A novel design of nozzle-diffuser to enhance performance of INVELOX wind turbine

In this study, the performance of Invelox Wind Turbine, under the effect of geometric changes in the nozzle-diffuser section, is investigated by Finite Volume Method. To follow a more realistic approach, the wind speed equation is applied to the inlet. The effects of ratio of the length to nozzle cross-sectional area, diffuser length, diffusion angle, various nozzle design standards, also the angle and height of the added flange were described by the pressure and velocity distribution contours. The results showed that when the ratio of the nozzle length to throat diameter rises up to an optimum value, the channel flow rate increases and after that it begins to decrease. Then, the RSM optimization method was employed to optimize the diffuser, and optimal values of diffuser length to throat diameter and diffuser opening angle to nozzle opening angle ratios were obtained. Also, to apply the ideal nozzle the system was geometrically optimized to meet the Invelox system requirements. After that, the power rise due to adding the outlet flange was studied, and an appropriate geometric ratio was achieved. Finally, the system performance, when the turbine was modeled as a uniformly loaded actuator disc was investigated to find the most efficient turbine.