This article describes the development of the boundary element method (BEM) to predict the partially submerged propeller (PSP) performance with and without the cup effect, and the 3D unsteady ventilation pattern under an open flow condition. The applied theory is a time-domain BEM, where the perturbation potential is a function of immersion ratio and time. For validation, the unsteady ventilating flow

The article describes research into the use of acoustic emission elastic waves (AE) for diagnosing insulated-gated bipolar transistors (IGBTs). Currently used in many modern shipboard power electronic systems, IGBTs are crucial components required to operate with extreme reliability. The acoustic emission elastic waves method was used to determine the acoustic signals of switching transistor and can

The aim of this research project was to determine the rate at which oxygen depletes in enclosed spaces. Cargo holds, chain locker and double bottom tanks are only some of the enclosed spaces found on a ship. The project was conducted using oxygen depletion experiments on scrap metal in sealed and open vented containers. In addition, the speed of oxygen depletion in a replicated chain locker is investigated

A lifting motor pump for deep-sea mining was proposed as a researching object. First, the structure and design method of this pump was introduced. Second, the simulating computations of the impeller in this pump were conducted at different working processes. Finally, the experiment of a two-stage lifting motor pump was conducted in the process of work to prove the applicability of this new lifting

Studies have been being carried out to make production faster and more organised in the shipbuilding industry, as in other industry. The fact that automation-based works are limited in the shipbuilding industry is one of the biggest challenges encountered in block production as in other stages of shipbuilding. The blocks are time-consuming and difficult components to produce in the shipbuilding process

Previously, the action factors, which are generally used in the region of Malaysia is based on the data from the Gulf of Mexico (GoM) or the North Sea, where the environmental condition is much harsher than the offshore Malaysia. Direct application of the high load factors in these regions can result in a waste of economic resources. Based on a reliability-based Load and Resistance Factor Design approach

This paper investigates the flow field around the KRISO Very Large Crude Carrier (KVLCC2) model at different drift angle using the RANS method in combination with the Re-Normalization Group (RNG) k−ε and Shear Stress Transport (SST) k−ω turbulence models. The hydrodynamic forces and yaw moment acting on the KVLCC2 model are calculated under the different turbulence models and drift angles, and the

As global warming is causing a significant reduction in the extent and the thickness of Arctic sea ice, a narrative for future large-scale commercial shipping in the Arctic has started to evolve. However, while most efforts have aimed to assess the financial benefits along with potential savings in greenhouse gas emissions, few studies have explored risk patterns and safety issues associated with Arctic

Ports are complex systems that play a crucial role in the transportation of maritime-related products and services. Since ports face various safety issues in design, installation, operation and maintenance processes, there are many aspects open for improvement in Occupational Health and Safety risk assessment and it is required to deal with risks, reduce them to an acceptable level and control. To

In the study, the dynamic analysis of the engine piston assembly was compared with the experimental measurements and the stable working speed was tried to be determined. The theoretical model was developed in addition to the experimental results. The relationships between the forces and torques applied in the crank mechanism, such as gas force and inertial force, are properly addressed. In the stationary

The current research was a comparative study of reinforced ceramic particles and mixing proportion on the microstructural and slurry erosive characteristics for fabricated composites. Dual reinforced particle composites were fabricated by adding combinations of numerous wt% of titanium carbide (TiC) and zircon sand (ZrSiO4) to aluminium die-casting (ADC12) alloy matrix composites. ADC12 alloy composite

In this paper, a single-stage, horizontal type centrifugal pump, which can be used in a chemical tanker’s cargo operations, was modelled with MATLAB/Simulink software. The modelled pump was run with seven different fluids handled in chemical tankers which are ethyl alcohol, N-Propyl alcohol, phenol, chloroform, castor oil, 55% nitric acid and water. Therefore, the pump’s performance curves and data

This paper addresses the reliability aspects regarding deck machinery on ageing/aged fishing vessels. A reliability and degradation analysis for ageing fishing vessel deck machinery enables an evaluation of the reliability trend for the remaining useful life of the deck machinery. The research was limited to the maintenance of cranes, winches and capstans and failure data for fishing vessels whose

