Bio-inspired aerofoils for small wind turbines

Abstract

This paper investigates the effectiveness of modifying the design of wind turbine blades for small wind turbines. Taking inspiration from nature, the two modifications explored were spanwise corrugations of the blades inspired by a dragonfly's wing structure, and flexible blades inspired by the shape-morphing of birds and insect wings that adapt to the air conditions. Two types of corrugations were tested in a wind tunnel with the results that the corrugated nature appeared to have desired effects on delaying stall by 4° and reduced the detriment of post-stall behaviour. In addition, the corrugated skin displayed similar characteristics to the control aerofoil, with a small reduction in the peak lift to drag ratio of 7.3%. In the second section, a rigid turbine blade was compared a semi-flexible and fully flexible blade by altering the Young's modulus using the QBlade simulation tool. Although, spanwise deflection was high in the flexible blade, a reduction in the peak stresses was shown.

Design Analysis of Vertical Axis Wind Turbine Blade Using Biomimicry

“…The simulations under XFOIL, rotor-turbine DMS and LLT under Q-blade software of the Maple-Wing blade plus winglet edge tips with cross-section of a Corrugated Dragon vein FX 63-137 foil showed an overall performance improvement and had the characteristics to provide better power and torque output under dynamic wind speed ranges with better efficiency [7,9]. The biomimicry implementation over the foil and blade also proved beneficial in maintaining low-stress density and simplistic design, these advantages can be leveraged in large scale wind energy projects such as wind farms and harnessing oceanic winds as well as an energy supply alternative for small scale household appliances and even commercial equipment as a secondary energy source.…”

“…Bio-mimicable features with aerodynamic capabilities worth incorporating into the dynamic VAWT blades using base foil FX 63-137 as the standard reference foil included the Golden Eagle wing, Dragon Fly wing, Maple seed leaf. Whereas the Golden Eagle wing structure and [7][8][9] Dragonfly vein structure are quite suitable for the sizable blade cross section, hence their design features were suitable for adding on the base foil [Figures 5, 6 and 7]. The corrugated pattern of the veins on dragon fly's transparent wings enables dragon flies to maintain fixed altitudes and swift flight trajectories for long durations of time without intervals helping them migrate great distances in short time periods.…”

“…It fit the steady flow conditions with performance improvements at high pitch angles using secondary wing structure [8]. Flexible blade structure made of bamboo laminate with dragonfly vein corrugated add on was simulated and it gave the advantage of delayed stall and better adaptation over similar base foil structure [9]. Meana-Fernández et al [10] presented numerical work in the paper where they explained the important factors necessary to consider using JAVA foil.…”

Nature-Inspired Designs in Wind Energy: A Review

“…In their study, Mulligan [100] investigated the potential of modifying small wind turbine blades by focusing on two key modifications: spanwise corrugations, mimicking a dragonfly's wing structure, and flexible blades, inspired by the adaptive shape-morphing of bird and insect wings. The research concludes that these innovative turbine designs, especially corrugated airfoils, and bamboo laminates, can enhance performance, particularly in areas with limited facilities.…”

Karakteristik Aerodinamika Sudu Turbin Angin Bio-inspired Menggunakan Simulasi CFD

“…Penelitian selanjutnya dilakukan oleh Mulligan yang meneliti tentang turbin angin dengan rotor beralur terinspirasi dari sirip ikan paus. Hasil penelitian menunjukkan bahwa desain tersebut dapat meminimalisir stall, mengurangi perbandingan lift dan drag [4]. Penelitian selanjutnya dilakukan oleh Talarico mendesain bio-inspired energy harvester, berupa turbin angin dengan model flapping airfoil.…”