Sharif Digital Repository

large ships should only make very small horizontal movements at the berth for efficient loading. This is especially a concern in ports facing the open ocean directly, where high swells at sea can cause harbor oscillations and low-frequency surge motions of the ship. A developed mooring unit, the MoorMaster, which replaces conventional mooring lines is addressed here. The hydraulics of the system have a strong reducing effect on the motions of the moored ship. Measurements have shown that the surge motion of container ships was reduced from an amplitude in the order of 1 metre to an amplitude in the order of 5 centimetres, by using MoorMaster units. In here MoorMaster action is divided to two... 

One of the most significant challenges and issues that port engineers and coastal specialists face in the field of improving port performance is the design and development of hardware systems to enhance the efficiency of loading and unloading operations of ships. These systems need to be designed in a way that reduces the duration of loading and unloading operations of ships and improves the efficiency of cranes. One efficient technology in this field is the Automatic Mooring Systems, which are connected to the hull of berthed ships and use hydraulic cylinders to generate control forces. On the other hand, as evident in today's world, artificial intelligence is recognized as a vital and key... 

The discovery of oil and gas resources in deep waters led to the invention of various platforms adapted to these waters. As the search for oil and gas resources is advanced to deep water, it is impossible to use fixed platforms in these depths. Hence, the idea of using floating platforms that can be used in deep waters has been increasingly considered. An option for the exploration and extraction of offshore oil resources is semi-submersible platforms. Under wave, wind, and current forces, a floating structure moves from its initial location. Types of mooring systems are used to maintain the position of the platform. During the life of a platform, mooring lines may be damaged under... 

We explain new interval methods, recently introduced in the literature, for solving unconstrained and constrained global optimization problems. The strategy is characterized by a subdivision of the argument intervals of the expression and a recomputation of the expression with these new intervals. By varying the selection and termination criteria, we explain new variants. These methods are used to solve problems with an objective function that has possibly a large number of local minima and constraints that may be nonlinear or nonconvex. We describe algorithms that return global minima and points at which the objective function is within a defined distance from the global minima. Numerical... 

Tension leg platforms (TLP) are vertically moored with reserved buoyancy used for drilling and production in deep waters. Pre-tensioned tendons controls the heave, pitch and roll motions due to marine currents and waves efficiently. Seastar platforms are new generation of tension leg platforms that are similar to spar platforms that has the advantages of TLP besides spar simultaneously. This platform is usually considered as an alternative for large and cost consuming platforms. Seastar has a cylindrical surface piercing hull that creates the required buoyancy along with three submerged additional bodies. Pre-tensioned cables are attached to platform through these three submerged bodies. The... 

A Tension Leg Platform (TLP) can be difined as a vertically moored, buoyant and compliant platform, where the excess buoyancy of the platform maintains tension in the mooring system (tethers). This platform type is usually used for drilling in deep water and includes the following sections, foundation, tendons, risers, hull and deck which is the most important section in terms of hydrodynamic forces and weight. Enough initial tension can be used to inhibit vertical movement of the structure. one of The main properties of this oil platform is extraction at large oil fields. Body of TLP is consist of vertical column, horizontal circular or rectangular cross section Pantoons and circular... 

Every day requirements for oil, gas and exploration in deep water have pushed offshore industries into deeper water. Oil production is expensive, so a designed platform should be cost saving. The clear and logical part is that, testing a model will be an important part of these kind of researches. In this thesis we are trying to obtain numerical results from ANSYS AQWA and experimental results for surge, heave and pitch motions, then compare experimental results with numerical one. Second order effects are ignored in designs and experiments because of laboratory conditions and limits that we are faced with in there. 1/250 scale ratio has been chosen because of limits. First we get into... 

Designing of giant oil platforms in deep seas is one of the most important challenges of the country’s oil industry. The valuable reservoirs of oil and gas in caspian sea, increases the need of designing platforms for drilling these regions. One of the platforms which is drilling in this region, is Amirkabir platform. In this research, at first this platform is modelled in AQWA software and analyzed. This analysis includes finding loads acting on the platform and consequently RAOs of different degrees of freedom in different directions and also the time history of motions of the platform and tensions in its mooring cables. Motions of moored floating platform consists of two types of motions.... 

Offshore wind energy is widely recognized as a renewable energy source that has the potential as a global energy source. Although the use of coastal wind turbines has been successful, it has been challenged in terms of visual, acoustic and environmental impacts. In addition, in terms of technology, it is difficult to achieve high levels of energy from coastal wind resources due to low annual average speed; Therefore, the wind energy industry is trying to make more use of the deep-water wind resources. However, before developing these types of deep-water turbines, economic challenges and technical problems must be resolved. Mooring failure is one of the major issues in the design of offshore... 

In recent decades, SPM system has become a great method for transferring petroleum products to tankers and vice versa. SPM technology has shown his confidence and operation abilities. Sea waves are the most important phenomenon to be considered in the design of coastal and offshore structures. In this study dynamic motion of SPM floating structure is modeled under sea waves loading. Mooring lines connected to structure is modeled by using static stability equations and equivalent stiffness matrix is computed. First the SPM floating structure motion is modeled in 2 dimension (3 degree of freedom) using the boundary element method in frequency domain under regular sea waves loading and the... 

For the stability of floating solar PV power plants against environmental forces and the safety of operators during maintenance and repair, the mooring system ought to be designed based on the position of the plant, the size of the plant, and weather conditions. Floating solar PV power plants are mostly located in reservoirs with significant water level variations, or in some cases in inland seas where changes in water level are the most important challenge in their mooring system. In this project, different methods to overcome the water level variations have been studied and finally, a creative idea which covers the weaknesses of previous ones has been represented. By using programming...