design temperature, and steel grade selection. Valuable conclusions and suggestions are summarized, which are expected to provide a reference for the selection of hull steels in polar low-temperature environments.

This study investigates the ultimate strength of container ships under the combined action of vertical and horizontal bending moments. The ultimate strength of three container ships with different specifications is calculated using single-span finite element models, and the influence of loading sequence and path on the results is discussed. A revised failure envelope equation for the ultimate strength of ultra-large container ships under biaxial bending moments is proposed. Using finite element software, the stress-strain characteristics of stiffened panels are obtained, both with and without initial stresses. Based on this, the existing load-end shortening curve for stiffened panels is improved. A simplified incremental iterative method for calculating the hull girder's ultimate strength under biaxial bending moments is then proposed. A comparison between the results from the nonlinear finite element method and those from the proposed method demonstrates that the latter achieves high computational accuracy, along with simplicity of operation and ease of programming. The findings of this research can be applied to the calculation and analysis of the ultimate strength of container ship hull girders under biaxial bending moments.

In the fields of hull structure construction, maintenance, and digital twinning based on digital technology, a reliable positioning method is required to achieve real-time alignment between a ship's digital model and the coordinate system of the physical structure, thereby determining the position of data acquisition points within the hull model's coordinate system. This paper utilizes a lightweight RGB-D camera to acquire image data of the hull structure. Visual feature extraction algorithms are employed to obtain structural features. A method for real-time coordinate alignment between the image data and the 3D model data based on the feature data is proposed, enabling fast and accurate alignment of the image and model coordinate systems. The method first extracts linear features from a prior 3D model of the structure to define the model coordinate system. It then generates corresponding linear features in the 3D reconstruction space from the depth and color images captured by the RGB-D camera. Finally, based on a linear registration algorithm, the fusion of the prior 3D model and the reconstructed model is achieved, enabling the real-time calculation of the positions of the RGB-D camera’s acquisition points within the coordinate system of the structural 3D model.

Data conversion between ship CAD software and hull prescriptive design software is a crucial step in achieving model-based integrated 3D digital design. This paper investigates the requirements and technical pathways for bidirectional data conversion between Smart3D (S3D) and the hull prescriptive design software Mars2000 (Mars). A secondary development of the S3D software was conducted using the VB.NET language. The tool extracts data related to plating, compartments, and longitudinal stiffener connection nodes at transverse section positions from the full ship model through longitudinal range traversal and filtering. Based on custom rules, the extracted data is converted according to the Mars modeling method, and a Mars model file is exported. Subsequently, by comparing files, the tool identifies modifications made in the optimized Mars model and automatically updates the S3D model accordingly. Tests and validations performed on a 114,000 DWT oil tanker demonstrate that the bidirectional data conversion between S3D and Mars is accurate and efficient. The time required for model conversion using the tool is approximately 1/20 of the time needed for manual modeling, and the model update time is reduced to about half of the manual modification time.

As proposed in the revised MSC.1/Circ.1533 (2016), evacuation analysis should be performed to evaluate escape routes at an early stage of ship design. Accordingly, this paper introduces how to apply the evacuation analysis method to guide the general arrangement design of passenger ships in the early design stage. The study deeply analyzes the mutual influence between the evacuation analysis method and the general arrangement design, focusing on three decisive parameters of the total evacuation time. These include the influence of vertical spatial division on the staircase passage time (tstair), the influence of deck horizontal layout on the deck movement time (tdeck), and the influence of crowding and queuing on the flow time (tF). Incorporating evacuation analysis in the early stage of passenger ship design aims to achieve rational planning of the ship's escape routes. This approach helps to avoid excessive sacrifice of the general arrangement space and effectively prevents major subsequent modifications, while meeting the performance requirements of the evacuation analysis. An overview of existing domestic research reveals that most studies remain at a superficial level. Therefore, efforts in evacuation analysis research should be gradually increased to lay a foundation for the independent research and development of high-end passenger ships in China.

To accurately assess the overall energy efficiency of cruise ships and propose optimization strategies, it is necessary to establish calculation formulas for evaluating the energy efficiency of various onboard systems, combined with actual ship data analysis to reveal the characteristics of energy consumption distribution. This paper first constructs a typical model of the energy-consuming systems on a cruise ship, including the propulsion system, electrical system, and thermal system. Then, based on the first law of thermodynamics, corresponding calculation formulas and methods for the energy consumption, work output, and energy loss of each system are established. A comprehensive voyage calculation and analysis for a medium-sized luxury cruise ship is conducted. The analysis of the results reveals that the energy consumption of equipment and systems related to passenger services accounts for a high proportion, approximately 50% of the ship's total energy consumption. This finding shows a significant discrepancy from the simplified approach used in the International Maritime Organization (IMO)'s Energy Efficiency Design Index (EEDI) calculation for luxury cruise ships, where the auxiliary engine power is treated as a fixed percentage (about 5%) of the main engine power. The results of this study provide a methodological foundation for assessing the overall energy efficiency of cruise ships, lay the groundwork for proposing future revisions to the IMO's energy efficiency assessment methodology for cruise ships, and offer insights for optimizing the energy efficiency design of new cruise ships and retrofitting existing ones.

