Abstract
In an ultra micro centrifugal compressor (UMCC), the applicability of the two-dimensional blade has been investigated for the consideration of the productivity in the downsizing of impeller. On the other hand, the restriction of processing technology for the downsizing of compressor system relatively enlarges the size of tip clearance. Moreover, UMCC is required to operate at high rotational speed to establish the gas turbine cycle. Therefore, the blade thickness is enlarged by considering the stress acting on the blades due to the centrifugal force. In this study, the flow in the centrifugal impellers with the two-dimensional blade was analyzed numerically to investigat e the influence of the downsizing of compressor system on the similitude of aerodynamic performance. The computed results clarified that the compressor performance is remarkably decreased due to the relatively enlarged sizes of tip clearance and blade thickness by the downsizing of systems.
