Browse Topic: Marine vehicles and equipment

Items (1,205)
Since the trial operation of the Three Gorges ship lift, in order to improve its functions, some equipment and structures have been modified, mainly including the modification of the filling and emptying system for docking, the modification of the bollard, and the modification of the operation platform and so on. This has led to an increase in the weight of the ship chamber, which may have adverse effects on the structure of the ship chamber, steel wire ropes, drive system motors, and safety mechanisms. Based on the compilation and analysis of relevant data including technical documentation modifications, on-site investigations, and drive system tests, this study determines the actual loads and boundary conditions of key components such as the ship chamber structure and wire ropes at the current stage. Combined with finite element analysis methods, it calculates the strength and stiffness of the existing ship chamber structure, verifies the safety factors of the wire ropes and the
Cheng, HangLu, MingmingWang, DiYang, HuaWu, FanFan, ZhuoQin, Feng
In view of the complex intertidal terrain challenges faced by offshore wind power maintenance, this paper optimizes the lightweight design of multi-terrain tracked vehicles. The structure was optimized by finite element analysis, and the maximum stress was 211.68 MPa ( lower than the safety limit of 230 MPa), and the maximum deformation was 5.25 mm, which ensured the stability and stiffness. Titanium alloy has the advantages of high strength, low density and corrosion resistance, which improves the durability of the frame while reducing the weight of the frame. Advanced manufacturing technologies such as phase transformation superplastic diffusion welding optimize the connection between TC4 titanium alloy and stainless steel. Modal analysis and optimization techniques refine the structural parameters and improve the complex load performance. The research promotes the lightweight of the frame and provides theoretical and technical support for the design of multi-terrain vehicles.
Xu, HanXu, ShilinMa, WenboZhu, Wei
This paper attempts to introduce a unique water transport system by using open-bottomed air tanks in a water transport vehicle and using horizontal buoyancy instead of vertical buoyancy. This study explains how a certain amount of horizontal buoyancy is generated by attaching open-bottomed air vessels to commonly used small watercraft. In contrast to the fact that vehicles generally require a lot of water for all water transport, this new mode of transport can use a minimal amount of water, as appropriate for the weight, through a sufficient literature survey. The proposed water–air–based vehicle integrates open-bottomed air vessels with a hydrofoil system to generate horizontal propulsion. A model analysis is conducted to explain how the horizontal buoyancy force generated by the air vessels is related to the vertical buoyancy force, and their values at different depths are tabulated. The vehicle model can achieve a maximum speed of 1.5 m/s, handling 20–70 kg payload, highlighting
Santhiyagu, Arulanantha Samy
This study focuses on the multifunctional three-body high-speed unmanned boat model, and experimentally measures the roll attenuation characteristics under different draft conditions. It focuses on the influence of the initial roll angle on roll attenuation, and analyzes the change pattern of roll angle over time. Experimental results show that the model shows obvious self-oscillation period and amplitude attenuation. Based on the system identification theory and combined with improved genetic algorithms, a mathematical model used to simulate the roll attenuation motion of the boat model was constructed. The difference between experimental data and fitted values was further evaluated using identification software and verified with data at specific roll angles. In addition, the study also deeply analyzed the change trend of the roll moment coefficient with the initial roll angle. By comparing the experimental results of the three-mall boat and the catamaran, it was found that the three
Zhang, DiTong, WeiYu, QingzhuLiu, Bofei
Producing 3D models of cooling water passages of outboard motors, and calculating distribution of electric potential on the water passage surfaces using BEM, we have developed the new method for simulation of electric potential distribution. The outboard motor is a propulsion system attached to the transom of the boat with steering function. As the water around the boat is drawn in for cooling of the engine, the engine parts are susceptible to severe corrosion. As a means to help prevent corrosion, a part referred to as the anode metal, which has a lower natural potential, is provided. Such a method is called the sacrifice protection because the anode metal corrodes before the engine parts due to the difference of electric potential. Since anti-corrosion currents occur preferentially to areas close to the anode metal, the anode metal is required to be located at the most effective place for corrosion protection. However, there are certain restrictions in the layout of anode metal from
