**4.5 Turbulent kinetic energy**

**Figure 13** shows the distribution of the turbulent kinetic energy of the curved blade turbine. The turbulent kinetic energy is dimensionless by the square of the tip velocity. According to these results, the turbulent kinetic energy is maximum at the blade tip, and it decreases progressively moving away from the blade. As it was found in the previous sections, the convex blade dissipates the highest energy in the flow. The energy produced by the flat blade decreases by 37% and by 27% for the concave configuration. For the staged system (**Figure 14**), the maximum turbulent kinetic energy is localized between the two blades at the same direction as the trailing vortices. In addition, the turbulent kinetic energy is larger at the association of the concave blade than the convex blade.