Each vessel has its own way of sailing in the port region. Any autonomous vessel navigating such a scene should be able to predict the trajectories of surrounding ships and adjust its behaviour to avoid a collision. In this paper, combined with the sequence prediction method, a Long Short-Term Memory (LSTM) model is proposed to predict the trajectories of the vessels. The ground-truth Automatic Identification

This paper presents a methodology for the development and installation of an electric power quality monitoring system onboard a ship, for managing and optimising the electric power of critical loads that have a significant effect upon the overall ship efficiency as outlined by the International Maritime Organization rules. The improvement of overall ship efficiency is attained by installing power converters

The safe operation of marine turbine generators is a crucial concern in industries and academics. It is always important to monitor the health status of marine turbine generators. The lubricant oil usually carries abundant information on the turbine operation conditions. Various oil parameters of the turbines have been used in the existing monitoring systems. However, many of them conflict with each

Nowadays, shipping industry faces challenges of energy efficiency and reducing of fuel consumption. Moreover, Waste Heat Recovery Systems (WHRS) regarding energy efficiency have a larger focus to utilise the heat energy lost from all thermal processes from ship engines. WHRS is one of the best methods to reduce fuel consumption and implicitly emissions. Refrigeration system, which can be evaluated

As one of the most critical vessel motion, heave motion will lead to the great tension at the top end of a steel catenary riser (SCR), and can also result in the compression buckling and large bending moment in the touchdown zone (TDZ). The purpose of this study is to investigate the motion transfer rule of top-end heave excitation along catenary risers and explore the underlying correlation between

This paper presents a numerical investigation on the hydrodynamic performance of sandglass-type FPSOs with four different cross sections. In order to estimate the hydrodynamic performance and utilise the results in the design stage of FPSOs, a frequency-domain numerical simulation program, ANSYS/AQWA software package, has been used. Numerical results were compared with experimental data and good agreement

The present article compares the effectiveness of two chemical compounds to reduce the growth of biofilm adhering to the tubes of a heat exchanger-condenser refrigerated by seawater. The compounds tested in the study were: a quaternary ammonium compound (QAC) and an aliphatic amine (triethanol amina, TA). Each biocide was applied intermittently in a first shock stage and in a second stabilising stage

This paper presents mechatronic design and hierarchical locomotion control of a biomimetic robotic fish for three-dimensional swimming modes. Inspired by biological features of Lamprey, a closed loop sensory feedback Central Pattern Generator (CPG) model is adapted to hierarchical control mechanism in order to provide robust and effective biomimetic control structure. A sensory feedback mechanism plays

Subsea cables protection afforded by burying a cable [beneath the sea bed] also means that the available methods for their survey are drastically reduced. From the existing methods only electromagnetics (EM) detection can penetrate the sea bed and provide an effective means for cable localisation. However, EM waves attenuate faster in conductive media such as sea water. EM localisation is considered

This paper investigated the benefits of vibration performance of diesel generator set (D/G-set) employing a kind of novel anti-vibration structure known as an inerter-rubber vibration isolator. We designed this vibration isolator in parallel with a rubber-part and a ball-screw inerter. Based on the inerter-rubber vibration isolator, the vibration system of an existing D/G-set (5DK-20) was built, and

Pressure sensor used in marine hydrographic survey is an important device for the deep sea detection, the tsunami forecast and the marine engineering. Owing to its mature technology process and low production cost, silicon piezoresistive sensor is widely applied in the field of industrial pressure measurement. However, its temperature effect can result in non-negligible dynamic error, which cannot

India is the fourth biggest electricity consumer on the planet after the United States, China and Russia. India’s energy strategy concentrates on securing energy sources to address the issue of its developing economy. Service of New and Renewable energy has started an activity to track the advancing Tidal power administrative structure and build up an archive of data in a combined way. The reason for

Submarine piggyback pipeline is an important tool for oil and gas transport, especially, in the marginal oil field. When the scour happens in the seabed, the pipeline slides easily, which may cause the pipeline failure. The dynamic slope angle is one of the most important characteristics of the scour. In this work, the dynamic slope angles of the sandy seabed under piggyback pipelines in steady flow

Sensor data from marine engine systems can be used to detect changes in performance in near real time which may be indicative of an impending failure. Thus sensor-based condition monitoring can be important for the reliability of ship machinery systems and improve maritime safety. However, there is a need for efficient and robust algorithms to detect such changes in the data streams. In this paper

