The papers selected include experimental and computational studies on Wind Energy, Innovative Wind, and Hydro Energy Technology, Assessing the Effect of Coriolis Acceleration on the Coherent Structures in the Wake of a Wind Turbine, Design Guidelines for Arrays of Closely Spaced Darrius Turbines, Investigations on Effects of Inflow Turbulence on Vortex-Induced Vibrations of a Wind Turbine Airfoil With the Wake Oscillator Model, a Multi-Objective Optimization Framework for Offshore Wind Farm Design in Deep Water Sea, a Wind Speed Forecasting Method Using a Gaussian Process Regression Model Considering Data Uncertainty, Design and Implementation of an Experimental Test Bench for the Study of Active Flow Control in Scale Wind Turbines, Optimum Design of Scaled-Down Wind Turbines Based on Field Data, Experimental and Simulation Investigation of J-Shaped and Kammtail Virtual Airfoils in Small-Scale Horizontal Axis Wind Turbines, and Study of a Cavitation Treatment in Kaplan Hydro-turbine.

The editorial board for this Special Section raises awareness of the impact and application of wind and hydro turbines while helping to raise the visibility of the ASME Journal of Fluids Engineering.

Finally, we thank Professor Francine Battaglia, the Editor-in-Chief of the ASME Journal of Fluids Engineering, for allowing us to edit the Special Section on a high-impact topic. We also thank Ms. Elizabeth Bruce, the Assistant of the Editor-in-Chief, for her technical support. Finally, we thank all the authors and reviewers who contributed to this Special Section.