# Comparative Aerodynamic Performance Analysis of Camber Morphing and Conventional Airfoils
## 4 Results
Overall, all configurations of morphed airfoils generate a greater \(C_{L}\) than the unnormed baseline airfoils; morphing the camber by even 1% generates more \(L\). Similarly, for the conventional airfoils, configurations deflected to a higher flap angle generate a greater maximum \(C_{L}\) value. There is a substantial leap in the maximum \(C_{L}\) value for two of the configurations shown in Figure 8, but this is due to the sharper increase of the deflection angle between the two configurations--from \(11.75^{\circ}\) to \(18.5^{\circ}\). In an effort to match the increasing \(C_{L}\) values generated by the morphing airfoils at \(\alpha=0^{\circ}\) by uniformly morphing the camber rate, the conventional airfoils need to deflect more to generate approximately similar \(C_{L}\) values. For a comparative analysis of morphing and conventional airfoils, Figures 7 and 8 are plotted together and set forth in Figure 10. It is observed that the \(L\) profiles of morphed airfoils overlap with the \(L\) profiles generated by deflecting the flap angles of the conventional airfoils. Those configurations where the \(L\) profile of a morphing airfoil closely matches with the \(L\) profile of a conventional airfoil, or presents an approximately similar trend, was set as the basis of comparison. This region over which the \(L\) profiles match is called the \"overlapping region\". These regions extend over a maximum of 10 angles (observed in the 1% camber-morphed and \(1.5^{\circ}\) flap-deflected case) to a minimum of 2 angles (observed in the 7% camber-morphed and \(11.5^{\circ}\) flap-deflected case). More information about the  
Figure 9: Pressure contours of NACA 6412 at \(\alpha=13^{\circ}\) (**a**) and NACA 9412 at \(\alpha=11^{\circ}\) (**b**). (\(Re=76\),630). matching cases, overlapping region, and corresponding morphing and conventional airfoil configurations is stated in Table 1.  
We were able to obtain matching cases for all morphing geometries considered. Morphing the camber rate by 1% generates the same amount of \(L\) as deflecting the flap angle by 1.5\({}^{\circ}\). Similarly, morphing by 2% matches with flap deflection angle of 3\({}^{\circ}\), and likewise all morphed configurations were matched with a configuration of conventional airfoil deflected to a certain flap angle. It is interesting to note that the overlapping region decreases for cases 1 to 7 but expands for case 8 and case 9 as depicted in Table 1.  
Cases 1-9 were carefully identified after matching the \(L\) profiles of a camber-morphed airfoil configuration with a conventional airfoil deflected to a certain flap angle and results of the analysis of their aerodynamic parameters \(C_{L}\), \(C_{D}\), and \(L/D\), along with their geometric configurations are presented in Figure 11, where each column corresponds to one of the nine matching lift cases. From Figure 11A-C, the camber rate and the plain flap deflection angles are increasing (as shown in the geometric configurations in the first row) and the maximum \(C_{L}\) and \(C_{D}\) values also increase across each row. In all nine cases, the camber-morphed configurations generate lesser \(D\) than deflected angles in conventional airfoils. Cases 1, 2, 3, 8, and 9 present with the greatest overlapping regions but since conventional airfoils do not normally deflect to such high angles such as 18\({}^{\circ}\) or 21\({}^{\circ}\), data from the first three cases are presented in Table 2 to validate the benefits of camber morphing. The \(L/D\) ratio was used as the comparison parameter because the aerodynamic efficiency of the aircraft is measured by its maximum \(L/D\) value. The ratio is also seen in calculations regarding the fuel efficiency and endurance of the aircraft [22] and is often set as the maximization factor in optimization studies. Figure 5:0 Overlapping lift plots of various morphing and deflecting airfoil configurations. (\(Re=76\),\(630\)). Figure 5:1 _Cont_.