Host: The Japan Society of Mechanical Engineers
Name : [in Japanese]
Date : November 19, 2024 - November 20, 2024
In recent years, there is increasing anticipation for the development of unmanned micro air vehicles (MAV) capable of exploring narrow spaces within collapsed buildings. Attention has focused on insect-inspired flapping wing MAV, which exhibits excellent aerodynamic performance and stability at small scales. In particular, configurations with four flapping wings as dragonflies are referred to as tandem flapping wing configurations. There are various flight mechanisms within the tandem flapping wing flight, and these have not yet been fully clarified. The objective of this study is to conduct computational fluid dynamics (CFD) analyses around the tandem flapping wings and to investigate the influence of the positional relationship between the fore and rear wings, determined by the distance and the phase difference between the fore and rear wings. In this study, we conducted analyses by varying the distance, which is normalized by the chord length from 0.2 to 1.0 in 0.1 increments and the phase difference between the fore and rear wings from 0 to 360 deg in 10 deg increments. CFD analyses were conducted based on the three-dimensional incompressible Navier-Stokes equations and continuity equation. This study focused on a hovering condition without uniform flow. The obtained results indicated that the thrust force of the rear wing was sensitively influenced by positional relationship between the fore and rear wings. Result showed that the phase difference changed the effects obtained from negative pressure regions formed in the lower side of the fore wing. The smaller the phase difference, the larger the effects from the negative pressure regions when the rear wing follows the fore wing, and the highest thrust force was obtained at the condition of φ=30 deg. In addition, higher thrust force was generated with smaller distance between the fore and rear wings, and the highest thrust force was obtained at the condition of d= 0.2.
