Master Dissertations

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A Study in Friction Stir Welding on Marine Grade Dissimilar Metals
(Indian Maritime University, Kolkata Campus, 2024) C, Harshit; Chakraborty, Sadananda
Friction Stir Welding is an advanced technique for joining dissimilar materials, mitigating traditional welding issues like solidification cracking and distortion. This study explores friction stir welding for marine-grade Aluminium Alloy 6063-T4 (AL6063-T4) and Magnesium Alloy AZ31B (MG AZ31B), highlighting their lightweight and corrosion-resistant properties suitable for marine environments. Chapter 1 provides a comprehensive background, goals, and benefits of the study. It includes detailed analyses of relevant journal articles and modifications of general articles pertinent to this project. To improve both the weld quality and the efficiency of the friction stir welding process. Chapter 2 goes into detail about Tool geometry which is critically examined to enhance weld quality and friction stir welding efficiency. Steady-state temperature analysis identifies the optimal tool shape using "SolidWorks" for superior mechanical and thermal performance. The tool assembly includes a high-speed steel (HSS) drill bit and an H13 tool steel shoulder. In Chapter 3 a custom vertical milling machine welds two alloy plates, modelled independently in ANSYS for thermal analysis. The study uses SOLID70 elements for three dimensional thermal analysis, with precise boundary conditions to ensure accurate predictions. A tetrahedral mesh captures high-temperature gradients and stress concentrations, providing insights into deformation, stresses, temperature, and welding properties. In Chapter 4, AL 6063-T4 and MG AZ31B alloys are joined using friction stir welding, with specific surface preparation and butt joint configurations. Mechanical testing includes Vickers microhardness and tensile tests, revealing variations in joint hardness and intricate stress-strain behaviours. Failure analysis identifies TMAZ as the primary failure site, emphasizing its diverse texture structures and fracture initiation. Chapter 5 focuses on optimizing hardness and tensile strength through experimental and Computational Fluid Dynamics (CFD) analysis. ANOVA assesses the impact of rotational and travel speeds on tensile strength, finding rotational speed significantly influences tensile strength. Verification runs confirm the effectiveness of optimized parameters, with minor discrepancies suggesting areas for CFD model improvement. Lastly, friction stirs welding successfully welds 6063 T4 and AZ31B alloys at 430–490°C, enhancing microhardness and joint integrity. While joint tensile strength is lower than base materials, optimization at 1120 rpm and 63 mm/min improves yield strength. Future research should explore microstructural analysis, material innovation, application-specific studies, environmental impact, and standardization, underscoring friction stir welding's potential across various sectors.
Analysis of thermal behaviour of a microprocessor using simulation and experiment
(Indian Maritime University, Kolkata Campus, 2023-07) M, Naveen; Das, Nachiketa; Mondal, Sabyasachi; Mishra, Deepak
Thermal management of microprocessor is considered as an important factor in computer appliances. Several analysis and methods have been discussed regarding the scope of heat sink and microprocessor. The shape, size, material of heat sink and velocity and direction of air from the CPU fan plays an important role for thermal management of microprocessor while running the CPU. In this research a numerical and experimental analysis is done for the heat sink and microprocessor in order to understand the thermal response. Numerical analysis is done using software ANSYS 2023 STUDENT R1 version and an infrared thermographic study has been done as part of experimental analysis on the CPU model HP COMPAQ ELITE 8300 SFF. Microprocessor used in this experiment is Intel core i7 chips and exact dimension of CPU chassis have been taken for the numerical part. The thermal images are captured with Fluke Ti 450 camera. The device offers high spectral resolution while taking the thermal image. Analysis shows there are small deviations between the numerical and experimental part. Using nanofluids, a method is also been discussed for thermal management of microprocessor as a substitute for heat sink, for future scope of the project.
