Computational Fluid Dynamics for Hydrokinetic Turbines

Hydrokinetic energy extraction (HEE) has received increasing attention recently as a sustainable means to alleviate the strain on current energy technologies. HEE extracts kinetic energy, rather than potential (as in traditional hydropower dams), and can be applied to tidal, some ocean, and river energy applications. In this paper, we will focus primarily on river hydrokinetic energy extraction. Although many new types of hydrokinetic devices have been proposed, there has been a dearth of research applying computational fluid dynamics (CFD) to further our fundamental understanding of these systems. Furthermore, the bulk of work in this field continues to draw conclusions for hydrokinetic turbine performance purely based on wind turbine theory. In our previous publications, we have shown that this is, at best, a broad estimate. The comparisons of wind turbine theory to hydrokinetic governing principles and CFD are discussed in this paper. This work presents a CFD analysis for a submerged water wheel turbine for both 2D and 3D cases. Insights into the resulting flow, behavior, and the implications for power extraction and the environmental impact are discussed.