Sharif Digital Repository

The turbulent waves of the sea and their impact have always been one of the challenges of marine activities. Recently, with the world economic development and the boom of maritime tourism, providing comfort for the occupants of ships and boats has become one of the issues of engineering concern. Therefore, different methods are used to address this challenge. In this article, we first review these methods and then try to choose the optimal method and design a system for a relatively small boat that can compete with other methods. The method of choice is "damping mass", which has never been used to reduce the movement of boats. In this paper, by obtaining the equations governing the physics... 

Jetsurf is a recreation vessel at sea. It is a surfboard that is equipped with a motor propulsion system and provides surfing, which is an exciting and popular sport, in calm seas, lakes, dams, rivers and natural and artificial canals. This project is divided into four steps. In the first step, the appropriate dimensions for the design of this device are specified. In the second step, to calculate the resistance of jetsurf, at first a model with similar dimensions including experimental results in Star CCM+ software was validated by computational fluid dynamics method and Overset dynamic mesh technique and then jetsurf resistance with dimensions of 1.8x0.6x0.225 meters was calculated. In the... 

The fuel consumption of displacement ships is one of the vital and sensitive issues in the marine transportation industry, which affects all economic and environmental aspects. There are few important parameters for displacement ships that can be changed and optimized to reduce fuel consumption and the resulting pollutants. In this study, extreme trim has been selected as one of these important parameters and it has been studied numerically using Star CCM+ software. It should be noted that the extreme trim approach is used when returning from a trip (when there is no load). The results obtained in the extreme trim mode showed a decrease of 26.76% in the resistance of the KVLCC2 tanker-ship... 

Having a large source and volume of data from various machinery and electronic devices, as well as the aggregation and diverse uses of this data for higher productivity, greater safety, increased reliability, and ultimately higher profits, is a necessity and demand in every industry. This is especially important in the maritime and shipping transportation sector. The solution to predicting and preventing wear, failure, and ultimately the breakdown of vessels is to have data that is continuously and automatically collected from the ship, with the capability for transmission and analysis. The goal of this project is to develop a cost-effective system for monitoring lightweight vessels, which,... 

Occurrence of scouring around the seabed pipelines can lead to pipe failure and pose a serious threat to the marine environment, economic losses and waste of oil and gas. Therefore, to prevent the occurrence of scouring, by simulating this phenomenon and identifying the parameters affecting it, we can help to design a more efficient placement of pipes in the seabed. Various methods such as potential flow theory and turbulent single-phase and two-phase models have been proposed to simulate this phenomenon. The purpose of this article is to simulate and investigate the effective parameters of this phenomenon by combining computational fluid dynamics and separate elements. The innovation of... 

The minimum cost of energy is the goal of the wind farm layout optimization. This can be achieved by either maximizing the total energy or minimizing the total costs of the farm. This thesis considered the effect of wind speed on the performance and thrust coefficients. We also used two sizes of commercial turbines. First, we started by a single variable objective function (turbine cost to generated power), then, considering cable, foundation and O&M modules, objective function changed to a LCOE function which is non-dimensionalized by dividing all the costs to the cost of one turbine. We modified the simple cost model proposed by Mosetti et al., using cost scaling law, and also included... 

The repair, maintenance and cleaning of marine equipment and ships, as well as the optimization of these operations to reduce their costs have always been of interest to researchers. After a few hours of floating in seawater, an inanimate organic layer forms on the surface of marine structures. After a few months, the thickness of this layer increases. This will increase the drag by 30 to 40 percent. Hull cleaning operation increases efficiency, saves time and money, prolongs equipment life and reduces maintenance and repair costs.In this project, the types of marine fouling according to environmental conditions were identified, next a type of fouling (Barnacle) was selected, which has more... 

