Abstract: Based on the improvement of S1 and S2 codes, a quasi-3D solution for the impeller flow-field has been completed in present study. The quasi-3D solution is obtained by use of iteration between a number of S1 stream filaments and a single mean S2 stream filament. The computation results for a given impeller show that the convergence solution can be obtained merely through five or six iteration cycles. And the accuracy of iteration convergence is quite high. The accuracy of Mach num and S2 is automatically ber can reach 3％ in a given computation example. The process of iteration between S1 carried out and no artificial interference is required. The preprocess and post-process are sophisticated in present software system. Using ready-made drawing-software, the computation results can be transformed into figures or pictures on computer screen or plotter directly. The present software system has been successfully applied to engineering design of centrifugal compressor.

Key words: 3D solver, Centrifugal compressor, arc-blade, axial vortex, cut size, rotor-cage, turbo air classifier