Biochar Reinforcement in Epoxy Composites for Enhanced Mechanical Properties and Fire Resistance
(Indian Maritime University, Kolkata Campus, 2025) K, Vishnu Anilkumar
In response to the growing need for environmentally sustainable and high-performance composite materials, this study explores the use of bamboo-derived biochar as a reinforcing filler in epoxy resin composites. Bamboo was selected due to its rapid renewability, abundant availability, and high lignocellulosic content, making it a viable precursor for biochar production through pyrolysis. Biochar was synthesized via slow pyrolysis at 500°C and integrated into epoxy resin at varying weight percentages (1%, 3%, and 5%) to evaluate its impact on mechanical, thermal, and fire-retardant properties. The fabricated composites were subjected to tensile testing, where the 5 wt% biochar-reinforced composite exhibited the highest performance, achieving an ultimate tensile strength (UTS) of 47.90 MPa, compared to 28.00 MPa in the neat epoxy. Young’s modulus increased from 1.85 GPa (0% biochar) to 2.42 GPa (5% biochar), indicating a significant enhancement in stiffness. Elongation at break showed a marginal decrease with increasing filler content, highlighting the typical trade-off between strength and ductility. Thermogravimetric Analysis (TGA) demonstrated improved thermal stability in composites containing biochar. The 5 wt% biochar sample showed a higher decomposition onset temperature and a residual mass of 38% at 800°C, compared to only 0.6% in the control sample. This indicates strong thermal barrier effects due to char formation. Although direct cone calorimetry testing could not be performed, a detailed review of similar studies and comparative interpretation with TGA data suggested improved flame retardancy with increased biochar content. Key inferred outcomes included longer time to ignition, reduced peak heat release rate (PHRR), and higher char residue, particularly in the 5 wt% composite. This investigation validates the multifunctional role of bamboo biochar in enhancing tensile strength, thermal stability, and flame-retardant behavior of epoxy composites. The findings support the use of such bio-based reinforcements in marine structural components, interior panels, and thermally sensitive applications. Moreover, this work opens future directions in optimizing pyrolysis conditions, scaling fabrication processes, and validating long-term durability and fire performance in real-world environments.
CFD analysis of marine propeller using duct and testing thrust performance over various duct configurations
(Indian Maritime University, Kolkata Campus, 2022-11) Chakraborty, Kartik; Chakraborty, Sadananda
Condition Monitoring of Lubricating Oil used in Marine Vessels
(Indian Maritime University, Kolkata Campus, 2025) Kumar, Ajay; Mishra, Deepak
The reliability and efficiency of marine propulsion systems heavily depend on the condition of lubricating oil, which serves as both a protective and functional medium for critical engine components. Over time, lubricating oil undergoes degradation due to thermal stress, oxidative reactions, contamination, and prolonged usage. Traditional oil condition monitoring techniques primarily focus on viscosity changes, spectroscopic analysis, and chemical composition assessments. However, in recent years, polarization current analysis has emerged as a promising diagnostic tool for evaluating the dielectric integrity and degradation behaviour of lubricating oils in marine applications. This study explores the application of polarization current measurement as an effective method for monitoring the deterioration of lubricating oil used in marine vessels. The research involves subjecting lubricating oil samples to controlled thermal aging at varying temperatures (40°C, 50°C, 60°C) over extended periods to simulate real operational stress conditions. By applying a 500 V DC voltage using an insulation tester, the resulting polarization current behaviour is recorded and analyse providing valuable insights into molecular breakdown and insulation capacity loss. Experimental findings indicate that as the thermal aging process progresses, the polarization current exhibits increasing magnitudes, signifying a reduction in the resistivity of the lubricating oil. This behaviour aligns with the formation of conductive degradation byproducts such as free radicals, oxidation compounds and polar contaminants, which alter the dielectric properties of the oil. Notably, samples exposed to higher temperatures (50°C and above) demonstrate significant fluctuations in polarization current, suggesting a higher degree of dielectric instability and lubricant deterioration.
