Abstract: The implicit method which has second order accuracy in the time and space is proposed. Using the method, the 3D steady viscous flow field in turbomachinery with curved blades is simulated. The various shock waves and vortexes are captured. Through the comparison of vortex structure in straight cascade, another main reason of loss decreasing in positively curved cascade is found. That is the passage vortex which play an important role in secondary flow can be limited in a stable range in positively curved cascade.

Key words: Curved blade, Flow field, Implicit method, Passage vortex, TVD Scheme