Centrifugal compressors are widely used in aeronautics, power and energy, chemical metallurgy-and many other industries for higher stage -pressure ratio and superiors manufacturing technique. The model stage studied in this thesis was designed by Nuovo Pignone in the 70s last century. The efficiency of such a model stage is usually 10% lower than the modern state-of-art products in current market and thus at a very disadvantage position in the competitive market, as the design method is out-of-date now.Base...