A very small centrifugal pump, fully supported by magnetic bearings, is bei
ng developed for use as a ventricular assist device to be implanted in huma
ns. In this paper, we apply computational fluid dynamics to model the blood
flow to aid in the design of the ventricular assist device. The flow of bl
ood through the pump has been modeled using computational fluid dynamics (C
FD) software that is commercially available from AEA Technology, UK. The fl
ow regions modeled in Version 3 of the Continuous Flow Ventricular Assist D
evice (CF3) are the fully shrouded four bladed impeller and the two clearan
ce regions around the impeller that are bounded by the pump hub and shroud.
This paper describes the geometry and computational grids developed for th
e flow regions, and the equations of motion for the blood flow are develope
d. The overall numerically-evaluated flow rates and head rise have similar
trends to the flow parameters experimentally measured, indicating that futu
re pump designs can be effectively modeled numerically before being constru
cted and tested. Numerical solutions are presented and compared with experi
mentally-obtained overall pump performance results. These solutions are use
d to predict shear stress levels to be experienced by the blood flowing thr
ough the pump, and if is predicted that hemolysis will be insignificant. Th
e solutions also indicate no regions of flow stagnation that can be a sourc
e of thrombosis in pumps. The calculations provide a viable design method t
o achieve improved efficiency in future versions of this pump.