Vortex induced vibration (VIV) is of practical interest since it can result in the fatigue damage of structures, so has been a highly researched topic during the past few decades. The present study employs the unsteady Reynolds-Averaged-Navier–Stokes (URANS) equations combined with the shear-stress transport (SST) k-ω turbulence model to carry out the numerical simulation of the two-degree-of-freedom

Underwater acoustic sensor network (UASN) is an emerging technology meant for underwater explorations. In underwater communication, the acoustic signal travels a longer distance with smaller bandwidth. Characteristics of the acoustic channel and the distance between underwater sensor nodes vary with time due to the variations in the water current. This affects the channel quality as well as the topology

This paper proposes a nonlinear robust track keeping control algorithm for energy efficiency from the perspective of ship motion control, based on the great significance of the twenty-first Century Maritime Silk Road. Replacing the course error e with the sin⁡(ωe) driven by the sine function in course keeping loop to serve as the input of the controller, the simulation results tested on the ship autopilot

Among the effective solutions for the reduction of environmental pollution, the use of fuels with limited-sulphur content or bio-based fuel has been paid much attention due to their advantages. In this experimental work, the ultra-low-sulphur fuel (ULSD) was mixed with biodiesel extracted from Jatropha oil (JOB) after being processed with ultrasonic assistance. There were eight samples used for mixture

This paper presents an approach to the calculation of unbalanced fault currents in shipboard power systems based on the application of Millman’s theorem. A full analysis of the time-variant fault current produced by a synchronous generator in a typical marine power system is provided; three phase three wire for principal loads and four wire earthed neutral for hotel loads. Hand calculation results

Deep-sea hydrothermal source investigation utilising water and gas samples to characterise ocean resources requires water sampler, both large and small volume. How to preserve the original captured samples in the sampler during its lifting process to the surface remains challenging. Our research develops a piston type deep-sea pressure equaliser installed in the sampling bottle to solve the pressure

The engine rooms of ships accommodate different machinery systems that are critical to ship operations. For these critical machinery systems to continue delivering the high level of service, operators are required to select and apply the best maintenance interventions. Currently, the selection of appropriate maintenance strategies for different engine room’s machinery systems is handled in a traditional

This paper first assesses the operational uncertainties of a particular piece of equipment in a marine and offshore system based on an oil analysis technique. Trend analysis, family analysis, environmental analysis, human reliability analysis and design analysis for each criterion are aggregated using evidential reasoning (ER) and analytical hierarchy process (AHP) algorithms. Data is collected from

Suez Canal is one of the shortest navigational routes between east and west. Vessels that transit the Canal should normally save distance, time and operating cost. During the current economic recession and low fuel prices, longer shipping routes may be chosen to avoid the Canal transit fees. Harsh weather conditions may be encountered along these lengthy routes resulting in higher stresses and structural

Given a number of marine vessels treating the liquefied natural gas either as cargo or fuel, this paper examined the regulatory gaps of two different international Codes – the International Code of the Construction and Equipment of Ships Carrying Liquefied Gases in Bulk and the International Code of Safety for Ships Using Gases or Other Low-flashpoint Fuels – from the regulatory standpoint. Results

The paper describes a study on fire accidents taking place aboard container ships. In total, 39 confirmed container ship fire accidents were discovered in the period 1996-2017. An epidemiological hazard analysis disclosed four high-consequence hazardous cargos that are calcium hypochlorite, compressed charcoal briquette products, rechargeable batteries and divinylbenzene. Cause-consequence analyses

In this research, a numerical investigation on the hydrodynamic response of a semisubmersible platform, developed by DeepCwind consortium, equipped with the National Renewable Energy Laboratory 5-MW reference wind turbine, and a typical 6-MW wind turbine is conducted. The main objective is to develop a numerical model validated by experimental test results of a semisubmersible platform with mooring

In recent years, the inland river shipping industry in China has been facing the pressure to comply with ‘low carbon shipping’ policies. Solar energy as one of the most widely used new energy sources has attracted more and more attention in the shipping industry. In 2015, the researchers from Wuhan University of Technology have successfully applied solar energy in an inland river 800PCC (Pure Car Carrier) –

