Fig. 10. Comparison of the averaged measurements of instantaneous drag forces with the cross-flow vortex model. The steady fin measurements are also included. Blue and green data indicate tests with a 20 or 30 cm span, respectively. The inset expands the data up to an angle of attack of 20° where stall occurs in the steady case (Fig. 9) to clarify that the cross-flow vortex model does not account for viscous drag.