Experimental study on the optimum design of diffuser-augmented horizontal-axis tidal turbine

Ocean current energy is a promising and reliable resource that offers sustainability and predictability in realizing green future needs. A diffuser-augmented horizontal-axis turbine is utilized to generate ocean current energy. A numerical study on the impact of diffuser angle variations on the power coefficient has been carried out in the previous research. To elucidate the fluid dynamics aspects and further validation of previous computational results, the experimental investigation on the optimal design of tidal turbine with 20.04 degrees diffuser augmentation is presented in this study. The study was conducted in a flowing tank with a current velocity of 0.7 m/s. The maximum power coefficient of 20.04 degrees is 0.436 experimentally, which is a little smaller than the numerical value. Moreover, to reinforce the 20.04 degrees result, a diffuser with an angle of 10.43 degrees was also manufactured and tested experimentally. The maximum power coefficient of 10.43 degrees is 0.303 experimentally, which is 3% smaller than the numerical value. It was concluded that the numerical approach might be considered satisfactory and represent similar phenomena to the experimental investigation in an application for modelling of multi-objective optimization. A diffuser-augmented horizontal-axis turbine to generate ocean current energy is studied experimentally. The results compare well with a previous computational study of the turbine design. It was concluded that the numerical approach is a satisfactory representation of the experiments for use in future multi-objective optimization.