The Role of Elytra in Beetle Flight: I. Generation of Quasi-Static Aerodynamic Forces

We conducted a comprehensive study to investigate the aerodynamic characteristics and force generation of the elytra of a beetle, Allomyrina dichotoma. Our analysis included wind tunnel experiments and three-dimensional computational fluid dynamics simulations using ANSYS-CFX software. Our first approach was a quasi-static study that considered the effect of induced flapping flow due to the flapping motion of the fore-wings (elytra) at a frequency of around 30 Hz to 40 Hz. The dihedral angle was varied to represent flapping motion during the upstroke and downstroke. We found that an elytron produces positive lift at 0° geometric angle of attack, negative lift during the upstroke, and always produces drag during both the upstroke and downstroke. We also found that the lift coefficient of an elytron does not drop even at a very high geometric angle of attack. For a beetle with a body weight of 5 g, based on the quasi-static method, the fore-wings (elytra) can produce lift of less than 1% of its body weight.