Analysis of Turbulent Flow on Tidal Stream Turbine by RANS and BEM

摘要

Nowadays,concerns arise because of the depletion of fossil fuel resources that forced scientists to develop new energy extraction methods.One of these renewable resources is tidal energy,where Iran has this potential significantly.There are many ways to obtain the kinetic energy of the fluid flow caused by the moon’s gravitational effect on seas.Using horizontal axis tidal turbines is one of the ways to achieve the kinetic energy of the fluid.Since this type of turbine has similar technology to horizontal axis wind turbines,they may be an appropriate choice for constructing a tidal power plant in Iran.This paper presents the numerical simulation and momentum method of a three-bladed horizontal axis tidal turbine.To validate the thrust and power coefficients for a fixed pitch angle at the blade tip speed ratio of 4 to 10 are compared with experimental results.In this modelling,the rotating geometry simulation has been used.Results show that using a numerical method and blade element momentum,we can predict the horizontal axis tidal turbine’s thrust with an error of less than 10%.The numerical method has better accuracy in higher speed ratios,and it is appropriate to predict the behaviour of fluid in collision with turbines and its wake effects.