Sharif Digital Repository

As it is obvious from the name of this study, the goal of doing this study is the feasibility study of southern shores of Iran for building an artificial energy island for and designing it. In this project by studying seven points coastwise of southern Iran and defining the criterions and scoring the points, the Chabahar was determined as the best place for erecting the artificial energy island. With respect to the environmental condition of the chosen point and modeling in software ANSYS, the structure of the artificial energy island has been studied and the type, geometric shape, area, trough, and the setting of the anchoring system has determined. As a result of these efforts, a hexagon... 

Dynamic increasing amplitude and period (DIAP) [1] is a time-domain analysis methodology developed based on endurance time (ET) analysis method [2], which can be used to evaluate the response of marine structures when encounters a continuous loading, such as storm conditions. In this method, instead of using separate records with different intensities, a single loading record with an increasing intensity over time is used for structural analysis. The ability to enter spectral concepts, considering the effects of waves with different frequencies and amplitudes, taking into account the effects of randomness of waves and the possibility of short duration analysis are some of the specific... 

The purpose of this study was to design a Free Fall Lifeboats body for offshore platforms, then hydrostatic and hydrodynamic analyzes, focusing on the aircavity formation on the back of the boat. In the first section, previous studies and a history of this has been discussed. Then the free fall bases are described along with the various stages of launching the Free Fall Lifeboat. In the next section, the Free Fall Lifeboat's body was designed and then analyzed and lunching procces has been simulated using the star-ccm+ software. the boat with seven different parameters is solved under the assumption that the air is incompressible, in which the primary conditions are the water entry angle... 

One of the utmost important factors during salvage operation of drowned ships is raising velocity. Uncontrolled raise is a dynamic phenomenon which can lead to the sudden tensions, collapse in airbags or ships. Studing this issue helps the engineers which kinds of problems are more important during salvage operations. This study focus on modeling and analysis of raising movment of the ship with FLOW-3D and ABAQUS software.
In FLOW-3D environment, hydrodynamic analysis of rising movment of drowned ship has been done. We should mention that applied forces and velocities and other parameters from the FLOW-3D output should be passed IMCA Criteria to avoid uncontrollable raise. In ABAQUS... 

Two experimental models were designed and tested to extract energy from vortex induced vibrations of a elastically mounted one degree of freedom rigid cylinder in the Reynolds range of 120000 < Re <220000. In the first model the amplitude and frequency of the movement was measured then a second model was designed to be tested in the Emam Hossein marine laboratory. The model was designed in a way that many of its properties like mass ratio, spring constant and damping coefficient were able to be altered. In this study the vortex induced vibration of an elastically mounted cylinder was scrutinized in high Reynolds and very low mass ratios for the first time and an amplitude ratio of 2.49 were... 

Marine current power has been utilized in recent years as one of the most foreseeable renewable energy sources. In this study a multi-objective hydrofoil optimal design is carried out for use in marine current turbine in order to improve hydrodynamic performance due to low speed current in Qeshm channel. A particle swarm optimization code using FORTRAN is developed and coupled with XFoil software as flow solver that is based on panel method. B-spline curve is used to parameterize the hydrofoil shape and the coordinates values of the control points are designated to act as optimization parameters. Validity of flow solver examined by comparison made between computed data against experimental... 

The growing requirements for renewable energy production lead to the development of a new series of systems, including wave and tidal energy conversion systems. Due to their sensitivity and the impact of the aggressive marine environment, the selection of the most adequate location for these systems is a major and very important task. Several factors, such as technological limitations, environmental conditions, administrative and logistic conditions, have to be taken into account in order to support the decision for best location. The aim of the present study is to provide an Atlas of IRAN Offshore Renewable Energy Resources (hereafter called ‘the Atlas’) to map out wave and tidal resources... 

Darrieus turbines are one of the most widely used turbines in extracting energy from tidal currents. This study aimed to investigate the effect of utilizing helical blades and variable solidity ratio on the efficiency of Darrieus tidal turbines. For this purpose, three types of helical turbines with different solidity ratios have been designed, and computer simulation has been used to investigate the effect of the mentioned parameters on the efficiency of the Darrieus turbines. According to the simulation results, the helical turbine has less efficiency than the straight blade Darrieus turbine. The maximum hydrodynamic efficiency of the Darrieus turbine with straighted blades is 38.5,... 

This study presents a hydrodynamic and performance analysis of a small research submarine, aiming to optimize its design, enhance efficiency, and ensure safety under operational and emergency conditions. Given the increasing importance of underwater exploration and research, various submarine models were initially evaluated in terms of design and performance. The Myring subsurface model was selected as the optimal design due to its favorable fullness ratio and the ability to approximate the hull shape to a spherical geometry. The submarine's dimensions were specified as 3 meters in length and 2 meters in diameter, suitable for small-scale research missions at moderate depths. To investigate... 

Nowadays, because high global demand for energy has led to the extensive use of fossil fuels with numerous unintended consequences such as air pollution and greenhouse effect, research and development around optimization of energy infrastructure has become much more important. Consequently, many scientific approaches have been applied to replace fossil fuels with renewable natural energy resources. One of the renewable energy types that fewer papers have been published about it, is the enormous energy of Marine currents. The origin of this energy is mostly tidal effect, or ocean currents that are available in most of oceans and seas around the planet earth. The most important criteria for... 

