The transition to sustainable energy systems requires the development of efficient hydrokinetic technologies to increase the reliability and competitiveness of renewable energy generation. Vertical-axis H-Darrieus turbines can improve their performance through impeller channels or external flow guidance devices that modify the local mass flow distribution around the rotor. This work introduces a systematic geometric optimization framework that quantitatively evaluates the combined effect of key channel design parameters on turbine performance by employing response surface methodology (RSM) to quantify the influence of two geometric parameters of an impeller channel—specifically, the deflection angle (β) and the channel length (H)—on the turbine power coefficient (Cp). This approach allows for the identification of nonlinear interactions between geometric variables, which have not been explicitly addressed in previous research on impeller channels in H-Darrieus turbines. An experimental design with thirteen treatments was implemented, and numerical simulations were performed using Computational Fluid Dynamics (CFD) in ANSYS FLUENT®. Statistical analysis of the RSM model showed that both β and H have significant effects (p<0.05) on turbine performance. The model predicted an optimal configuration with β equal to 100° and H equal to 0.2 m, corresponding to the maximum Cp achieved. These findings confirm the potential of impulse channels to improve the aerodynamic efficiency of H-Darrieus turbines and establish a quantitative basis for design optimization in hydrokinetic applications.
Múñoz et al. (Fri,) studied this question.