Design of plate fin heat exchanger with offset strip fins for the liquefaction of natural gases
(Indian Maritime University, Kolkata Campus, 2019-06-20) Kashiwal, Mukul; Eswara, Arun Kishore
In the cryogenic systems such as liquefier, cryo-coolers, etc. the heat exchangers are one of the most critical components. The heat exchanger used in cryogenic applications must have high effectiveness to produce a proper refrigerating effect and it should not be less than 85%. It has already experimented that if the value of the effectiveness of the heat exchangers falls below the design value, then the no liquid will be produced. On a general basis, there are so many heat exchangers available in the industry which are used in the cryogenic works but there is a special category of the heat exchangers that are available, which are now used widely because of there because of their compactness, low weight, and high effectiveness. These heat exchangers are known as the compact heat exchangers. The objective of this work is to design a plate fin heat exchanger, which is when used in the liquefaction cycle must be able to liquefy the natural gases and to produce 1000 Kg liquid ih a day, which can be transported easily for the various purposes through various ways. This work has been carried on the plate fin heat exchanger with selecting the offset strip fin, which is the most reliable fin design in the liquefaction applications. The work includes the two cryogenic fluids, one is methane and the other is propane. Propane is used as the coolant to bring down the temperature of methane to this close that when passed through the expander or by precooling in the liquefaction cycle it gets liquefied easily. Catia software was used to model the component and Matlab programming has also been done to design a plate fin heat exchanger. As the geometry were too complex to analyse in the software because of the physical memory limitation, a small symmetric part of the heat exchanger model were imported in the analysis software called Ansys 18.1 for the validation of the results and it can be concluded from the observations that the model is capable to do the desired function. A small variation in the calculation and analysis results has been observed, and the effectiveness of the heat exchanger was found to be above 90 %. Aluminium 3003 has been used as the material for the fins strips and for separating plate.
Design of small scale liquefaction cycle for natural gas
(Indian Maritime University, Kolkata Campus, 2019-06-19) Gupta, Nishit; Eswara, Arun Kishore
Liquefied natural gas is found to be the most economical mode of transportation for distances covering more than 3500 miles. The boiling point of natural gas is 111 .7 K at atmospheric pressure and falls under the category of cryogenics. The process has components such as compressor, heat exchanger, expansion valve, insulating material, storage tank and pipes. The liquefaction of natural gas is achieved by processing natural gas in the liquefaction cycle. There are many parameters affecting the cycle such as compressor efficiency, heat exchanger effectiveness, ambient temperature, friction losses in pipes and insulating materials. In this thesis, some of the above mentioned parameters are considered while some parameters are neglected or assumed appropriately. It is observed that out of the existing cycles such as simple Linde-Hampson cycle, Pre-cooled cycle, Claude cycle and Kapitza cycle, each cycle has its own benefits and drawbacks. The fraction of liquefaction is found maximum for simple Claude cycle while the work required also reduces due to expansion of the high pressure gas through reciprocating expansion engine. The iterative procedure to find the configuration of each cycle is explained in the thesis and can be used with minimum bare inputs. An experimental setup can be built through these configurations and better study can be performed. To obtain the results, residue in the iterations is taken to 0.1 for temperature, pressure and mass flow rate both. In the Claude cycle, for mass flow rate of 1.02 kg/sec and the pressure ratio of 40, the fraction of liquefaction is found 0.0646 while in the kapitza cycle, for mass flow rate of 1.35kg/sec and the pressure ratio of 40, the fraction of liquefaction is found as 0.040. It is found that, the pressure required to liquefy the gas is not practical in the case of Linde-Hampson cycle. Further, it is found that Claude and Kapitza cycle can be used for experimental purpose.
Effect of internal load and temperature on graded spherical shell
(Indian Maritime University, Kolkata Campus, 2023) Balmiki, Sanjay; Saha, Sujoy
In this work, the effect of internal pressure in a functionally graded hollow spherical shell is theoretically studied. The material properties through the graded direction are assumed to be non-linear with power law distribution. In order to obtain the effect of internal pressure and temperature on the design of pressure vessel, Navier and heat conduction equations are solved by direct method. The pressure variation and the mechanical stress distribution such as radial stress distribution and hoop stress distribution along the radial direction are presented in a sequential manner. The radial distribution of temperature has also been depicted in the result and discussion section. As a result of which it may be concluded that the material which has lower power law index is beneficial in terms of generation of lower thermal stress. The study also aims to understand the influence of autofrettage on stress distribution and load bearing capacity in thick spherical shells. Analytical equations, based on the Maximum Shear Stress theory and Distortion Energy theory, are derived to determine the optimum radius of the elastic-plastic juncture, known as 𝐶𝑜𝑝𝑡 in autofrettage technology. The results demonstrate that autofrettage increases the pressure inside the shell, enhancing its ability to withstand higher internal pressures.
Effect on number of blade on the performance of the vertical axis marine current turbine
(Indian Maritime University, Kolkata Campus, 2022-08) Mohanty, Debashis; Sarkar, B. N.