Shibuya, RyotaSuzuki, Hiroki
Type IV composite pressure (CP) vessels composed of a plastic liner and composite layers require special design attention to the dome region. The cylindrical portion of the composite cylinder is wrapped with composite layers consisting of the 900 hoop layers and low-angle helical layers, whereas the dome surface carries helical layers only. The winding angle of the helical layers being a constant over the cylindrical portion starts to vary from the cylinder-dome junction toward the boss at the top continuously. Along with the winding angle, the composite thickness also varies continuously resulting in a maximum thickness at the top crown region. The complete analysis and layer-wise stress prediction of Type IV composite cylinders for service pressures up to 70 MPa was analyzed by the Classical Lamination theory (CLT)-based MATLAB program. The MATLAB program developed in this work for the dome initially performs the dome profile generation through the numerical integration of the dome
R. S., NakandhrakumarTandi, RonakM, RamakrishnanRaja, SelvakumarElumalai, SangeethkumarVelmurugan, Ramanathan
For further elucidation of the extremely complex mechanism of wall heat transfer during diesel flame impingement, heat flux measurement results based on two different relatively new approaches, high-speed infrared thermography and Micro Electro- Mechanical Systems (MEMS) heat flux sensor, were compared. Both measurements were conducted on the chamber wall impinged by a diesel flame achieved in constant volume combustion vessels under similar experimental conditions. Infrared thermography was conducted using a high-speed infrared camera (TELOPS M3k, 13,000 fps, 128×128 pixels), allowing the capture of time-series temperature and heat flux distributions on the wall surface with a spatial resolution of 70 μm (9 mm / 128 pixels). This high-resolution imaging also enables detailed estimation of near-wall turbulent structures, which are considered to significantly influence the heat flux distributions. The MEMS sensor is composed of closely aligned (520 microns separated) multiple highly
Shimizu, FumikaMorooka, MasatoAizawa, TetsuyaDejima, KazuhitoNakabeppu, Osamu
This SAE Recommended Practice establishes the procedure for determining if recreational motorboats have effective exhaust muffling means when operating in the stationary mode. It is intended as a guide toward standard practice and is subject to change to keep pace with experience and technical advances.
Marine Technical Steering Committee
This SAE Recommended Practice establishes the procedure for measuring the sound level of recreational motorboats in the vicinity of a shore bordering any recreational boating area during which time a boat is operating under conditions other than stationary mode operation. It is intended as a guide toward standard practice and is subject to change to keep pace with experience and technical advances.
Marine Technical Steering Committee
This SAE Recommended Practice establishes the procedure for measuring the maximum exterior sound level of recreational motorboats while being operated under a variety of operating conditions. It is intended as a guide toward standard practice and is subject to change to keep pace with experience and technical advances.
Marine Technical Steering Committee
To address the issue of intermittent engine intervention during the charging and discharging processes of hybrid vehicles, which results in roaring noise within the cabin, this paper proposes a semi-coupled cluster control strategy that offers superior overall performance. This strategy is based on the traditional multi-channel Active Noise Control (ANC) system and integrates the advantages of both centralized and decentralized control approaches. The proposed clustered control strategy reduces computational load by approximately 50% compared to the centralized control strategy, while maintaining comparable noise attenuation performance. Moreover, it demonstrates significantly improved stability over the decentralized control strategy, with outstanding noise reduction results. Using the MATLAB simulation platform, the performance of the proposed in-vehicle clustered control strategy is compared with that of traditional control strategies. Additionally, road test experiments are
Deng, HuipingLu, ChihuaChen, WanLiu, ZhienChen, PianDou, SiruiSun, Menglei
Additive manufacturing has been a game-changer in helping to create parts and equipment for the Department of Defense's (DoD's) industrial base. A naval facility in Washington state has become a leader in implementing additive manufacturing and repair technologies using various processes and materials to quickly create much-needed parts for submarines and ships. One of the many industrial buildings at the Naval Undersea Warfare Center Division, Keyport, in Washington, is the Manufacturing, Automation, Repair and Integration Networking Area Center, a large development center housing various additive manufacturing systems.
