NACA 1-Series (Series 16)

The NACA 1-series of wing sections developed around 1939 was the first series based on theoretical considerations. The most commonly used 1-series airfoils have the minimum pressure located at the 0.6c point and are referred to as series-16 airfoils. The camber line for these airfoils is designed to produce a uniform chordwise pressure difference across it. In the thin airfoil theory to follow, this corresponds to a constant chordwise distribution of vorticity.

Operated at its design Q, the series-16 airfoil produces its lift while avoiding low-pressure peaks corresponding to regions of high local velocities. Thus the airfoil has been applied extensively to both marine and aircraft propellers. In the former application, low-pressure regions are undesirable from the standpoint of cavitation (the formation of vaporous cavities in a flowing liquid). In the latter, the use of series-16 airfoils delays the onset of deleterious effects resulting from shock waves being formed locally in regions of high velocities.

Series-1 airfoils are also identified by five digits as, for example, the NACA 16-212 section. The first digit designates the series; the second digit designates the location of the minimum pressure in tenths of chord. Following the dash, the first number gives the*design Q in tenths. As for the other airfoils, the last two digits designate the maximum thickness in percent of chord. The 16-212 airfoil is shown in Figure 3.7.