Experimental analysis of drag forces on a floating model under varying submergence conditions
(Indian Maritime University, Kolkata Campus, 2022-08) Gnanadevan, R.; Mitra, Kalyan; Deogade, R. B.
When a floating body is towed against a stream of water it experiences drag as a result of the resistance provided by the water. An object’s resistance to motion is made up of air and water drag. Analysis of drag force is necessary to determine the hydrodynamic forces acting on the object which is required for the selection of a propulsion system. The physical model test is one of the most accurate methods because it derives the common solution by taking into account the performance of all parameters. Model alteration, Fabrication and actual experimental testing in a water are part of traditional model testing. Based on the solutions of the model tests, alterations are made to the design of the floating body and experiments are repeated until required results are obtained. Drag force measurement experiments are generally conducted on still water conditions i.e. on a floating platform carrying dead weight or with container of liquid. The present model experiments are conducted under still and monochromatic wave conditions at different rating trolley velocities and the solutions are evaluated for the difference of drag force on floating platform with dead weight and liquid at above and below the centre of gravity of the boat. The experiments will help in analysing impact of the drag force due to the effect of shift in centre of gravity in liquid when partly filled with the same dead weight load on the floating body. This analysis will help in identifying the safety precautionary standards in case of emergency situations due to free surface effects especially for Roll on and Roll off (RO/RO) and multi cargo carriers.
Experimental Study of SMAW on DSS 2205 and SS 316L for Marine Applications
(Indian Maritime University, Kolkata Campus, 2024) Kumar, Ritesh; Kumar, Dhiraj
Maritime-grade stainless steel, such as Duplex 2205 and 316L, is widely utilized in shipbuilding constructions, cargo tanks, offshore oil rig platforms, and many other maritime sectors. Austenitic and duplex stainless steels are also widely used in a variety of manufacturing industries and other domains. Because of its unique structural combination of ferrite and austenite grains, it has various benefits like high strength, excellent toughness, and resistance to pitting, crevice corrosion, and stress corrosion cracking. In the present study, shielded metal arc welding is used to weld two dissimilar materials DSS 2205 and SS 316L of dimension 60 mm x 60 mm x 2 mm. Two different types of electrodes such as ER2209 and E316L-16 is used to perform the welding, and also the current are varied from 80A to 100A at constant voltages of 24V to investigate the weld quality characteristics. A detailed investigation was conducted into the effects of electrodes and current on the mechanical characteristics and microstructure of welded specimens. Furthermore, the weld deposition has been investigated by weighing the welded sample before and after welding. The results shows that weld deposition initially increases with an increase of welding current from up to 90A, and then it declines from 90 to 100A. Moreover, transient thermal analysis based on FEM is performed by using ANSYS software, and simulated temperature of weld zone is obtained. Infrared thermal imager is used to capture the actual temperature of weld zone. The actual temperature obtained from thermal imager also validates the simulated temperature. Based on micrograph, martensite and austenite formation has been observed in the duplex stainless steel region and ferrite and cementite has been observed in 316L stainless steel region. This thesis is divided into six chapters. The first chapter provides an overview of steel welding and its applications across various fields, with a focus on the distinguishing features of SMAW welded samples of DSS 2205 and 316L stainless steel. Chapter 2 reviews the literature on various stainless steel processing techniques and the properties of DSS 2205 and 316L stainless steel, including microstructural, mechanical, and thermal analyses using the Ansys software, and their applications. Then, it identifies gaps in the existing literature and sets targets for addressing problem identification. Chapter 3 details the materials and procedures used in this study and discusses the various characterization strategies employed. Chapter 4 presents the results and discussion of SMAW welded DSS 2205 and 316L stainless steel, including an in depth investigation into how changes in current and electrodes affect the mechanical properties of these materials. Additionally, this chapter uses the Ansys software tool to study temperature distribution and heat flux during the welding of DSS 2205 and 316L stainless steel. Finally, viii Chapter 5 provides a comprehensive summary of the study, along with an exploration of the future scope and additional possibilities for ongoing research on SMAW welded DSS 2205 and 316L stainless steel.
