Exploring biomimicry in wind and hydrokinetic turbine design: bridging nature and engineering.

Nature has remained one of the key sources of inspiration for human technology. While striking for higher efficiency, design improvements in power-generating turbines have started to reach a saturation point. Biomimicry- learning from nature, has great potential for significant performance improvements. This paper provides a comprehensive review of the current trends in research of bioinspired technology on wind and hydrokinetic turbines. The aim is to identify the most effective bioinspired methods and the factors affecting the turbine performance. Various methods adopted are inspired by animals and plants and their interaction with fluid to enhance aero/hydrodynamic properties. These promising methods include the humpback whale tubercle and bird wing, where flow characteristics can be improved such as delaying the stall conditions and suppressing flow separation. Methods inspired by dragonfly wings, sea pen leaves, and plant seeds showed substantial merit for operating at low wind speeds, as a better glide ratio, enabling them to be suitable for low wind speed turbines. Furthermore, additional surface and structural modifications are explored, and their contributions are discussed in this paper. Various biomimicry methods were compared and critically analysed. This paper closes with a brief overview of future development options.