http://lib.buet.ac.bd;localhosthttp://:8080/xmlui/handle/123456789/5939 Post graduate dissertations (Theses) Naval Architecture and Marine Engineering (NAME) 2026-04-15T01:59:42Z http://lib.buet.ac.bd;localhosthttp://:8080/xmlui/handle/123456789/7224 Comparative study of scantling requirements among different classification societies for coastal vessels plying in the inland waterways of Bangladesh Mashiur Rahaman, Dr. Md.; Humayun Kabir, Md.; 0421122002; 626.81095492/HUM/2025 In Bangladesh, numerous types of transportation facilities are available, including roads, railways, inland water transport (IWT), and air flights. Among these alternatives, the inland water transport system stands out for its cost-effectiveness and environmental aspects. Coastal vessels plying in inland waterways play an important role in transporting industrial goods, passengers, and consumer-level commodities between different areas of Bangladesh, as well as neighboring countries like India and Myanmar. Due to the important role of inland water transport vessels in Bangladesh's, economy and connectivity, ensuring their structural integrity is essential for both safety and operational efficiency. The structural strength of these vessels must withstand various environmental challenges, such as fluctuating water levels, high currents, and the stress of carrying heavy loads over distances. In addition to the physical demands, these vessels must also meet international standards for structural integrity. Hence, the structural strength requirements for these vessels are of utmost importance. Classification societies establish and implement rules and regulations regarding the design, construction, and operation of vessels, thereby contributing to the overall safety of the maritime transportation system. However, it has been observed that different classification societies may impose various standards and criteria for ensuring the structural requirements of vessels operating within different geographical regions and operational conditions. In the present study, f i ve cargo vessels and four oil tankers plying on the inland waterways of Bangladesh were studied using the structural rules and regulations of six different international classification societies i.e. RINA (Registro Italiano Navale), BV (Bureau Veritas), IRS (Indian Register of Shipping), TL (Turkish Loydu), KR (Korean Register), LR (Lloyd's Register) and the DoS (Department of Shipping) in Bangladesh. The weight of the structural components has been estimated according to scantling calculations, and a comparative study has been conducted across different classification societies based on structural weight. Only the plating thickness and weight have been considered in the present study. The calculation of the dimensions of each internal structural member has been omitted. Instead, a more simplified approach has been adopted. The minimum required section modulus at midship is determined using the empirical formulas provided in classification society rulebooks. The results indicate that all classification societies yield similar outcomes, with slight variations observed in the RINA and BV classes compared to others. So, the overall trend of variation in structural weight is not affected. The study reveals that RINA and BV classi cations yield the minimum structural weight, while IRS and TL classi cations result in maximum structural weight. Then a reduction in weight is observed for KR and LR classifications, which is again followed by an increment in weight under DoS. This trend is consistent for all the ships, both cargo ships and oil tankers presently studied. Finally, an investigation has been undertaken to assess the underlying causes of variation in structural weight. The analysis reveals that geographical constraints, the selection of ship principal particulars for scantling calculations, allowance for corrosion addition and some specific coefficients and constants are possible causes behind the variation in structural requirements 2024-12-01T00:00:00Z http://lib.buet.ac.bd;localhosthttp://:8080/xmlui/handle/123456789/6586 Numerical analysis of turbulent flow around the ship hulls using star-CCM+ Tarafder, Dr. Md. Shahjada; Sarker, Doyal Kumar; 1017122003; 532.0527/SAR/2021 The analyses of turbulent flow around the ship hulls which includeWigley hull, Kriso container ship (KCS), Series 60, HSVA tanker and a catamaran hull are conducted for various Froude numbers using a commercial computational fluid dynamics (CFD) code STAR-CCM+. The finite volume method (FVM) is employed to discretize the governing equations of fluid flow and the SIMPLE (semi-implicit method for pressure linked equations) algorithm is applied to get the solution of pressure-velocity coupling equations. The k- turbulence model is chosen to give the closure to the Reynolds Averaged Navier Stokes (RANS) equations and the volume of fluid (VOF) method is applied to capture the interface between the two phases. Dynamic fluid body interaction (DFBI) module is used to simulate the motion of rigid body (ship hull) which is unconstrained to sink and trim. A trimmed cell mesher technique is used to produce hexahedral cell and prism layer mesher model is applied to resolve the turbulent flow accurately near the solid wall of the hulls. The present numerical results (wave profile, wave pattern and resistance) obtained from STAR CMM+ for each mono hull are compared with those of its available experimental results and the agreement is found to be quite satisfactory. The sinkage and trim are calculated only for Wigley and KCS hull and are compared with the experiment. The predicted wave pattern is composed of transverse and diverging waves and looks very similar to Kelvin wave pattern. Moreover, the grid dependency study is carried out for Wigley, KCS and Series 60 hulls and as expected the finer are the