Browse Topic: Marine vehicles and equipment

Items (1,187)
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
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
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
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
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
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
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
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
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
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
In recent years, multiple three-phase machines have become increasingly popular due to their reliability and fault tolerance, especially in the propulsion systems of ships, aircraft and vehicles. These systems greatly benefit from the robustness and efficiency offered by such machines. However, a notable challenge for these machines is that harmonics increase with the number of phases, which affects control accuracy and triggers torque oscillations. The phase shift angles between winding sets are one of the most important causes of stator current and torque harmonics. Most of conventional approaches for studying triple-three-phase or nine-phase machines focus on specific phase shifts and lack a comprehensive analysis over a range of phase shifts. This paper discusses the current and torque harmonics of triple three-phase permanent magnet synchronous machines (TTP-PMSM) with different phase shifts. The aim of this paper is to analyse and compare the effect of different phase shifts on
Li, YuShi, BufanAndert, Jakob
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
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
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
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.
null, null
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
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.
This document defines a set of standard application layer interfaces called JAUS Mobility Services. JAUS Services provide the means for software entities in an unmanned system or system of unmanned systems to communicate and coordinate their activities. The Mobility Services represent the vehicle platform-independent capabilities commonly found across all domains and types of unmanned systems (referred to as UxVs). At present, over 15 services are defined in this document many of which were updated in this revision to support Unmanned Underwater Vehicles (UUVs). Some examples include: Pose Sensors: Determine the instantaneous position and orientation of a platform in global or local coordinates Velocity State Sensor: Determines the instantaneous velocity of a platform Acceleration State Sensor: Determines the instantaneous acceleration of a platform Primitive Driver: Performs basic mobility for a platform based on force/torque efforts Vector Drivers: Perform closed loop mobility for
AS-4JAUS Joint Architecture for Unmanned Systems Committee
Yanmar has announced that its marine subsidiary, Yanmar Holdings, is now offering a marine-grade hydrogen fuel cell propulsion system. According to the company's announcement of the system's availability, the system is suited for use in various oceangoing vessels including passenger ships, work ships, and cargo ships operating in coastal areas where hydrogen refueling is relatively accessible. Yanmar states that due to the International Maritime Organization's (IMO) revised target of achieving zero net greenhouse gas (GHG) emissions by 2050, the marine propulsion industry is robustly pursuing all decarbonization efforts.
Wolfe, Matt
To understand the effect of discharge frequency and discharge energy of dielectric barrier discharges (DBD) on the flame kernel development process, the observation of the discharges and ignition trials were performed in a constant volume vessel. Results showed that the energy of DBD released during a single cycle of discharge decreases, but the power of the discharges increases with the frequency increases. The ignition probability improved and the time for the flame propagation decreased under high frequency because the power of the discharges efficiently rises the local gas temperature near the electrodes.
AGRAWAL, SaurabhYAMAMOTO, ShuyaHORIBE, NaotoHAYASHI,, JunKAWANABE, Hiroshi
As an efficient hydrogen carrier, ammonia itself is also a promising zero-carbon fuel that is drawing more and more attention. As the combustion of pure ammonia is hard to achieve on SI engines, in this study, spark- ignited micro-gasoline-jet was utilized to ignite the premixed ammonia/air mixture in a constant volume combustible vessel at different premixed ammonia/air excess air coefficient and backpressure (represented by ammonia partial pressure). The flame image was captured by a high-speed camera and the transient pressure change in the vessel was measured by an engine cylinder pressure sensor. The experimental results at stoichiometric equivalence ratio show that the IDT (from 129.9-198.6ms to 58.7-72.6ms) and the main combustion durations (from 494.3-654.9ms to 164.7-286.2ms) of ammonia combustion are significantly shortened by the novel ignition method compared with the traditional spark ignition method, and the results of representative heat release rate and representative
Yu, WangchaoLi, MinglongLong, QuanQin, XiongjieDong, GuangyuHu, ZongjieLi, LiguangQian, JinLi, Yao
This study is performed to experimentally examine the effects of hydrogen addition and turbulence on the ignition and the flame-kernel development characteristics in isotropic and homogeneous turbulence for methane or propane mixtures. First, in order to investigate the ignition and flame-kernel development in quiescence, the minimum ignition energy MIE and the relationship between the flame radius and the burning velocity of meso-scale laminar flames are examined by using sequential schlieren photography in a constant volume vessel. Then, the properties of MIE are examined for three turbulence level. Additionally, the transition region of MIE could be summarized by using the proposed turbulent Karlovitz number based on the burning velocity of the meso-scale flame in quiescence.