Real-world data show that abdominal loading due to a poor pelvis-belt restraint interaction is one of the primary causes of injury in belted rear-seat occupants, highlighting the importance of being able to assess it in crash tests. This study analyzes the phenomenon of submarining using video, time histories, and statistical analysis of data from a Hybrid III 5th female dummy seated in the rear seat of passenger vehicles in moderate overlap frontal crash tests. This study also proposes different metrics that can be used for detecting submarining in full-scale crash tests. The results show that apart from the high-speed videos, when comparing time-series graphs of various metrics, using a combination of iliac and lap belt loads was the most reliable method for detecting submarining. Five metrics from the dynamic sensors (the maximum iliac moment, maximum iliac force drop in 1 ms, time for 80% drop from peak iliac force, maximum pelvis rotation, and lumbar shear force) were all
Jagtap, Sushant RJermakian, Jessica SEdwards, Marcy A
Amphibious vehicles are widely used in civil and military scenarios due to their excellent driving performance in water and on land, unique application scenarios and rapid response capabilities. In the field of civil rescue, the hydrodynamic performance of amphibious vehicles directly affects the speed and accuracy of rescue, and is also related to the life safety of rescuers. In the existing research on the hydrodynamic performance of amphibious vehicles, seakeeping performance has always been the focus of research by researchers and amphibious vehicle manufacturers, but most of the existing research focuses on the navigation performance of amphibious vehicles in still water. In actual application scenarios, amphibious vehicles often face complex water conditions when performing emergency rescue tasks, so it is very important to study the navigation performance of amphibious vehicles in waves. Aiming at the goal of studying the navigation performance of amphibious vehicles in waves
Zhang, Yu
The rapid advancement of inland waterway transport has led to safety concerns, while real-time high-precision positioning in maritime contexts is essential for enhancing navigation efficiency and safety. To tackle this problem, this paper proposes a method for enhancing the accuracy of maritime Real - Time Kinematic (RTK) positioning using smartphones based on multi-epoch elevation constraints. Firstly, the elevation characteristics of smartphones in a maritime context were analyzed. Subsequently, exploiting the feature of gradual elevation variations when vessels navigate inland rivers, an appropriate sliding window was established to construct elevation constraint values, which were then integrated into the observation equations for filtering computations to boost positioning accuracy. Finally, synchronous observations were carried out using smartphones and geodetic receivers to compare and analyze the positioning accuracy before and after the addition of the elevation constraints
Wumaier, DiliyaerYu, XianwenMu, Hongbo
In response to the complex shore slope road conditions and the switching of water–land environments during the amphibious vehicle’s landing process, a landing drive force control strategy for amphibious vehicles is proposed. First, based on the shore slope gradient, buoyancy effect, and amphibious vehicle acceleration, the drive force of the front and rear wheels of the amphibious vehicle is pre-allocated. Then, referring to the road parameters of common road types, the road adhesion coefficient and optimal slip ratio of the current road surface where the amphibious vehicle is located are identified based on the principle of fuzzy control. Subsequently, with the slip ratio difference as the control target, the drive motor is controlled based on the sliding mode control algorithm to achieve tracking of the optimal slip ratio. A joint simulation is carried out using CarSim and Simulink, and the results are compared with those without control. The simulation results show that the drive
Huang, BinYuan, ZinengYu, Wenbin
Unmanned Underwater Vehicles (UUVs) are used around the world to conduct difficult environmental, remote, oceanic, defense and rescue missions in often unpredictable and harsh conditions. A new study led by Flinders University and French researchers has now used a novel bio-inspired computing artificial intelligence solution to improve the potential of UUVs and other adaptive control systems to operate more reliability in rough seas and other unpredictable conditions.
Since the rapid development of the shipping and port industries in the second half of the twentieth century, the introduction of container technology has transformed cargo management systems, while simultaneously increasing the vulnerability of global shipping networks to natural disasters and international conflicts. To address this challenge, the study leverages AIS data sourced from the Vessel Traffic Data website to extract ship stop trajectories and construct a shipping network. The constructed network exhibits small-world characteristics, with most port nodes having low degree values, while a few ports possess extremely high degree values. Furthermore, the study improved the PageRank algorithm to assess the importance of port nodes and introduced reliability theory and risk assessment theory to analyze the failure risks of port nodes, providing new methods and perspectives for analyzing the reliability of the shipping network.
