Inherent in the majority of the theoretical performance models to date is the need for airfoil data banks which provide lift, drag, and moment coefficient values as a function of Mach number, angle-of-attack, maximum thickness to chord ratio, and Reynolds number. With the renewed interest in propellers as means of obtaining thrust and fuel efficiency in addition to the increased utilization of the computer, a significant amount of progress was made in the development of theoretical models to predict the performance of propeller systems. The program produces plots of the airfoil nondimensional ordinates and a punch card output of ordinates in the input format of a readily available program for determining the pressure distributions of arbitrary airfoils in subsonic potential viscous flow.Īerodynamic data banks for Clark-Y, NACA 4- digit and NACA 16-series airfoil families
Sample calculations for an NACA 63(2)-015 airfoil showed an annual energy output increase of 17-27 percent, depending on rotor solidity, compared to an NACA 0015 airfoil.ĭevelopment of a computer program to obtain ordinates for NACA 4- digit, 4- digit modified, 5- digit, and 16 series airfoilsĪ computer program developed to calculate the ordinates and surface slopes of any thickness, symmetrical or cambered NACA airfoil of the 4- digit, 4- digit modified, 5- digit, and 16-series airfoil families is presented. Results indicated that NACA 6-series airfoils yield peak power coefficients as great as NACA 4- digit airfoils and have broader and flatter power coefficient-tip speed ratio curves. Performance estimates were made using a blade element/momentum theory approach.
Ten different airfoils, having thickness-to-chord ratios of 12, 15, and 18 percent, were studied.
Analysis was limited to curved-bladed machines having rotor solidities of 7-21 percent and operating at a Reynolds number of 3 x 10 to the 6th. The aerodynamic efficiency of Darrieus wind turbines as effected by blade airfoil geometry was investigated. Comparison of NACA 6-series and 4- digit airfoils for Darrieus wind turbines