Fig. 4. Composite wake velocity and vorticity plots of the near wake in the streamwise plane [x, z] for the inner wing (lx) at flight speeds of 2, 3, 5 and 7 m s^–1. At 2 m s^–1 the images show double start vortices (white arrows) and a single stop vortex. For further explanation, see Fig. 3.