Abstract
Horizontal axis hydrokinetic turbines capture energy from tidal, ocean, and riverine currents. Computational fluid dynamics can serve as a reliable tool for predicting fluid-turbine interactions. While uniform inflow conditions are common in the design process, the actual operating environments present turbines with flows that vary in both space and time. This study investigates the effects of sheared inflow as a spatially varying condition. Three linearly varying inflow velocity are considered and the performance and unsteady blade loading are evaluated. The findings reveal that sheared profiles result in a slight increase in the turbine’s overall performance but lead to significant fluctuations in blade loading. The maximum and minimum blade loading occur when the blade encounters the highest and lowest inflow velocities, respectively. In contrast, the maximum and minimum output power occur slightly after the blades face these corresponding inflow conditions. The spanwise thrust distribution under different sheared inflow conditions shows significant deviations in comparison to the uniform inflow, especially near the blade tips. These variations result in an asymmetric pattern in the large scale wake structure.