The idea of using under water vehicles inspired by nature has gained considerable attention during the past few decades. This interest is due to the advantages of swimming and moving by this technique, in comparison with the conventional methods. Benefits are such as increasing speed, improved power, better manoeuvre ability,greater stability, optimal hydrodynamic performance ... etc. The purpose of this study was developing a model to simulate a stingray Manta Ray moving behaviour. Ansys- Fluent software was applied to solve the related equations of viscous laminar flow in 3-D form.Simulation of Manta Ray was performed with the flapping pectoral fin with dynamic mesh. Using this... 

In this work, we use computational fluid dynamic simulation tools for investigation two dimensional of eel movement. Firstly, the numerical study of smooth particle hydrodynamics was applied for determination drag coefficient and lift coefficient of undulation movement eel body. The initial mesh was manual. So, the effective parameters of eel movement were investigated. The smooth particle hydrodynamic method was not use, because of saving on time. Therefore, fluent software was used. UDF were added to the fluent software, which it can be move the boundary layer of mesh with eel movement. The dynamic mesh tools of fluent software were used. Initial shape had a curvature and utilized for... 

In the recent decades, because of the reduction of the fossil sources and increasing the environmental pollution, also worldwide population growth and the necessity of energy have made humanbeing to use the Renewable Energy. Wave energy is an opulent source of energy in many parts of the world, especially in Iran.
In this thesis, in the first chapter, different kinds of renewable energy are introduced, and the importance of them is discussed. In the second chapter, the mechanisms of extracting energy by the wave energy converters are investigated, and their types are discussed. Then, in the next chapter, wave equations, wave spctrums and simulation of a flap wave energy converter in... 

Tsunami, like many other natural disasters leaves people a short time for escape. When talking about Tsunami, the escape time is the period it takes for the wave to start moving from the epicenter, change into a giant wave gradually and reach to a cost. In order to minimize damages of this phenomenon, the escaped time has to be estimated without delay. For this purpose the first needed action is modeling the Tsunami waves. Analytical and numerical models and software that are designed based on them do exist. To have an efficient and rapid Tsunami alarming system all of these options are examined in this project. Then having a reliable model quite a few probable scenarios are propounded. The... 

The thesis title is “Modeling of a vague problem (Floating Breakwater by BEM Analysed) using ANFIS (Adaptive Neuro-Fuzzy Inference System) and validation by Fuzzy Boundary Element Method”. In this set of material, more important definitions are described below. When some input data is linguistics, or we have lack of Information or Vagueness, Fuzzy toolbox can alleviate the problem. Fuzzy concept includes several fields and applications like; fuzzy logic, fuzzy sets, fuzzy control, fuzzy arithmetic and fuzzy inference, and the last two applications are used in this thesis. The Neural network is a black box, Neurons that can justify their actions and these artificial brains can grow. The... 

Human have been thinking to discover all secrets of world, from long time ago. And also the sea exploring and using its resources, including oil and utilization of fish as feed have been the main causes of human interest to ocean. So to access these resources, constructed some equipment to be able to go under water, such as ROV and AUV.
Since the human is concluded that further facts need to synchronize to the world with the natural laws of nature in this area is the best model and teacher; new branch of science called bionic is exploded. For example, look and study of birds in the air movement have produced the fastest aircraft. Same knowledge in the field of marine sciences has... 

For more than a million years, aquatic animals and specially fishes make undulatory motions in their flexible body to propel themselves. In the recent decays, scientists prove that these mechanisms are more efficient than man-made propulsion systems. A wide variety of artificial vehicles including robotfishes, ROV and etc has been manufactured with inspiring by natural creatures. The Biomimetic science which deals with the study of mechanics and hydrodynamics of living creatures is very important in developing these vehicles. In the present study, numerical software (PANEL3D®), bases on boundary integral equations of potential flow have been developed to simulate hydrodynamic performance of... 

Given that achieving the form of hydrodynamic hulls has made it possible to reach higher speeds, much research has been conducted today to reduce the drag force exerted on vessels and to keep them stable in calm and rough water in deep and shallow areas.In this project, a catamaran garbage collector vessel has been designed and developed specifically for the cleaning and collection of surface waste in ports. The design of this vessel aims to reduce the environmental impact of floating waste and improve the efficiency of cleaning operations. The double-hull structure (catamaran) of this vessel allows for high stability and hydrodynamic efficiency.To evaluate the performance of this vessel,... 

The leads with heavy current passing through the covering plates, and the winding in a transformer, are sources of eddy current losses. Due to this loss some regions of tank wall are subject to serious local overheating. It affects the safety and reliability of this expensive bject and power delivery.Heavy current in large power transformers and special type transformers give rise to a concentrated passage of eddy currents which in turn cause high local losses and overheating in the metallic parts especially in the steel tank walls of transformer.This local overheating is dangerous for transformer oil and the solid insulations. Therefore the calculation of losses and proper design of...