Six numerical examples are presented for steady, two-dimensional, compressible, nonviscous flow in centrifugal compressors with straight blades. A seventh example is presented for incompressible flow. The solutions also applye to radial-flow turbines with rotation and flow direction reversed. The effects of variations in following parameters were investigated: (1) flow rate, (2) impeller-tip speed, (3) variation of passage height with radius, and (4) number of blades. The numerical results are presented in plots of the streamlines, constant Mach number lines, and constant pressure-ratio lines. Correlation equations are developed whereby the flow conditions in any impeller with straight blades can be determined for all operating conditions.