Formulation of a New Approach to Design Cascades Using Inverse Method: a Theory of Incompressible Inviscid Two-Dimensional Flow

The fluid behavior in the profile cascade of turbomachinery is often studied using direct computational methods for the numerical solution of Navier-Stokes equations. In this paper a new methodology is presented to design the blade row using the inverse method from fluid mechanic equations. The formulation is described, and the results of its application are presented in relation to cascade geometric shape drawing and to velocity and pressure distributions in the absolute and relative flow-field locations. A theoretical model of an inviscid, incompressible, irrotational steady flow around a blade row is presented. A design methodology is described in relation to the developed model. Nonlinear algorithms were programmed in a computation code to define the values of the characteristic coefficients of the present equations in relation to known Q, h, and n machine parameters. Some numerical results of an application are shown.