The shipping industry is the primary and most significant mode of international cargo transportation. The ship must comply with strict rules regarding reducing greenhouse gas (GHG) emissions as a dominant transportation mode. Liquified Natural Gas (LNG) is the primary alternative fuel option for several shipping companies. In essence, many studies recommend LNG as a transitional and alternative fuel because its emission characteristics are cleaner than other fossil fuels. Several previous investigations have been carried out to develop an action plan for integrating the use of LNG as a ship fuel. However, there have been few discussions on the estimation of GHG emission reduction and the economic efficiency of a representative LNG-fuelled ship. The recent progress on LNG-fuelled ships is systematically reviewed to summarize the pathways and highlight the core technological concepts, technical issues, current LNG-fuelled ship applications, and future outlooks regarding integrating LNG energy resources into ship power systems to measure GHG emission reductions and cost savings estimations. The report will discuss the current development in the maritime sector and the effects of the macroeconomic scale. The result reveals that future research on ship-based LNG energy systems will probably concentrate on integrating new energy source generating strategies with existing ship power systems to improve energy efficiency. Several potential research areas for future outlook were also discussed to anticipate future challenges.
Investigation of hydrodynamic interaction between the vessel and the seabed when entering shallow water is considered one of the most critical considerations of inland waterway transport. There are many investigations into the behavior of ships in restricted waters, such as ships traveling in different forms of canal cross-sections. The present study aims to evaluate the hydrodynamic interaction of the 750 DWT Perintis Ship moving through the different canal types to determine the relative effects of limiting the width and depth cross section on the ship's resistance. Two different canals with different cross sections, including canal bank and rectangular canal, were evaluated to investigate the influence of canal width (Wb), depth ratio (hw/T), and blockage ratio function (As/Ac). The Computational Fluid Dynamic (CFD) method with Reynolds-averaged Navier–Stokes (RANS) solver and turbulent model 𝑘−𝜀 were used to predict the total resistance of the ship. The proposed numerical simulation was initially validated with an experimental towing tank test in the error range of 0.11-7.74%. The results indicated similar phenomena were found both in rectangular and canal banks. The case with a shallower (lower hw/T) and a narrower (lower Bc/Bs) canal dimension has a higher resistance value. Backflow and subsidence of free surface became significant around the ship's hull in more restricted water, changing the ship's hydrodynamic characteristics and increasing resistance. It can be found that the higher the blockage ratio (mb), the higher the total resistance value in both canal types, which proved that ships with higher speeds were more sensitive to changes in waterway restrictions.
Indonesia is the largest archipelagic country and has the potential to become the world’s maritime axis. Two-thirds of Indonesia’s territory is ocean, with a total coastline of 54,716 km. Therefore, Indonesia must have solid systems and tools to overcome the various threats in the maritime sector. One of the technologies that can be developed to protect Indonesia’s naval territory is fast patrol boats. Indonesia requires efficient patrol boats that can optimally monitor the large Indonesian sea area and various potential threats in the maritime sector. Thus, research on the hydrodynamic criteria for the hull design of patrol boats is fundamental. In this study, we aimed to evaluate the design method based on hydrodynamic characteristics to obtain the primary dimensions and shape of the ship’s hull. We designed and analysed 11 ship models in terms of the following criteria: the resistance, stability, and seakeeping performance. The 11 models included five reference models of patrol boats with varying dimensions and block coefficients between 0.42 and 0.53, three ship models with the regression method with the exact dimensions and block coefficients between 0.45 and 0.46, and three ship models with the scale method with the exact measurements and block coefficients between 0.43 and 0.45. According to the analysis results, the regression method had better total hydrodynamic criteria and greater similarity to the reference vessel. With a shorter processing time, the regression method was more efficient than the scaling method and reference ship.
1 January 2023 in Journal of Applied Engineering Science
A fast patrol boat is one of the ships intended to defend a region and rescue and search in the accident event so that the ship must have a high level of security and survivability performances. This study uses 9 design variations with various main dimensions and hull lengths to determine the effect of the different main dimensions on the hydrodynamic performances. Each criterion was affected to obtain results in hull design, durability, stability, seakeeping, floodable length, and motion sickness incidence (MSI). Simulations are carried out to determine the resistance, stability, ship response when exposed to external forces, passenger comfort, and ship safety level when a leak occurs. Resistance simulation uses a Froude number between 0 to 2.217. Stability simulation analyzes max GZ and angle of maximum GZ on seakeeping, deck wetness, and MSI simulations using 90°, 135°, and 180° wave incidence angles. The addition of bulkheads is carried out to determine the ship's response when it experiences a leak and prevents the ship's sinking when puddles enter the ship with five bulkheads per hull and three variations in distance. Design and simulation of various criteria using Maxsurf software. In the floodable length simulation, the hull added a bulkhead to determine the effect of leakage from several hull designs and watertight bulkhead spacing variations. Design 7 has the best average result compared to other designs from the simulation recapitulation results. It has a small resistance value, a large stability angle, a stable ship response when subjected to external forces, seasickness levels, and a small deck language. From the floodable length graph, it has a high flood limit that makes the ship survive and be safer than other designs. Design 7 refers to the ship Grandweld Shipyard Delivers 21M Discovery Class Vessel Fujairah Pilot.
Research on lightweight material on ship structure has taken giant steps during the last decade. One reason is that shipping activities have increased and, therefore, the possibility of increasing the carrying cargo capacity in a realistic way using advanced lightweight material. This article summarizes a research investigation regarding the experimental tests of vinyl ester bio resin material using palm oil and sesame oil based on Lloyd's Register (LR) standard. Several tests were conducted, including density, water absorption test, Fourier transformed infrared test (FTIR), scanning electron microscope (SEM), and mechanical tests to evaluate the effect of 2-10% addition of vegetable oils on mechanical properties. The influence of the addition of vegetable oils is successfully characterized using physical measurements, which indicate the possible formation of a polymer blend to increase in elongation value. Mechanical testing shows that adding vegetable oils causes a decrease in average density, hardness, bending strength, and tensile strength. The bending strength decreases about 9.20 – 47.06% for 2-10% palm oil addition and 5.33 – 42.40% for sesame oil addition. Moreover, vegetable oil causes a tensile strength decrease of about 5-18.75% on palm oil and 3.75-13.75% on sesame oil. As summarized, bio resin based on sesame oil has better mechanical behavior with the oil addition of 4-8% fulfills all Lloyd’s Register criteria.