Li, DingCheng, ChengZhao, XingxiLi, Zengshuang
Path planning algorithms are critical technologies for intelligent ship systems, as scientifically optimized paths enable safe navigation and efficient avoidance of waterborne obstacles. To address the limitations of current ship path planning models, which often fail to adequately consider the combined effects of wind, current, and the International Regulations for Preventing Collisions at Sea (COLREGS), this study proposes an enhanced path planning method. The method integrates environmental factors, such as wind and current, and COLREGS into an improved Artificial Potential Field(APF) framework. Specifically, the influence of wind and current is modeled as "environmental forces," while the navigation constraints imposed by COLREGS are transformed into virtual obstacles, generating corresponding repulsive forces to refine the algorithm. Simulation experiments conducted under both single-ship and multi-ship scenarios validate the feasibility and effectiveness of the proposed approach
Shangqing, FengJinli, XiaoLangxiong, GanGeng, ChenHui, LiGuanliang, Zhou
This study focuses on developing and deploying an Unmanned Aquatic Vehicle (UAV) capable of underwater travel. The primary objectives of this project are to detect the presence of dimethyl sulfide and toluene, as well as to identify any potential oil leakage in underwater pipelines. The UAV has a maximum operating depth of 300 m below the water surface. The design of this UAV is derived from the natural design of Rhinaancylostoma, an underwater kind of fish. The maximum operational setting for this mission is fixed at a depth of approximately 300 m beneath the surface of the sea, and the choice of this species is suitable for fulfilling the objectives of this undertaking. This technology will mitigate the risk associated with human interaction in inspection processes and has the potential to encompass various other resources in the future. The initial design data of the UAV is determined using analytical processes and verified formulas. The selection of the airfoil is done by comparing
Veeraperumal Senthil Nathan, Janani PriyadharshiniRajendran, MahendranArumugam, ManikandanRaji, Arul PrakashSakthivel, PradeshMadasamy, Senthil KumarStanislaus Arputharaj, BeenaL, NatrayanRaja, Vijayanandh
This work addresses an innovative method for improving energy harvesting in Bladeless wind turbines (BWT) by implementing profile modifications to the wind turbine for fixing it in Unmanned Surface Vehicles (USV). The streamlined flow undergoes a transformation and generates a vortex in the vicinity of the structure when the wind impacts the BWT. As the velocity increases, the wind strikes the structure with greater force, resulting in an imbalance that causes the structure to vibrate. To convert this vibrational energy of the wind turbine into electrical energy, the research investigates the use of a variety of profile modifications to capitalize on the aerodynamic effect generated by the structure. The entire cylindrical shape is altered to tapered shape, airfoil shapes with coordinates such as NACA 0012, 0015, 0018, 4412 and 4420. In addition to these shapes, hybrid models were also constructed by merging models made from two airfoil coordinates, including NACA 0018 & 4412, NACA
Veeraperumal Senthil Nathan, Janani PriyadharshiniRajendran, MahendranArumugam, ManikandanRaji, Arul PrakashSakthivel, PradeshStanislaus Arputharaj, BeenaL, NatrayanGanesan, BalajiRaja, Vijayanandh
The integration of advanced horizontal axis turbines (HATs) into unmanned marine vehicles (UMVs) significantly enhances their operational efficiency by providing power sources. These vehicles, designed for diverse applications, require efficient power systems to operate autonomously over extended periods. The major disadvantages are limited battery life and energy storage capabilities that restrict the operational range and endurance of the UMVs. Utilizing HATs in UMVs provides a renewable energy source, reducing operational costs. This continuous power supply enhances mission capabilities and promotes energy independence, making them ideal for long-term missions. Thus, using Computational fluid dynamics (CFD) models, hydrodynamic and aerodynamic analyses were carried out. For the hydrodynamic scenario, a velocity of 10 m/s and for the aerodynamic case, 27.7778 m/s, were taken into consideration. It is concluded that the UMV with Stepped HAT modification can be effectively employed for
Gunasekaran, Durga DeviKannan, HaridharanSourirajan, LaxanaVinayagam, GopinathGnanasekaran, Raj KumarKulandaiyappan, Naveen KumarStanislaus Arputharaj, BeenaL, NatrayanRaja, Vijayanandh
This SAE Recommended Practice establishes recommended procedures for the issuance, assignment, and structure of Identification Numbers on a uniform basis by states or provinces for use in an Assigned Identification Number (AIN).
VIN - WMI Technical Committee
Anduril Industries Orange County, CA Contact@anduril.com
NASA engineers have developed a new approach to mitigating unwanted motion in floating structures. Ideally suited to applications including offshore wind energy platforms and barges, the innovation uses water ballast as a motion damping fluid. Various designs have been developed to suit a number of different configurations depending on the specific applications.
