Laser measurements and 3D-viscous calculations were performed to verify the design of a 30deg. backswept impeller with advanced blade geometry and high design rotor pressure ratio (πt12=4.7:1). Both, measured and calculated results are in good agreement. They are pointing to a low velocity area inside the rotor that vanishes toward the exit resulting in comparatively smooth discharge velocity profiles. The rotor geometry used for the verification is released. The application of the 3D-viscous calculation code now embedded in an impeller design procedure and its support by a number of pre- and postprocessing programs is described.Copyright © 1989 by ASME