Abstract
Heart-lung equipments are useful to save life of acute heart failure and respiratory distress patients. To realize a compact heart-lung equipment, the pump that generates high pressure with low flow is appropriate. To meet the purpose, we have been developing a novel centrifugal pump named sequential flow pump (SFP).The SFP has a structure that centrifugal force is given sequentially two times to the fluid with a single impeller. Since the SFP adopts single pivot or hydrodynamic bearing, axial balance of the impeller is essential. In this study, axial balance of the impeller was examined using computational fluid dynamics (CFD) analysis and actual models. In the experimental model, the impeller could be balanced up to 3200 rpm of rotational speed. However, stability was not so good.To improve the stability, a new model, in which basic simple straight-pass impeller could be balanced up to 1900 rpm of rotational speed, was developed. Various impellers were investigated in this pump. The results showed that the impeller having special shape in periphery would be excellent.