Nowadays, the energy transition is at the most critical moment. In order to achieve the emission reduction target of ships, a form of boosting piston inside methanol fuel injector has been carried out. The physical property fluctuations and phase change of methanol under high pressure have been considered in the design phase. 1D-3D coupling method is used to comprehensively evaluate the performace of the injector. To this end, an Amesim simulation model is established to systematically study and analyze the injection characteristics. The injection performance of the injector under four typical loads are calculated, which is evaluated from the perspectives of injection quantity, injection duration, valve response, and leakage of boost components. In the nozzle block, the cavitation intensity of methanol is stronger than that of diesel. To reduce the possibility of cavitation erosion, as a consequence, a CFD model is established to optimize the structure of nozzle components. By adding
Yang, LiWen, LimingZhang, HanwenLu, GangaoDong, Weijie
Innovators at the NASA Johnson Space Center have developed a novel foot-pedal-operated system and device to control movement of an object in three-dimensional (3D) space. The Foot Pedal Controller system enables operators to control movement of spacecraft, aircraft, and watercraft using only foot pedals. This design leaves the hands free for simultaneous operation of other equipment.
The following list consists of hose data provided as of December 2024 and is for convenience in determining acceptability of nonmetallic flexible hose assemblies intended for usage under 46 CFR Part 56.60-25. Where the maximum allowable working pressure (MAWP) or type of fitting is not specified, use the manufacturer’s recommended MAWP or type of fitting. This list has been compiled by SAE staff from information provided by the manufacturers whose product listings appear in this document. Manufacturers wishing to list their products in this document shall: a Successfully test their hose to the requirements of SAE J1942, Table 1. b Submit a letter of certification to the SAE J1942 test requirements for each specific type of hose tested (see sample table, Table 1) along with the test results. All sizes should be included in the same letter, which must also include all of the information necessary to make an SAE J1942-1 listing. c SAE will review the letter and may, at their discretion
Hydraulic Hose and Hose Fittings Committee
Shipbuilders didn’t have the option of fiberglass when the nonprofit American Bureau of Shipping (ABS) was established 160 years ago to help safeguard life and property on the seas. Fortunately, technology to help better ensure the safety of ocean vessels has also come a long way in that time, in part because people have become a spacefaring species.
Northrop Grumman San Diego, CA jacqueline.rainey@ngc.com
Measuring fluid mass in microgravity, where fluid behavior is dominated by fluid properties, is a challenging problem. To address this problem engineers at NASA are developing a capacitance-based, mass-fraction gauge for vessels containing two-phase fluids. The vessel volume is enclosed with an array of electrodes, and a unique set of capacitance measurements of the enclosed volume are made between the electrodes. The capacitance measurements are scaled with appropriate weighting factors derived from Laplace’s Equation to compensate for the highly non-uniform electric fields inside the measurement volume and achieve a greater level of mass fraction accuracy.
Curtiss-Wright Corporation Davidson, NC info@curtisswright.com
The scope of this SAE Recommended Practice is limited to cranes mounted on a fixed platform lifting loads from a vessel alongside. The size of the vessel is assumed not to exceed that of a work boat as defined in 3.14.
Cranes and Lifting Devices Committee
MIT researchers have developed a battery-free, self-powered sensor that can harvest energy from its environment. Because it requires no battery that must be recharged or replaced, and because it requires no special wiring, such a sensor could be embedded in a hard-to-reach place, like inside the inner workings of a ship’s engine. There, it could automatically gather data on the machine’s power consumption and operations for long periods of time.
This SAE Recommended Practice specifies graphic symbols for operator controls, gauges, tell-tales, indicators, instructions, and warning against risks in small craft and for engines and other equipment intended to be used in small craft.
