Optimization for Rotor Blades of Tandem Design for Axial Flow Compressors

Abstract

The tandem cascades investigated consist of two retarding cascades closely arranged behind one another. The influences of the flow interference for the pressure distribution at the profiles, for the losses and the outlet angle are discussed. Various cascade configurations are theoretically and experimentally investigated to find out the optimum range of the axial spacing and for the displacement in circumferential direction. An example shows how rotor blades of tandem design can be optimized for minimal profile losses. The aim is to find the optimum configuration for each of the design sections of the rotor blades. A further condition is to avoid additional bending stresses due to centrifugal forces, so that tandem rotor blades can run with relatively high speed.