A Preliminary Study on the Performance of a Flexible Sheetlike Blade Wind Turbine Inspired by the Borneo Camphor Seed

The Borneo Camphor with its scientific name, Dryobalanops aromática is a type of tropical tree that possesses winged seeds that gyrate for propagation. The Borneo Camphor seed is unique as it consists of 5 pre-coning flexible wings which allow it to track the oncoming relative wind and expands its rotor diameter due to centrifugal forces induced by rotation. This subsequently increases drag which reduces its terminal velocity, furthering its propagation distance from the mother tree. The mechanical and flight characteristics of the Borneo Camphor seed was mimicked into the design of a novel biomimetic downwind, flexible, pre-coning and sheetlike blades wind turbine. This biomimetic wind turbine features the abilities to track the wind direction passively due to its pre-coning blades, enables cheap fabrication method due to the lightweight polypropylene sheet, easy transport and packaging due to the sheetlike blades, and passive extreme wind protection system which will be triggered by coupling the collapsible blades and also internal mechanical brakes. A preliminary study was conducted to predict the power performance of a 0.7 m diameter biomimetic wind turbine by using Fluid-Structure Interaction (FSI) simulation while the yaw recovery speed was tested by using a simple blower fan setup with a free yawing wind turbine prototype. The FSI prediction shows that the maximum power coefficient, C_{P_max} was 22.9% higher than a flat plate benchmark turbine at a wind speed of 3 m/s. The wind turbine prototype rotor was able to turn from 90 to 0° yaw error in approximately 1 s at an averaged wind speed of 3.73 m/s. This preliminary result shows the potential of the biomimetic wind turbine in distributed wind applications such as green energy housing, portable wind turbines, and temporary off-grid wind energy systems.