A New Technique for Analysis of Unsteady Aerodynamic Responses of Cascade Airfoils with Blunt Leading Edge. Unsteady Aerodynamic Responses of the Cascade in Incompressible Flow.

Abstract

Unsteady aerodynamic responses of cascade airfoils with a blunt leading edge, which are subjected to incident rotational and irrotational fluctuations, are analyzed by use of the method developed in the previous paper of Funazaki and Kakudate. Since some difficulties in the imposition of the boundary condition have been pointed out in that paper, most of the efforts in this study are devoted to refinement of the method of the boundary condition imposition on the inlet/outlet and periodic boundaries by employing the analytical solutions in the upstream/downstream far-fields. Although the method presented in this paper could be applied to compressible flow problems, numerical examples employed this time are limited to incompressible flow cases. Obtained results then show the usefulness of the method, and also reveal some of the notable features of the unsteady flow field induced within the blade-to-blade passage vividly.