The Theoretical Induced Deflection Angle in Cascades Having Wall Boundary Layers

A theoretical analysis is presented which employs a lifting-line theory assuming incompressible, nonviscous flow to determine the induced deflection angle in two-dimensional cascades having wall boundary layers. Two correction factors are derived for the deflection angle of the idealized infinite cascade: one that accounts for the induced deflection due to the trailing vortex system in the wall boundary layer, and the other that accounts for the decrease in total circulation of the bound vortex system. Plots are included which show the effect of blade length, boundary-layer thickness, and the number of blades in cascade on the deflection angle of several typical cascade configurations.