• CHAPPA SURESH
• C. NEELIMA DEVI

The wind flowing through a diffuser-augmented wind turbine travels along the walls of the diffuser causes in the exiting wind to form vortices of wind when exiting and these vortices cause most of the air to be diffused away from the centre of the exit, which creates a low pressure segment of air behind the turbine which accelerates the high pressure air in the front towards the low pressure air in the back, causing a significant increase in rotor speed. A three bladed horizontal axis wind turbine with a diffuser surrounding the blades is considered in the present study to investigate the power enhancement achieved. The wind turbine power output, efficiency with and without augmenting ring is estimated at rotor speeds varying from 0.5 to 2 Rad/sec at wind speeds ranging from 8 to 24 m/s using Ansys 18.1 CFX software. It is observed that at all rotational speeds, the effect of diffuser is less at higher wind velocities (beyond 16 to 18 m/sec) and maximum power augmentation at all rotor speeds is realized only at 16 to 18m/sec. For turbines installed on land, the average wind velocity in India ranges from 20 to 40 km/hour (6 to 12 m/sec) and hence using diffuser would be definitely an added advantage without additional investment cost. The power coefficient showed rapidly decreasing trend with increasing wind speed and attains very low values at speeds greater than 20 m/sec. At 8 meters/sec the coefficient exceeded Betz limit of 0.59 at 1. rad/sec and hence running turbine at speed beyond 1 rad/sec is not feasible. With regard to thrust coefficient It is seen that the trend of decreasing value with increasing wind speed is similar to power coefficient and also lower values of both coefficients are realized for lower rotor speeds. It is also noticed from literature that this trend is similar to the other similar wind turbines. Further all the thrust coefficient values for turbine with diffuser indicated more or less same increase for all rotor speeds (20% for 12 m/sec at 2 rad/sec and 18% 12 m/sec at 0.5 rad/sec).

wind velocity, power coefficient, thrust coefficient, torque coefficient, tip speed ratio, output power, betz limit, winglet.

"PERFORMANCE OF HORIZONTAL AXIS WIND TURBINE WITH CONICAL WINGLET", International Journal of Emerging Technologies and Innovative Research (www.jetir.org), ISSN:2349-5162, Vol.7, Issue 10, page no.828-831, October-2020, Available :http://www.jetir.org/papers/JETIR2010104.pdf

"PERFORMANCE OF HORIZONTAL AXIS WIND TURBINE WITH CONICAL WINGLET", International Journal of Emerging Technologies and Innovative Research (www.jetir.org | UGC and issn Approved), ISSN:2349-5162, Vol.7, Issue 10, page no. pp828-831, October-2020, Available at : http://www.jetir.org/papers/JETIR2010104.pdf