Two groups of the high speed centrifugal impellers were both designed by the 3-dimensional streamline curvature inverse method and a quasi-3-dimensional inverse method with a slip factor model. One group had different blade numbers

while the other group had different total pressure ratios. The impeller performances were predicted by a commercial computational fluid dynamics (CFD) solver. The design error stabilities of the two methods were compared. The impacts of the splitter blades on the design errors were also studied. The results showed that the 3-dimensional streamline curvature inverse method could realize a proper adjustment to the blade shape according to the blade loading. And compared with the quasi-3-dimensional inverse method

the total pressure ratios of the impellers designed by the 3-dimensional streamline curvature inverse method were generally higher. Therefore

with the increase of blade loading

the design errors of the 3-dimensional streamline curvature inverse method changed much smaller than those of the quasi-3-dimensional inverse method; namely

the design error stability of the 3-dimensional streamline curvature inverse method was much better. In addition

for the quasi-3-dimensional method

the impacts of the splitter blades on the blade design results were much smaller.