Hamid Rahmani - Department of Mechanical Engineering, Semnan University, Semnan, Iran.
Mojtaba Biglari - Department of Mechanical Engineering, Semnan University, Semnan, Iran.
Mohammad Sadegh Valipour - Department of Mechanical Engineering, Semnan University, Semnan, Iran.
Kamran Lari - Department of physical oceanography, Islamic Azad University, Tehran-North branch, Tehran, Iran.

With regard to energy crisis in the world and also world population growth, the use of new energy sources for electricity generation is essential. New energy sources are renewable and do not lead to environmental pollution. In a world where oceans form more than 70% of it, the use of hydrodynamic energy is on the rise. But the growth of this issue is far from sustainable development. This study aims to develop an innovative project regarding energy extraction from tides (wave) on the southern coast of Iran with respect to the investigations, experiments andresults of this type of energy extraction in the world. In this research, a laboratory model of a helical turbine has been initially built by researchers and system modeling was then performed to improve the function of the above machine using software such as ANSYS. Numerical results obtained were consistent with the empirical data. This indicates the validity of numerical modeling. Afterwards, innovative designs have been provided and analyzed to increase turbine efficiency. To this end, various geometric shapes have been considered for the blade. It has been shown that helical blade with BW3 airfoil acts better than spoon blade which is of Darrieus blades type.

Numerical, Variable velocity, Tidal current, Blade, Power