Microstructural, mechanical, and thermal analysis of SS316L weldment for marine engineering application
(2023-07) Kumar, Aswin S.; Shukla, Amarish Kumar
A SS316L steel is known as a marine-grade material, which is frequently used in a shipbuilding structure and marine industries. In the present study, a shielded metal arc welding (SMAW) process was used for similar welding of SS316L steel plate with dimension of 60 mm x 60 mm x 2 mm. A two different electrode E316L-16 and E308L-16, welding currents of 70 A, 80 A and 90 A and constant voltages of 24 V has been used for weldment. The impact of electrodes and current on the microstructure and mechanical properties of welded specimens was thoroughly investigated. To evaluate the flaw in the fusion zone (FZ), a surface macrograph and microstructure were analysed using scanning electron microscopy (SEM). In order to study the surface characteristics and ascertain the elemental composition of the samples, energy dispersive spectroscopy (EDS) was used. The hardness tests have been carried out in the base, heat-affected zone, and fusion zone of the welded joint. Tensile tests were carried out to study the effect of heat input on the yield strength (Y.S), Ultimate tensile strength (UTS) and elongation of a welded sample. According to the microstructure results, as the heat input increases, the grain structure of the welded zone gets finer in comparison to the base material. A hardness and tensile result shows that the properties of electrode and applied current has an effect on the mechanical properties of the SMAW welded sample. The hardness of the fusion zone increases compared to base material. The hardness result shows that as the current increases from70 A to 80 A by using the electrode of E316L-16 the hardness increases from 214 HV to 223 HV while the hardness further decreases to 208 HV for 90 A. Similarly, for E308L-16 electrode the hardness increases from 190 HV to 218 HV, and further it decreases to 168 HV for the applying current of 70A, 80A and 90 A respectively. A tensile result shows that the UTS of the SMAW welded sample varies from 190 to 262 N/mm2 compared to base material, i.e., 565 N/mm2Furthermore, thermal analysis was performed using ANSYS software to look at the impact of heat input at various welding arc times and identify the temperature distribution on the plate across various regions. In addition, the effect of heat input on the microstructure behaviour were studied in detail. The current thesis has been broken into six chapters. The first chapter presents an overview of steel welding and its applications in numerous fields. It also emphasises the distinguishing feature of the SMAW welded 316L stainless steel. Chapter 2 discusses the literature on various stainless steel processing processes, as well as the reported literature on the properties of 316L ix stainless steel, such as microstructural, mechanical, and thermal analysis of steel using the ANSYS software tool, and their applications. This is followed by identifying gaps in the literature and developing targets for addressing the issues related with SMAW welded 316L stainless steel. The materials and procedures employed in the current study are described in Chapter 3. Furthermore, this chapter discusses the various characterization strategies used in the current work. SMAW welded 316L stainless steel results and discussion in Chapter 4. A detailed investigation on the influence of changing current and electrodes on the microstructure and mechanical properties of SMAW welded 316L stainless steel was also conducted. Furthermore, the ANSYS software tool was used to study the temperature distribution during the SMAW welded 316L stainless steel. The study's summary and results are detailed in Chapter 5. Finally, in Chapter 6, the future scope and additional possibilities of current research work on SMAW welded 316L stainless steel were thoroughly examined.
Numerical analysis of flow characteristics of a fluid flowing through an orifice in a marine piping system
(Indian Maritime University, Kolkata Campus, 2024) Maji, Avijit; Saha, Sujay
Over the last few decades expensive research work has been performed by many researchers on the monitoring of rate of fluid flow through various pipes. Moreover, in the marine industry, it's important to conduct a detailed analysis of the uncertainties associated with flow measurement. It has been also seen that the coefficients, which are used for orifices are based on empirical data. Therefore, accurately predicting the impact of complex geometry and flow separation from the orifice in the flow have become crucial challenges for many researchers. From the review of the literature, it has been noted that a systematic detailed investigation of the flow through the orifice has not been done so far. Thus, in the present study a systematic details numerical investigation has been conducted for incompressible turbulent flow of water through a square edge orifice plate with considering various Reynolds numbers ranging from 153 to 273 and Bita ratios from 0.3432 to 0.6289. The standard design of ISO 5167-2 has been used in the present investigation. In this work, the simulations have been performed by using the ANSYS Fluent. The standard k-ε model has been selected for the turbulence flow analysis. The streamline contour, velocity contour, pressure contour, centreline axial velocity, wall pressure, radial profile of turbulent kinetic energy, and turbulent dissipation rate are presented in the results and discussion section in a systematic manner. From the analysis, it has been noted that the pressure drops from the orifice plate up to the vena contracta increase with increasing the Reynolds numbers and the beta ratio. It has also been observed that the pressure affects the jet-like flow in the core region, the recirculation zone, the reattachment, and the shear regions on the downstream side of the orifice. The location of vena contracta is also be estimated from present CFD simulations. Thus, this analysis improves the accuracy of coefficients. Consequently, error may be minimized in view of monitoring the rate of fluid flow in marine systems.