Nakahara, MasayaMatsushita, YukiKishiura, KensukeAbe, FumiakiTokunaga, Kenichi
This SAE Aerospace Standard (AS) defines a set of standard application layer interfaces called JAUS UMV Services. JAUS Services provide the means for software entities in an unmanned system or system of unmanned systems to communicate and coordinate their activities. The UMV Services represent the platform-specific capabilities commonly found in UMVs and augment the Mobility Service Set (refer to AS6009) which is platform-agnostic. At present, 12 services are defined in this document. While these services are presented alphabetically within this document, they also can be logically categorized as: Platform Description Services: This service provides information about the vehicle platform, including mobility limits and geometric properties: ○ Platform Specification Service. Propulsion and Driver Services: These services provide the control and monitoring capabilities to the vehicle’s propulsion system(s). These services can be applied selectively to facilitate primitive mobility
AS-4JAUS Joint Architecture for Unmanned Systems Committee
An extensive evaluation of the Deep Image Prior (DIP) technique for image inpainting on Synthetic Aperture Radar (SAR) images. Air Force Research Laboratory, Wright Patterson Air Force Base, OH Synthetic Aperture Radar (SAR) images are a powerful tool for studying the Earth's surface. They are radar signals generated by an imaging system mounted on a platform such as an aircraft or satellite. As the platform moves, the system emits sequentially high-power electromagnetic waves through its antenna. The waves are then reflected by the Earth's surface, re-captured by the antenna, and finally processed to create detailed images of the terrain below. SAR images are employed in a wide variety of applications. Indeed, as the waves hit different objects, their phase and amplitude are modified according to the objects' characteristics (e.g., permittivity, roughness, geometry, etc.). The collected signal provides highly detailed information about the shape and elevation of the Earth's surface
In the shipbuilding industry, the employment of hybrid propulsion systems is increasingly common on-board vessels for making more eco-sustainable boat traffic in marine waters. Energy management systems are required to ensure the culling of fuel consumption and the preservation of batteries by monitoring their state of charge in hybrid powertrains, coupled with the possibility of performing the sea path desired by a driver unit. A Model Predictive Control (MPC) supervisor is proposed in the present work for managing a marine parallel-hybrid propulsion system in terms of handling the state of charge of batteries and the driving cycle imposed by the boat driver. Specifically, the MPC is employed to avoid excessive electric energy consumption observable as a reduced loss in terms of the state of charge of batteries by selecting the best amount of command torques related to two electric motors and one internal combustion engine of the considered powertrain. A lumped parameters model of a
Tordela, CiroFornaro, Enrico
The transportation industry has been scrutinized for its contribution towards the global greenhouse gas emissions over the years. While the automotive sector has been regulated by strict emission legislation globally, the emissions from marine transportation have been largely neglected. However, during the past decade, the international maritime organization focused on ways to lower the emission intensity of the marine sector by introducing several legislations. This sets limits on the emissions of different oxides of carbon, nitrogen and sulphur, which are emitted in large amounts from heavy fuel oil (HFO) combustion (the primary fuel for the marine sector). A 40% and 70% reduction per transport work compared to the levels of 2008 is set as target for CO2 emission for 2030 and 2050, respectively. To meet these targets, commonly, methanol, as a low-carbon fuel, and ammonia, as a zero-carbon fuel, are considered. But for the well-being of the marine ecosystem, nitrogen and sulphur
Tripathi, ShashwatGorbatenko, InnaGarcia, AntonioSarathy, Mani
Non-Road Mobile Machinery (NRMM) incorporates a wide variety of machines not intended for the transport of passengers or goods on the road. This includes small gardening equipment, construction, mining, agricultural, and forestry machinery up to locomotives and inland waterway vessels, mostly using an internal combustion engine. NRMM was often overlooked and neglected in the past when considering pollutant and greenhouse gas emissions. Due to their high diversity, they are hard to categorize, resulting in a lack of available data. As emissions from road transport are being tackled by regulations, the emissions of NRMM become an increasing part of total transport emissions. An alternative to fossil fuels will be required for the energy supply of NRMM to fully commit to the CO2 reduction goals, and to fulfil the future requirements of legislators and public opinion. This study provides a report on the energy needs of different applications, mainly focusing on the larger machinery, as
Dejaegere, QuintenVerhelst, Sebastian
This paper presents experimental and simulation studies on a hydrogen fuel cell that utilizes hydrogen and oxygen as reactants, making it suitable for specific vehicles such as submarines and underwater vehicles with air-independent propulsion systems. A fuel cell prototype with an active area of 25 cm2 was constructed using commercial materials and analyzed in detail. The experimental data were compared to numerical results obtained by the ANSYS PEM Fuel Cell Module, and the two sets of results were found to agree closely across a range of polarization curve observations corresponding to voltages between 0.93 and 0.29 V. The validated numerical model enables exploration of internal phenomena, such as mass fractions, water contents, and current flux density that are difficult to study through experiments. This model can also aid in optimizing the configurations and characteristics of the fuel cell components. The findings indicate the potential of using hydrogen fuel cells in specific
Ha Hiep, NguyenQuoc Quan, NguyenHong Thai, GiangThi San, Pham
This SAE Recommended Practice establishes uniform requirements and guidelines for the display of capacity information of personal watercraft.
Personal Watercraft Committee
After decades of tantalizing breakthroughs in battery technology, the last decade witnessed the emergence of energy storage as a challenger to fossil fuels for powering vehicles. We are now in the midst of a once-in-a-lifetime opportunity to change the energy landscape and electrify all forms of transportation: light duty passenger cars, heavy duty commercial vehicles, as well as various forms of transportation such as trains, ships, and aircraft.
BAE Systems, Inc. Arlington, VA 571-488-0456
Aurora Flight Sciences, a Boeing Company Manassas, VA 703-369-3633
Winds racing across the North Sea often wreak havoc among vessels in the 600-mile waterway. While its many islands and sandy beaches make it a popular vacation spot, the North Sea is often rough and stormy. In April, nine nations signed a pact to expand wind farms in the North Sea by eight times from its current level.
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