Deepwater Engineering Research Center, Harbin Engineering University
Tidal energy is the most foreseeable form of renewable energy. Tidal energy can be harnessed by tidal barrage, tidal fence and tidal current technologies. Present efforts are focused on diffuser augmented tidal turbines that exploit the kinetic energy of the tidal currents. The power output by a tidal turbine is directly proportional to the cube of velocity of incoming fluid flow. Thus, even a minor increase in velocity considerably increases the power output. The diffuser helps accelerate the incoming fluid flow. Hence, the efficiency of the turbine is substantially increased by using a diffuser. Many research groups are investing considerable time and financial resources in this emerging domain. Limited results are available for diffuser augmented tidal turbines due to their emerging nature, large and costly research and development setup, startup cost and proprietary issues. The purpose of this paper is to study NACA 0015 airfoil for diffuser design for tidal current turbines. Numerical simulation of the diffuser is carried out to check the velocity and mass flow rate at throat. The drag, for various NACA 0015 diffuser models, is also calculated on the diffuser.