Figure 1.
In-plane velocity and streamwise vorticity fields (ωx) from the transverse plane [y, z] behind beetle 2 flying at 7 m s−1 at (a) the beginning of downstroke, (b) mid-downstroke and (c) end of upstroke. Cartoons show approximate attitude of wings and elytra. Vorticity is colour-coded according to the colour bar below and vectors scaled according to the reference vector. Wt, wingtip vortex; Int, interaction vortex; Ev, elytron vortex; Bv, body vortex; Rev, reversed vortex during upstroke.