Sharif Digital Repository

Nowadays, science and technology, once again, lead approach to renewable natural resources to access energy due to fossil resources restrictions. Growing need for energy, being concerned about exhaustion of fossil resources, environmental pollution caused by burning fossil materials, climate warming and the greenhouse effect and etc. are obvious evidences of aforesaid fact. On the other hand, oceans and seas are large reservoirs of energy which comes from sunlight, geothermal resources, Earth's rotation and gravity by means of mechanical and hydrothermal processes. During the years, many ideas were conducted to achieve and mine the mentioned enormous energy potential of the oceans and seas.... 

Rapid growth in energy consumption and environmental concerns over conventional power generation technologies has increased the need for alternative energy sources. Kinetic hydropower has been available for decades, however, despite its minimal environmental impact, commercialization has been limited. The main purpose of the first part of this thesis is investigation of flow properties near the convergent-divergent nozzles with various geometries. Two parameters that studied include variation of drag force on body and mean velocity of water flow in middle cross section. In the second part, we studied a horizontal marine current turbine (which its geometry is taken from a NREL wind... 

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... 

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...