Numerical investigation of wind efficiency improvement by using nozzle and diffuser in wind turbines

In this study; Increasing the performance of wind turbines, which are used to convert wind energy into useful energy which is one of the renewable energy sources which has become a necessity due to environmental reasons today with passive equipment such as nozzles and diffusers has been numerically examined. ANSYS Workbench 2020 R2 program which is a Computational Fluid Dynamics (CFD) program was used within the scope of the study. A total of 10 different numerical analyzes were performed by using nozzles and diffusers created in different types and combinations in a horizontal axis wind turbine (HAWT) with a rotor of approximately one meter in diameter. Analysis results were visualized with the ANSYS CFD Post module, and average velocity and pressure values were obtained. The findings obtained by using the results in the wind power and wind performance coefficient equations were evaluated. According to the findings obtained from the study, The nozzle, diffuser and flange (brim) combinations in certain designs increased the speed in the rotor section by 37%, increasing the total wind power by 1.5 times and the wind performance coefficient more than 2 times. It has been concluded that this increase is due to the effect of nozzle and diffuser geometries reducing the pressure difference in the direction of the flow axis.