Fig. 4. Spanwise vorticity, _y(x,z) for two fixed wings, shown at midspan. The left column shows the wake for a thin cambered plate, with circular arc, and the right column is for the Eppler 387. The silhouettes are shown below. The top row is for a measurement station where the left margin is at x=1c (immediately behind the trailing edge), and the symmetric colour bar is scaled to ±8U/c. The bottom row is taken at x=10c, and the colour bar is scaled to ±2U/c. The field of view is 3.2cx1.5c in x and z. The aerofoils are at fixed angle of attack, =4°, and the chord Reynolds number is 11.7x10³.