International Journal of Mechanical and Industrial Technology ISSN 2348-7593 (Online) Vol. 2, Issue 2, pp: (51-78), Month: October 2014 - March 2015, Available at: www.researchpublish.com Page | 51 Research Publish Journals CFD Analysis of Wind Concentrator 1 Md Ahsan, 2 Ramniwas Bishnoi, 3 Sanjeev Kr. Singh Department of Mechanical Engineering, Niet- Nims Institute of Engineering & Technology NIMS University, Jaipur, India Abstract: Wind energy provides an attractive power source as an alternative to fossil fuels because it is abundant, clean, and produces no harmful emissions. To extract more energy from the wind we need to increase the wind turbine size. However, the increase in size has begun to reach a limit in terms of material composition and structural stability. To quell the trend of increasing size in wind power systems alternative wind turbine blade designs are investigated and evaluated to increase power production and efficiency of present size machines. Wind concentrators have been proposed for the turbulence flow and low velocity region because they provide structural and aerodynamic advantages. In this study, several selected concentrator designs were analyzed. A computational fluid dynamics (CFD) program was used to model air flow patterns through a prototype wind concentrator and optimize its performance. Through this method, it was determined that a concentrator with a disk shaped entrance and exit is effective at concentrating wind energy. Maximum velocities were obtained with the addition of pressure-relief slits in the inlet v portion. With an ambient inlet air stream of 8 m/s, CFD results predicted the concentrator would accelerate the air velocity to 18.56 m/s. The concentrator also predicted similar accelerations at higher inlet velocity. Our numerical simulations show that the circular disk shaped wind concentrator can increase velocity approx twice the inlet. I. INTRODUCTION 1.1 Wind Energy Wind energy is the kinetic energy of air in motion, also called wind. Total wind energy flowing through an imaginary area A during the time t is: where ρ is the density of air; v is the wind speed; Avt is the volume of air passing through A (which is considered perpendicular to the direction of the wind); Avtρ is therefore the mass m passing per unit time. Note that ½ ρv 2 is the kinetic energy of the moving air per unit volume. Power is energy per unit time, so the wind power incident on A (e.g. equal to the rotor area of a wind turbine) is: Wind power in an open air stream is thus proportional to the third power of the wind speed; the available power increases eightfold when the wind speed doubles. Wind turbines for grid electricity therefore need to be especially efficient at greater wind speeds. Wind is the movement of air across the surface of the Earth, affected by areas of high pressure and of low pressure. The surface of the Earth is heated unevenly by the Sun, depending on factors such as the angle of incidence of the sun's rays at the surface (which differs with latitude and time of day) and whether the land is open or covered with vegetation. Also, large bodies of water, such as the oceans, heat up and cool down slower than the land. The heat energy absorbed at the