grids, the better is the accuracy found with a cost of longer computation time. In case of catamaran, the wave-making resistance of the catamaran hull exhibits broadly similar trends to those of the published monohull results as well as the experiment. However, the magnitude of the wave elevation of the inner side of the catamaran hull is slightly higher than that of the outer side at the first crest of the bow. This difference is mainly due to the wave-interference effects. Above all, the standard two-equation k- turbulence model with near-wall function is used to predict the turbulent flow characteristics which are very close to experimental results and could be considered as a powerful tool for analyzing the viscous fluid flow. 2021-06-06T00:00:00Z http://lib.buet.ac.bd;localhosthttp://:8080/xmlui/handle/123456789/6524 Prediction of fuel consumption and evaluation of energy efficiency of ships in Bangladesh using machine learning Awal, Dr. Zobair Ibn; Monisha, Ishrar Israil; 1018122006; 626.81095492/SH/2023 CO2 emissions from ships and their environmental effect are intensifying with the expansion of ship transportation activities worldwide including Bangladesh. Therefore, it is vital to reduce fuel consumption to facilitate energy-efficient shipping for the inland, coastal, and sea-going ships of Bangladesh. This research aims to develop the fuel consumption prediction model of sea-going ships in Bangladesh. Establishing CO2 emission inventories through quantifying the shipping emissions is another aim of this research because of the potential to comprehend the effects of the activities undertaken and the data about the current state of the relevant regions provided by emission inventories. The present study also aims to assess the ships’ operational energy efficiency based on the Energy Efficiency Operational Indicator (EEOI). The current research implements machine learning, one of the data-scienceapproaches, considering its wide range of advantages and avoiding the drawbacks of conventional approaches. Fourteen machine learning algorithms are implemented to develop models having default hyperparameters using pre-processed noon report data of fivesea-going bulk carriers of Bangladesh to predict fuel consumption. Again, from these algorithms, 12 algorithms are used through 10-fold cross-validation to develop prediction models. The Root Mean Square Error, Mean Absolute Error, and Coefficient of Determination are used as the evaluation metrics. The developed models are validated using the data of one of the five vessels. The most effective and feasible model is selected based on the evaluation metrics and validation process. CO2 emissions in cruising, maneuvering, and hoteling phasesdue to fuel consumption of the four concerned vessels are calculated. EEOI values of the three concerned vessels are determined utilizing the determined CO2 emissions.Additionally, EEOI values are recalculated for two different scenarios, such as three distinct percentages of fuel saving and fully laden conditions. The results show that the developed and finally selected model would be a suitable tool for predicting ships’ fuel consumption in Bangladesh. Moreover, CO2 emission inventories of the concerned vessels are developed and analyzed. The energy efficiency of the corresponding vessels is successfully evaluated and investigated how the energy efficiency changes at various operating conditions. However, there are discrepancies between the actual and predicted fuel consumption. Besides, emission inventories development and energy efficiency evaluation could not be accomplished for all five vessels. The reasons are the extreme difficulties of collecting data and the lackof stored voyage data of the vessels of Bangladesh. 2023-06-21T00:00:00Z http://lib.buet.ac.bd;localhosthttp://:8080/xmlui/handle/123456789/6414 Numerical modelling of a wave energy converter based on the wave climate around the Saint Martins island of Bangladesh Kumar Saha, Dr. Goutam; Das, Mohua; 1018122001; 551.52460954923/DAS/2022 Saint Martin′s Island is the only coral island and one of the well-known tourist spots in Bangladesh. Because of its geographic location, electricity cannot be supplied from the mainland through the electricity grid. Diesel generators and solar power are the only means of electricity generation presently available there. Surrounded by the sea, Saint Martin′s Island has the ideal conditions for wave energy extraction. The purpose of the study is to assess and optimize the performance of a heaving-point-absorber-wave-energy-converter in light of the existing wave climate around the island. The power generation performance of a cylindrical buoy shape has been tested for a variety of diameters and drafts. The mass properties of the selected design have been determined using simple structural analysis, and the hydrodynamic coefficients have been calculated through modelling and simulation in frequency-domain. Using the hydrodynamic coefficients data obtained from frequency-domain analysis, the response as well as power output of the system have been estimated using time-domain analysis with linear power take-off system. Comparing the power performance of different draft diameter combinations of cylindrical buoy, the best design with maximum power output per unit buoy weight have been selected. Moreover, two other buoy shapes are tested, the values of surface area and volume obtained from optimal cylindrical configurations are used to generate new buoy profiles. Finally, comparing the results of power performance simulations, a discussion on the behaviors of different buoy shapes in different months have been presented and most suitable buoy shape for the intended energy deployment site have been proposed. Moreover, the key areas that requires further investigation have been identified and discussed. 2022-05-28T00:00:00Z