An Eleven Parameter Axial Turbine Airfoil Geometry Model

Abstract

The mathematical derivation, and FORTRAN code, of a comprehensive but easy to use geometry model for axial flow turbine nozzles and rotors is presented. To uniquely define an airfoil on a cylinder the acrodynamicist need only specify the number of blades, and at each radius of interest: the axial and tangential chord, throat, 1mcovered turning, leading and trailing edge radii, inlet and exit blade angles, and inlet wedge angle. Default values exist for six of these geometric variables, which proves useful when starting a design. Both the suction and th8 pressure surfaces are described entirely by analytical functions. Sample airfoils are included that demonstrate the effect of each parameter upon blade shape.