Numerical design on annular dump combustor of a ship
(Indian Maritime University, Kolkata Campus, 2022-08) Soni, Vaibhav; Saha, Sujoy
Numerical study on the seakeeping performances of KCS hull using strip theory
(Indian Maritime University, Kolkata Campus, 2022-08) Bhatia, Mohammed; Das, Nachiketa; Dutta, Prasun
Optimizing ship resistance by modifying hull vane geometry using CFD simulation
(2023-07) Ubhare, Rajat C.; Chakraborty, Sadananda
This study focuses on optimizing ship resistance by modifying the geometry of a Hull vane using Computational Fluid Dynamics (CFD) simulations. The resistance reduction potential of various Hull vane designs is investigated by comparing the results obtained from the simulations. The study employs CFD techniques to analyse different Hull vane geometries flow characteristics and resistance. Parameters such as maximum camber and thickness are systematically varied to determine their influence on ship resistance. The simulation results demonstrate that specific modifications to the Hull vane geometry can significantly reduce ship resistance, leading to improved fuel efficiency and speed performance. The findings highlight the importance of considering geometric parameters in the design of Hull vanes for minimizing resistance and optimizing ship performance. The presented results offer valuable insights into the potential benefits of using CFD simulations to optimize ship resistance through Hull vane geometry modifications, providing guidance for future design and optimization studies in the maritime industry. In this work, the effect of changing the geometry of the Hull vane on ship resistance will be investigated using CFD software. This study will explore how modifications to the Hull vane geometry could further enhance this device's resistance-reducing capabilities and contribute to improved ship performance and efficiency. Validation is conducted as well and presented in the section below to authenticate the current work.
Performance Assessment of Mechanical and Corrosion Behavior of Additive Manufactured PLA Structure for Marine Application
(Indian Maritime University, Kolkata Campus, 2025) V, Vishnu N; Kumar, Dhiraj; Shukla, Amarish Kumar
Additive Manufacturing (AM) finds its applications in shipbuilding sector due to its potential to produce lightweight, customizable components and on-demand components. In the current study, PLA specimens have been fabricated using FDM based on a Design of Experiments approach. In this regard, in the current paper, the experimental study, mathematical modeling and the optimization of the PLA 3D printed structure has been discussed. The input process parameters investigated are layer thickness (LT), printing speed (PS), and infill density (ID) and the response is the ultimate tensile strength (UTS) and the specific strength. Print orientation for all specimens was horizontal with a grid infill pattern. Systematic experiments and analysis are carried out to build up the mathematical equations and explore the effect of the process parameters on the responses. Besides mechanical characterization, the corrosion performance of the 3D-printed PLA specimens was analysed in a 3.5 wt. % NaCl solution to assess their suitability for marine applications. Artificial intelligence teaching learning-based optimization (TLBO) algorithm, particle swarm optimization (PSO) algorithm and desirability function analysis (DFA) based optimization technique is used to enhance the mechanical property and response as per the requirement. Of which the TLBO showed higher precision and better global optima convergence, such as the maximum UTS (51.02 MPa) and specific strength (41.6 kNm/kg). In comparison, PSO and DFA yielded slightly lower performance. Corrosion analysis showed that samples printed with higher infill densities resulted in improved corrosion resistances and so a clear relationship between print parameters and degradation behaviour was clearly demonstrated. The work highlights the significance of the process parameter choice for the enhancement of the structure and the environmental behavior of the PLA components.
