NACA 0009

• NACA 0009-PT (Fig. 12.60)

The NACA four-digit symmetric airfoils are often used on tail surfaces, most commonly the stabilizer. As expected, the drag of the 9% thick NACA 0009 is lower than the 12% symmetric J5012. It is interesting to note, however, that the lift range of the thinner NACA 0009 is on a par with the J5012.

Again, as with the J5012, there is a deadband in lift about 0°, but as shown in Figs. 12.61 the deadband for the NACA 0009 is worse than the J5012. As mentioned before, any substantial nonlinearity in the lift-curve slope is caused by some type of laminar or turbulent separation. Also, between approximately — 2° and 2°, the lift characteristics are slightly asymmetric. For the NACA 0009 at low Rn’s, a long, thin bubble forms on both the upper and lower surfaces. Any slight asymmetries present (either in contour or surface finish) will alter the boundary layer behavior, thereby affecting the symmetry of lift. In fact, as Fig. 10.22 reveals, the NACA 0009-PT is not perfectly symmetric which leads to the asymmetric lift and drag characteristics about 0°.

Also see: SD8020, NACA 64A010, J5012 Digitizer plot: Fig. 10.22 Polar plot: Fig. 12.60 –

Lift plot: Fig. 12.61

Thickness: 9.00% Camber: 0.00%