Today, the cleaning and moss removal of the hulls of ships is very important due to the strict and international laws of reducing pollutants and the exorbitant cost of fuel of the country's navy. The advantages of cleaning the hull of vessels are reduced fuel consumption, increased ship speed and longer hull life. Traditionally, the hulls are cleaned by divers, and in recent years the use of crawling robots has been welcomed by the industry because of its benefits. This important thing in Iran is still done by divers and therefore the need for indigenous development of such robots in the country is felt.In the present study, the aim is to design and build a reliance system for the ship's... 

The employment of strategies with low operational and capital investment to reduce ship's voyage costs is gaining considerable attention. With rising fuel prices, shipping companies are concerned with the increase of fuel costs of the ships. In this research, the smart steaming strategy, including the simultaneous optimization of ship's sailing route and speed, is proposed as an efficient alternative for the slow steaming to minimize ships' fuel consumption and voyage costs. By implementing the smart steaming strategy, ships owners can ensure that the ship sails at the optimal and safe sailing route and reaches the destination port on time. In addition, the proposed shipping strategy can... 

One of the main methods to reduce fuel consumption and emissions is using renewable energy resources. This research proposes a hybrid renewable energy system on a container ship which includes one photovoltaic solar system, and one kite system. The photovoltaic system produces a part of the ship's electric power consumption and the kite system produces propulsion force using wind energy and transmitting this force to the ship through towing rope. Different components of these renewable energy systems are connected with the internet of things technology. In the internet of things structure design section, in addition to the conceptual design of different layers with emphasis on the processing... 

The aim of this research is to investigate the effect of speed and direction of current on ship fuel consumption. A KCS benchmark model has been numerically studied in calm water and fourteen current and wind conditions with the same speed and different directions to determine how the ship performance is dependent on flow conditions. The model has been simulated in an artificial basin propelled by a single right-handed propeller via a CFD commercial code. Numerical results revealed a linear relationship between the deviation of current and wind from head-sea or following-sea conditions and the rudder angle. The head-sea and following-sea currents and winds increased and decreased the lateral... 

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... 

every year large amounts of sedimentation are getting dredged all over the world. Dredging operation includes several processes such as excavating from the sea bottom, transferring them to the surface, and most important, releasing them in another area which can cause a sediment particle cloud that can be really harmful to the surrounding environment. Therefore, accurate analysis of this phenomenon is necessary to prevent catastrophic damages. The Eulerian-Lagrangian numerical method considers both sediment particles and fluid physics for a better simulation of near-field area. In this project, after investigating open-source available software for the Eulerian-Lagrangian simulation, a new... 

The hulls of various ships are exposed to the problem of biofoulings on the hull after a period of time due to use in the salt water environment of the sea and the existence of suitable conditions for the growth of marine plants, so that the ship after about one month of stopping in the port, in order to start the activity again, it is necessary to clean the hull from these biofoulings. The ship will be transported to the dry dock for cleaning only when it is heavily involved in biofoulings on the hull, and in the meantime, it must be periodically cleaned in water by other systems, including the diver and robotic systems.Using a robotic system to perform this operation has various... 

In the initial part of this research, 10 selected dams out of 647 existing dams in Iran were selected using ArcGIS software, based on 3 indicators of height above sea level, temperature, horizontal solar radiation and wind speed, and the shadow model was calculated by calculating the radiation angle. The solar radiation on the reservoir water level of one of the selected dams, which is Durood Zan Dam, was checked on 4 days of the year. In the next stage, the design of the floating part of the power plant and its related components, in 3 parts including the main door, the door The pontoon and the main pontoon were done. Platform dimensions were optimized during the design process and to... 

In this project, experimental investigation and optimal design of the aquaculture netwasher process for biofouling removal have been studied. In the first phase, various types of marine biological deposits and their characteristics were examined, and the most prevalent type with the highest adhesion was selected for the net. In the second phase, different cleaning methods were evaluated, and the most efficient method considering cost, equipment, and speed was chosen. Following an assessment of the challenges, advantages, and disadvantages of the mentioned methods, a rotational disk system was selected as the preferred system due to its cost-effectiveness, cleaning speed, reduced damage to...