Marine Technical Steering Committee
For taking counter measures in advance to prevent accidental risks, it is of significance to explore the causes and evolutionary mechanism of ship collisions. This article collects 70 ship collision accidents in Zhejiang coastal waters, where 60 cases are used for modeling while 10 cases are used for verification (testing). By analyzing influencing factors (IFs) and causal chains of accidents, a Bayesian network (BN) model with 19 causal nodes and 1 consequential node is constructed. Parameters of the BN model, namely the conditional probability tables (CPTs), are determined by mathematical statistics methods and Bayesian formulas. Regarding each testing case, the BN model’s prediction on probability of occurrence is above 80% (approaching 100% indicates the certainty of occurrence), which verifies the availability of the model. Causal analysis based on the backward reasoning process shows that H (Human error) is the main IF resulting in ship collisions. The causal chain that maximizes
Tian, YanfeiQiao, HuiHua, LinAi, Wanzheng
Electrified vehicles represent mobility’s future, but they impose challenging and diverse requirements like range and performance. To meet these requirements, various components, such as battery cells, electric drives, fuel cells, and hydrogen vessels need to be integrated into a drive and storage system that optimizes the key performance indicators (KPI). However, finding the best combination of components is a multifaceted problem in the early phases of development. Therefore, advanced simulation tools and processes are essential for satisfying the customer´s expectation. EDAG Engineering GmbH has developed a flat storage platform, which is suitable for both, BEV and FCEV. The platform allows for the flexible and modular integration of batteries and hydrogen vessels. However, package space is limited and the impact of the design choices regarding the vehicle’s KPI need to be considered. Therefore, EDAG has developed a simulation model that combines automated 3D design and packaging
Viehmann, AndreasNauck, NiklasEsser, ArvedSchramm, Michael
With the increasing demand for efficient & clean transport solutions, applications such as road transport vehicles, aerospace and marine are seeing a rise in electrification at a significant rate. Irrespective of industries, the main source of power that enables electrification in mobility applications like electric vehicles (EV), electric ships and electrical vertical take-off & landing (e-VTOL) is primarily a battery making it fundamentally a DC system. Fast charging solutions for EVs & e-VTOLs are also found to be DC in nature because of several advantages like ease of integration, higher efficiency, etc. Likewise, the key drivers of the electric grid are resulting in an energy transition towards renewable sources, that are also essentially DC in nature. Overall, these different business trends with their drivers appear to be converging towards DC power systems, making it pertinent. However, DC circuit protection poses serious challenges compared to AC due to the absence of natural
Milind, T. R.Thomas, AmalRastogi, SarthakK, Satyadeep
Defense Innovation Unit Washington D.C. info@DIU.mil
Mild steel and AISI 304 L have gained widespread usage across diverse industries, such as naval vessels, boilers, aviation, and automobile sector, due to their ready availability and distinct attributes. Fusion welding techniques have been employed to join this alloy, which is known for its specific qualities. The strength of welded joints is directly proportional to a certain percentage of the strength exhibited by the base materials. However, the welding process becomes intricate when dissimilar steels need to be joined. In such cases, achieving consistent and reliable welding become a challenge. Therefore, meticulous attention is required in the selection of electrodes, filler wires, and other operational parameters, such as current, voltage, and shielding gas. Among the solid-state joining methods, FW (Friction Welding) stands out as an excellent approach to achieving robust joints. This technique ensures strong joint formation. In this study, two pivotal FW parameters viz
Hari Prasath, S.Abishek, D.Hamshavardhan, S.Sankar Guru, K.Gunasekaran, K.N.
Amphibious vehicles with both land and water navigation functions have extremely high application value in the military and civilian fields. In order to fully utilize the wheel driving force and ensure the smooth landing of the amphibious vehicle driven by four wheel hub motor, an acceleration slip regulation (ASR) is designed under the condition of landing from water. First, the road friction coefficient is identified based on the back propagation neural network (BPNN). Then, utilizing the improved Burckhardt model, the current optimal slip ratio is calculated from the identified road friction coefficient. Finally, the ASR under the condition of landing from water is designed based on radial basis function (RBF) single neuron adaptive PID control algorithm. By analyzing the process of amphibious vehicles transitioning from water to land, a typical working condition for amphibious vehicles landing is established, and a joint simulation is conducted using CarSim/Simulink. The simulation
Huang, BinXu, JialuoYuan, ZhijunWei, Lexia
MIT engineers aim to produce totally green, carbon-free hydrogen fuel with a new, train-like system of reactors that is driven solely by the sun. In a study appearing Solar Energy Journal, the engineers lay out the conceptual design for a system that can efficiently produce “solar thermochemical hydrogen.” The system harnesses the sun's heat to directly split water and generate hydrogen — a clean fuel that can power long-distance trucks, ships, and planes, while in the process emitting no greenhouse gas emissions.
This SAE Standard establishes a uniform test procedure and performance requirement for limiting the maximum speed of a personal watercraft.
Personal Watercraft Committee
The sinking and trimming of the hull in the channel would directly affect the handling and navigation safety of the ship. In view of the ship sinking, a series of empirical formulas to estimate the subsidence have been put forward for vessel in spacious shallow water areas. However, most of the equations are based on seagoing vessels. They are not suitable for inland ships with small scales, shallow drafts, and narrow navigation width. Till now, research on ship squat in intermediate channel has not yielded more practical results. Here, a generalized physical model is used to study the sinking of 500t class ships in restricted intermediate channel under different channel widths, water depths, and speeds. The main factors affecting the squat are analyzed, the empirical relation is compared with the measured squat. The Barrass equation is modified, and the calculation relation of the settlement suitable for inland river ships is proposed. The correlation coefficient R 2 of the modified
Long, LijiMiao, JilunZhao, WanxingHuang, Chenglin
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