The Calculation of Deviation Angle in Axial-Flow Compressor Cascades

Abstract

The deviation angles of axial flow compressor cascades have been predicted by solving the Reynolds averaged fully turbulent Navier-Stokes equations. A finite element method has been used. To close the problem an algebraic eddy viscosity turbulent model has been chosen. The introduction of the idea of vorticity to the governing equation enables the establishment of a relation between the entropy and the vorticity fields, and the vorticity transport differential equation in the stream function-vorticity method is replaced by a differential operation. A series of calculations have been carried out to examine the influence of cascade geometry on the devotion angle. Very good agreement has been obtained for small angles of incidence with the correlations produced by NASA and using Carter’s rule. Good agreement has also been shown for the variation of deviation angle with the angle of incidence with the experimental data of Felix and Emery, as well as for the distribution of the pressure coefficient along the blade axial chord.