Effect of Blood Circulation in Veins on Resonance Suppression of the Dragonfly Wing Constructed by Numerical Method

To reveal the resonance suppression mechanism of the blood circulation in dragonfly wings, a numerical modeling method of dragonfly wings based on Voronoi diagrams is proposed, and the changes in mass, aerodynamic damping, and natural frequencies caused by blood circulation in veins are investigated. The equivalent mass of blood, boundary conditions, and aerodynamic damping are calculated theoretically. Modal analysis and harmonic response analysis of wing models with different blood circulation paths are performed using the finite-element method (FEM). The vibration reduction ratio δ is introduced to compare the damping efficiency of different mass regions. Finally, a natural frequency testing device is constructed to measure the natural frequencies of dragonfly wings. The results indicate that the shape, mass, and natural frequencies of the dragonfly wing model constructed by numerical method agree well with reality. The mass distribution on the wing can be altered by blood circulation, thereby adjusting the natural frequencies and achieving resonance suppression. The highest δ of 1.013 is observed in the C region when blood circulates solely in secondary veins, but it is still lower than the δ of 1.017 when blood circulates in complete veins. The aerodynamic damping ratio (1.19–1.79%) should not be neglected in the vibration analysis of the beating wing.