Effect of the splitter blade position on the characteristic of high-speed centrifugal compressor

The time marching method is used to solve the control equations and a computational analysis of the flow field in a unshrouded centrifugal impeller is presented. Emphasis is focused on the effect of splitter blade distribution on the flow field and characteristic of the impeller. The numerical analysis is carried out using three-dimensional Navier-Strokes codes with the Baldwin-Lomax algebraic model for closure. The calculations are performed with a central space discrimination scheme, with second and fourth order artificial dissipation terms. The numerical procedure applied a four-order explicit Runge-Kutta scheme, coupled to local time stepping. Numerical results show the blockage at the inlet reduces using the splitter blade. It can get more uniform distribution of the velocity at the impeller outlet when the splitter blade is at location III. The load at the blade pressure side becomes heavier with the shorter splitter blade. For the different azimuthal distribution of splitter blade, impeller IBSA has the highest efficiency.