4 | Discussions

4.1 | TWA Models

To further study the influence of corrugated parameters on the aerodynamic performance of airfoil, the TWA models were modelled with a generalized AP1 as starting point, as shown in Figure 7 (a). The number of corrugations and the corrugation angle were selected as the structural parameters, and the flapping frequency was set as the motion parameter. From Table 3, The average chord length c , the corrugated average height h , and the airfoil thickness n were obtained based on CA models. These values were used still in TWA models. Other settings are as follows:
1. The number of corrugations were set as from 1 to 8 in sequence. Figure 7 (a) shows a model with the corrugation number of 3.
2. Three different corrugation angles were set, namely an acute angle (45°), a right angle (90°) and an obtuse angle (135°), as shown in Figure7 (a).
3. Three different flapping frequencies were used, namely low frequency (55 Hz), medium frequency (65 Hz), high frequency (75 Hz).
4. The flat plate airfoil model (FPA) was designed as the comparative model with the same chord length c and thickness n .
Table 3 Parameters of TWA models