Piping design for LNG liquefaction systems
(Indian Maritime University, Kolkata Campus, 2019-06-20) Gupta, Satya Vart
Liquefied Natural gas is the future of the energy sector, as it is a source of clean energy. The liquefaction of natural gas is achieved at 111.67 K temperature, 1 atm; which is a cryogenic temperature. The cryogenic flow needs special attention because fluid, as well as material of the pipe, behave differently at cryogenic temperature. Two-phase flow is another critical point in the liquefaction of natural gas. The objective of this thesis work is to select the material of the pipe, calculate frictional losses in the pipe, and pressure drop in the pipe through which the cryogenic fluid flows. The frictional loss in the pipe mostly depends on Reynolds number, Roughness factor, and phase of flow. As the Reynolds number increases, the friction factor increases in a greater value. As the time lapses, corrosion and erosion factor plays a key role in frictional pressure drop. As there is an increment in pipe diameter, the pressure drop due to friction or frictional losses decrease but by virtue of that the weight of the piping system increases which is an unfavourable condition from an economic point of view. The flow in pipe encounters different forms of fluid in the liquefaction cycle of natural gas i.e. liquid phase flow, Gas phase flow and mix flow of liquid and gas. The Liquid flow and gas flow in a pipe are mainly deal with the Colebrook equation. Two-phase flow is a critical phenomenon in the liquefaction cycle. The pipe sizes mentioned in the result can be used for experimental setup. It is found that the corrosion factor is 0.3 and 3 mm respectively for a period of 30 years. Also, it is found that, there exists two phase flow after the joule Thomson expansion device. While selecting the pipe size, it has been observed that the thickness of the pipe greatly depend on internal pressure of the flowing fluid.
Process improvement in shipbuilding by implementation of predictive maintenance within the shipbuilding 4.0 environment
(Indian Maritime University, Kolkata Campus, 2019-06-19) Kumar, Rishi; Sinha, Sudhir Kumar
Shipyards use a variety of machinery and equipment in the process of ship building. The equipment is complex and requires expertise in handling and maintenance. The productivity of the shipyard is closely related to effective use of these machinery and equipment. The shipbuilding productivity in India is not among the best in the world. There are many reasons behind the lesser productivity, one such factor was identified by me is in the inability of the shipbuilding industry in adopting the technological advancements quickly. Industrial Internet of Things (Industrial Internet of Things) is a latest philosophy that has shown to be having many advantages. This technical leap if implemented may be called a Shipbuilding 4.0. IIOT can help in will change the structure, fabricating, task, shipping, administrations, creation frameworks, support and esteem chains in the all parts of the shipbuilding business and effect of the Shipbuilding 4.0 will be huge in shipbuilding machinery maintenance as well. In this project I have proposed a model to improve the shipbuilding process by proposing a usage prototype for implementation of IIOT in the shipyard based on findings and analysis of the causes of mechanical failure in major shipbuilding machinery in the shipyard, followed by an audit of the present day scholarly and mechanical advancements.
Sensorless field oriented control of AC induction motor using PI, PD & PID controllers
(Indian Maritime University, Kolkata Campus, 2022-09) Antony, Nikhil John; Mishra, Deepak
This dissertation focuses on the effective utilization and feasibility of fieldoriented control of AC induction motor using PI, PD and PID controller without any physical sensors. The speed, torque and position in this scheme are estimated, analyzed and simulated with the help of motor control block-set in MATLAB/Simulink for a (10HP, squirrel cage induction motor). Separately excited dc motors due to their simplicity has been used extensively in numerous applications for high performance application. Induction motors have been used to replace separately excited dc motor because they are rugged, cheaper, lighter, lesser maintenance and has lower moment of inertia. With the FOC vector approach, the control of the induction motor behaves similar to that of a separately excited dc motor. The torque and flux components in the d-q rotating reference frame can be independently controlled with the help of unit vectors. Based on how the field angle is used to determine the unit vector, the vector control scheme is classified into two, direct vector control using the measured field angle and indirect vector control using the evaluated field angle. The direct vector control is efficient but is also complex and reduces the reliability of the system especially for high-speed drives. The indirect vector-controlled induction motor drives primarily involve the decoupling of the stator current into the torque and flux producing component but it still faces the challenge that the motor parameters variate with temperature resulting in estimation error of speed in steady state and transient state. To overcome this drawback, flux observers are utilized to have better parameter variation effects and also speed accuracy. The dynamic performance of PI, PD and PID control techniques has been presented without speed sensors which improves the mechanical robustness, design space and reducing the overall cost.