Figure 2.

Force coefficients. Parameter maps for (a) drag, (b) lift and (c) net force coefficients as functions of angle of attack and flexural stiffness EI. In each plot, the small filled circles indicate experimentally measured values of lift and drag coefficients with shaded interpolated values in pseudo-colour. Overlying the pseudo-colour plots are the related contour plots (white) for force coefficients. The same data are represented as (d) drag, (e) lift and (f) net force coefficient versus angle of attack. The angle of attack in these experiments varies from −9° to 90° in steps of 4.5°. In (d), (e) and (f), the curves for various materials are displayed in different colours and different symbols for each wing material. (g) The aerodynamic polar plots are represented with various symbols to indicate each wing material. A list of the symbols and corresponding materials is given in the inset in order of increasing rigidity. These symbols are consistent in all subsequent figures.