Numerical and Experimental Investigation on the Influence of Blades Gap Flow on Axial Blood Pump Performance

The axial blood pump body primarily contains the Inlet Guide Vane (IGV), Rotor Impeller (RI), Outlet Guide Vane (OGV) and pump casing. There must be gaps between rotor blade tip and pump casing or between OGV blade root and rotor hub for the impeller rotating in the pump. The flow characteristics inside an axial blood pump with different blade gaps were numerically simulated and analyzed. Hydraulics experiments were conducted to verify the numerical results. The results show that the pump efficiency decreased slowly when the OGV blade gap increased from 0.1 mm to 0.3 mm, but quickly when the rotor blade gap increased from 0.1 mm to 0.3 mm. The hydraulics characteristic results indicate that the pressure rise and efficiency are mainly influenced by the rotor blade gap. The OGV blade root gaps have little influence on the decrease of pressure rise and efficiency. The novel configuration with uneven blade gaps inside the pump result in improved hydraulics and hemolytic performance compared with the similarly sized configuration with even blade gaps.