PREDICTION OF THE AERODYNAMIC CHARACTERISTICS OF ANNULAR AIRFOILS

Abstract : A computer program is presented which calculates the aerodynamic characteristics of annular airfoils on an IBM-7090 high-speed computer. A brief review of the theory is also presented. Experimental and computer results indicate that the theory gives reasonable prediction of the lift, induced-drag, and moment coefficients and also of the pressure distribution except when separation is present on the annular airfoil. The computer program can also be used for the design of ducted propellers if an infinite number of blades is assumed.