Effect of Rotor Blade Angle and Clearance on Blood Flow through a Non-pulsatile, Axial, Heart Pump

This study involves CFD simulation of blood flow through a non-pulsatile, axial pump consisting of a complex multisectioned impeller with rotating and stationary components, and a stationary housing. We use a particlebased method, Smoothed Particle Hydrodynamics (SPH), to investigate the effects of varying the impeller blade pitch angle and the gap size between the rotor and housing. Regions of flow reversal are identified at the front and tail end of the pump. We show that the impeller blade inclination affects pump performance and the level of shear-related blood damage. The optimal blade angle was found to be for a pitch angle of 0. The pressure rise across the pump, the flow rate and the shear losses are all shown to be affected by the inclusion of a rotor-housing clearance. This leads to flow losses that reduce the efficiency of the pump but also reduce the viscous energy losses in the pump.