EXPERIMENTAL AND NUMERICAL INVESTIGATION OF THE FLOW THROUGH CASCADES

Abstract

Investigation of the flow through two-dimensional cascade is considered in the present work, the relation between cascade geometric and aerodynamic parameters is handled both experimentally and theoretically. Experiments have been performed on an isolated airfoil and a cascade of airfoils. The pressure distribution along the airfoil contour was measured at different incidence angles, for the isolated airfoil, and different stagger and inlet flow angles, for the cascade; NACA 0015 blade section is employed in the measurements. The theoretical approach to calculate the frictionless flow through two-dimensional cascades was conducted using the singularity method of Schlichting, the airfoil is replaced by distributions of vortices, and sources and sinks. The direct problem is considered i.e. determination of the vortex and source distributions related to a prescribed profile geometry. A computer program, in Basic language, is developed forthat purpose. The measured pressure distributions along the blade suction and pressure sides were compared with the computed results. Moreover, the present prediction is compared with other experimental data that covers a variety of geometrical configurations and flow conditions. The comparison shows that the present computer code is stable and efficient; it is economical and yields good engineering results.