Performance and Wake Recovery Analysis of A Lift-driven Helical Hydrokinetic Turbine: A Numerical Approach

The lift-driven helical hydrokinetic turbine (LHHT) technology is one of the promising options to facilitate a green source of renewable power that can noticeably diminish the carbon footprint of nearby river communities by harnessing kinetic energy. However, to generate ample electrical energy for end-use applications, multiple turbines must be deployed in sites hence wake recovery analysis under different operating conditions is receiving a lot of research interest. The present study numerically simulates a LHHT rotor model having an aspect ratio of 0.75 and solidity of 0.30 to investigate the performance and wake recovery distance under different tip speed ratios and flow velocities considered in the range of 0.6-1.4 and 1.0–2.0 m/sec, respectively. Moreover, an experimental study was also conducted to validate the numerical approach and found good agreement in performance results. Simulation outcomes show that a peak power coefficient of 0.17 is perceived, corresponding to a V of 1.0 m/sec; however, it drops significantly with an increase in velocity. The wake velocity deficit is found to be dissipated at a distance of 17, 15 and 15 times the rotor diameter from the centre of rotor with minima of <0.05 for V of 1.0, 1.5 and 2.0 m/sec, respectively.