الفهرس 
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Abstract
Oceans are endowed with vast renewable energy resources such as; tidal, wave and, current, the focus in this work will be on current energy. Ocean Stream Power Generation (OSPG) concept is considered to be one of the most important potentials for future electricity generation and cover a significant portion of the global energy consumption and provide yet another sustainable alternative to fossil fuels as a source of energy. However, ocean renewable current energy can still be considered in development phase and is not commercially available in large scales. Existing marine turbine systems, for instance, are mostly in prototype testing stage. Although initial results are quite promising, some further verification for long-term performance and durability under severe environmental conditions is still required. Consequently, marine current turbines must be designed with survivability as well as cost effectiveness in mind. The idea of this thesis is to optimize the design and the hydrodynamic performance of the Fin Ring horizontal axis hydrokinetic marine current turbine (HAHK). The unique fin-ring turbine is a patented unconventional horizontal axis marine current turbine. The turbine comprises 7 concentric rings with 88 connecting cambered fins and a solid centre hub. The 4 outermost rings have 16 connecting fins per ring while the 3 innermost rings have 8 connecting fins per ring. The novel concept of the turbine design is to develop a configuration that is efficient and low cost design to ensure safe continuous energy production and facilitate the deployment of the device at various locations with different current speeds. The main objectives of this work are to determine the effects of various design parameters, such as the fins’ pitch angle θ, camber length and aspect ratio on the extracted output power and conduct an optimisation study to maximise the output power leading to an optimised feasible proposed design. To do so, numerical modeling using ANSYS FUENT has been performed by applying computational fluid dynamics (CFD). The continuity, Reynolds Averaged Navier-Stokes – RANS equations and the fully turbulent K-ε turbulence model are numerically solved. The entire numerical global optimization process has been carried out using ANSYS DesignXplorer module. The generated design points were simulated and all together with the results were put in a matrix format, the design points and their results were modeled by ANSYS Design Of Experiments (DOE) using the custom method, then the Response Surface was generated using ANSYS Response Surface Method (RSM) based on the results of the (DOE) to find the optimum design. To put the optimised turbine’s performance into context, a previously published article of the CFD hydrodynamic performance analysis of the original turbine’s design validated with the patent model is used as a benchmark design for comparison. The results of all the previous studies adopted to maximize the turbine’s hydrodynamic efficiency show that, the turbine’s efficiency has been increased by 105.78 % from the benchmark design. To prove and show the superiority of the turbine’s novel design, the turbine’s performance is compared to one of the conventional hydrokinetic turbines in the literature review.