Development of Bio-inspired Perforated Flapping Wings

Ornithopters have received considerable attention in recent years due to their potential applications in various fields. In this study, we propose a novel approach to ornithopter wing design aimed at improving lift and thrust generation while reducing negative lift during the upstroke. To achieve this, the wing design mimics the twisting of feathers in birds during the upstroke, which allows air to pass through the wing and reduces negative lift. The proposed wing design includes multiple converging holes that increase the volume of air passing through them, resulting in an increase in the outlet air velocity during the upstroke. Additionally, aligning the holes with the direction of flight allows for the generation of positive thrust during the upstroke. The effectiveness of the proposed wing design was confirmed through experimental results obtained using a six-component force transducer. The experimental results showed a significant improvement of around 13.5% and 44.6% in lift and thrust gain coefficients respectively generated by the proposed wing design, demonstrating its potential for the development of more efficient and effective ornithopters. This approach provides a new direction for ornithopter wing design and offers potential for applications in various fields.