In this article, we discuss the effects of touchdown on an inclined seabed of a mooring system consisting of one or two chains joined at the sinker that is subjected to horizontal tension or tension at the suspension point. We modeled the statics of the system using the classical non-extensional catenary theory. For a system without a sinker, we provide an analytical solution for the governing equations

In this research, we evaluated the possibility of using hollow fibre membranes combined with a VOC recovery system to recover high-capacity of VOCs in crude oil loading conditions. We initially investigated the performance of a basic membrane module under various conditions, and then developed and tested a large-scale membrane system. The ranges of conditions were determined based on practical and

A ship is always under the influence of matched as well mismatched uncertainties and external disturbances owing to its operational environment and, therefore, designing an autopilot that offers uniform performance in the presence of uncertainties and disturbances poses a challenging task. In this work, to address the issue, control design based on adaptive backstepping robustified by Uncertainty and

Energy efficiency management is becoming increasingly important in the trend towards decarbonisation and intelligentisation of future ships. Establishing a verified energy efficiency model is essential in realising reliable assessment of various energy efficiency strategies. Based on a 53,000-tonne bulk carrier, modelling and verification of a ship’s energy efficiency with consideration of multiple

The extremely serious effects of the marine environment pollution due to oil spill, oil slick and toxic heavy metals on the human, ecosystem, and society are clearly seen. Findings of absorbent materials with high absorption capacity and high usage efficiency are being much interested by several researchers. In this work, four samples of absorbent material fabricated after adding, respectively, 5%

Installation of un-trenched marine pipelines on an uneven seafloor usually leads to many free-span formations along the pipeline. Also, offshore pipelines may be subjected to high longitudinal forces that can change pipeline behaviour in diverse loading states. In this paper, the effect of axial force on pipeline deformation at the free-span location and associated hazards are assessed. The excessive

In this paper, a risk cloud model (RCM) based on cloud model theory is proposed for evaluating risks in the nautical navigational environment (NNEt). To validate the method, the proposed strategy is applied to a risk evaluation of NNEt of the waters around the Hangzhou Bay Sea-Crossing Bridge and the results are compared with those of a conventional fuzzy theory-based evaluation approach. The results

In the process of ship autonomous navigation, the complex changes of the external environment lead to unknown statistical characteristics of star sensor measurement noise, which brings the estimation results of standard Kalman filtering divergence, and gyroscope on-line calibration cannot be effectively carried out. In view of the above problems, this paper proposed a gyroscope on-line calibration

A method for dynamics analysis of underwater vehicles is presented in this paper. The strategy consists of two stages. At the first stage, we propose an adaptive velocity tracking controller for the vehicle. The control algorithm is expressed in terms of transformed equations of motion in which the inertia matrix is diagonal. Consequently, it takes into account the dynamics of the system and it can

Biodiesel has been considering as promising fuel in the situation of ever-depleting fossil fuels and serious environment pollution. Beside clearly known advantages, high viscosity and density, and high surface tension are the acute disadvantages that need to be improved to use directly for an unmodified diesel engine. In this work, 24 samples of biodiesel–diesel fuel blends created by mixing respectively

The aim of the study is to model and investigate the wave energy converting system with piezoelectric materials numerically. In this study, computational fluid dynamics software Fluent is used for modelling numerical wave tank. The dynamic mesh technique and volume of fluid method are employed and wave maker is moved by using the user-defined function. Transient Fluent analysis is made to receive values

The physical and mechanical properties of matrix based on epoxy resin ED-20 were investigated by adding unsaturated polyester resin ENYDYNE H 68372 TAE at different concentrations. The contents of polyester resin in the epoxy one by changing its concentration in the range of q = 10–120 mas.fr. were analysed. It was experimentally determined that matrix is characterised with its maximal rates of physical

ABSTRACT The ability to quantify vital aquatic organisms in the 2–50 µm size range was compared between five different flow cytometers and several different microscopes. Counts of calibration beads, algal monocultures of different sizes as well as organisms in a Wadden Sea sample were compared. Flow cytometers and microscopes delivered different bead concentrations. These differences between the instruments

This paper proposed an inverter control scheme for wind energy system under weak grid conditions. Wind-based hybrid energy system (HES) is often having the issue of poor transients and slow dynamic response due to the unpredictable nature of the wind speed and inertia of the generator who cannot respond the changes instantly. The proposed control scheme is designed to improve the transients and dynamic