With the growing global emphasis on environmental protection and sustainable development, the shipping industry is facing severe pressure to reduce emissions and save energy. As a clean and renewable energy source, wind energy demonstrates significant potential in the field of ship auxiliary propulsion. This paper takes the KVLCC2 ship as the research object and establishes a three-degree-of-freedom mathematical model for ship motion. The thrust and moment generated by a specific type of sail on the hull in a wind field are introduced as additional terms into the model, enabling the simulation of the sail-assisted ship's motion under wind conditions. Simulation studies on the turning and zigzag motions of the sail-assisted ship reveal that the sail has a significant impact on the ship's maneuverability. Under a wind speed of 8 m/s, the sail increases the ship's turning drift distance by 38.4 m (accounting for 12% of the ship's length) while also increasing the ship's speed during the turning process by 28.1%. In zigzag motion, the sail increases the ship's overshoot angle, particularly during upwind turns, where the second overshoot angle increases from 18.4° to 25.7°. Under beam wind conditions (±90°), the sail induces an asymmetric effect on the ship's steering. The auxiliary effect of the sail is more pronounced during downwind steering, whereas upwind steering requires an increase in the rudder angle for compensation.

The deep-sea green intelligent technology test vessel “WEI LAI” is designed primarily for tasks including the pilot testing of green intelligent technologies, surface support for deep-sea equipment, and comprehensive marine scientific surveys. It features a rational overall layout, strong retrofitting and reconfiguration capability, flexible equipment integration, excellent maneuverability, a high degree of intelligence, and powerful testing capabilities. It serves as a crucial cornerstone for supporting the intelligent upgrading and green development of key systems and equipment and for promoting the transformation and industrialization of scientific and technological achievements. This paper briefly describes the functional orientation of the "WEI LAI" vessel and analyzes its design requirements from the aspects of functional diversification, whole-vessel modularization, and system intelligence. It then presents the overall schemes for the ship type and general arrangement, modular retrofitting design, and key systems, including the power redundancy and hybrid propulsion system, intelligent information system, integrated platform for intelligent and dynamic testing, power system sea trial verification platform, dynamic testing system, and test collaborative control system. This paper can provide references for the development of special test vessels for marine equipment.

Polar research vessels demand increasingly greater endurance due to their special scientific research missions. A marine plant factory solution is proposed to address the problem of vegetable shortage for long-endurance polar research vessels, ensuring continuous supply of vegetables. The applied research of plant factory technologies for polar research vessels is conducted by discussing the key technologies, environmental control requirements and type selection of marine plant factories. A design method for the plant factory on long-endurance polar research vessels is then presented to provide references for ship designers.

The wheelhouse windows will be iced by seawater droplet and climatic conditions such as rain and snow for vessels operating in extreme cold environments. It will obstruct the view from the wheelhouse and thus threaten the navigation safety, making the deicing design for the wheelhouse windows critically important. Aiming at optimizing the deicing effect of the wheelhouse windows under extreme cold environments, it studies the causes of icing on the surface of the wheelhouse windows. Using this as input conditions, the electric heating deicing of the wheelhouse windows are numerically simulated and analyzed to provide the deicing effect of different electric heating powers under different external ambient temperatures. An electric heating deicing solution is finally proposed for the wheelhouse windows under extreme cold environments.

A ship interior outfitting design system using virtual simulation technology is developed to address the limitations of the traditional ship interior outfitting design system, including lack of intuitiveness, poor interaction and long design iteration cycles. 3ds Max has been used for 3D modeling, and the realism of the model and the real-time nature of the system are considered through refined modeling and optimization processing. A virtual environment based on the Unreal Engine 4 is established to complete the model import, material allocation, collision setup and lighting optimization, together with efficient connection to a MySQL database through C++ plug-ins. The system integrates the functions of resource management, dynamic adjustment of design schemes and perceptual engineering evaluation, and develops diversified interactive logic through blueprint technology to improve the user experience. The test results show that the system can accurately present the three-dimensional model and material effects of the interior outfitting design, realize the function of real-time interaction and perceptual engineering evaluation, thereby meeting the basic requirements of ship interior outfitting design. Users can intuitively adjust design schemes and obtain visualized evaluation feedback through the system. The system has good intuitiveness and operability, enhancing the presentation quality of the design scheme and user experience. It provides an innovative solution for the ship interior outfitting design.