Effect of angle of attack on flow field and body forces

This quasi-steady state animation shows a Van de Vooren 15% thickness ratio symmetric aerofoil cycling sinusoidally through a -15 deg angle of attack range. The first animation shows the streamlines and pressure field, the second shows the normal forces on the aerofoil, the third the lift component, and the fourth the pressure drag (which integrates to zero in a potential flow). The purpose of this animation was to reveal how the majority of the lift force comes from the upper surface near the