Validation of an Axial Flow Blood Pump: Computational Fluid Dynamics Results Using Particle Image Velocimetry

Abstract

A magnetically suspended axial flow blood pump is studied experimentally in this article. The pump casing enclosed a three-blade straightener, a two-blade impeller shrouded by a permanent magnet-embedded cylinder, and a three-blade diffuser. The internal flow fields were simulated earlier using computational fluid dynamics (CFD), and the pump characteristic curves were determined. The simulation results showed that the internal flow field was basically streamlined, except the diffuser region. Particle image velocimetry (PIV) measurement of the 1:1 pump model was conducted to validate the CFD result. In order to ensure the optical access, an acrylic prototype was fabricated with the impeller driven by a servomotor instead, as the magnet is opaque. In addition to the transparent model, the blood analog fluid with the refractive index close to that of acrylic was used to avoid refraction. According to the CFD results, the axial flow blood pump could generate adequate pressure head at the rotating speed of 9500rpm and flow rate of 5L/min, and the same flow condition was applied during the PIV measurement. Through the comparisons, it was found that the experimental results were close to those obtained by CFD and had thus validated the CFD model, which could complement the limitation of the measurement in assessing the more detailed flow fields of the axial flow pump.

Experimental and Numerical Investigation of an Axial Rotary Blood Pump

“…There is some significant backflow at the diffuser on the rotor. A point with nearly stagnating flow of ∼1 Pa WSS (from CFD) can be seen in the flow visualization (Fig. a,b) at the onset of the diffuser.…”

“…The database for axial rotary blood pumps is less broad, though. Some publications exist on velocity profiles derived from PIV measurements on prototype axial blood pumps . Semiquantitative data from oil dot surface flow visualization were presented by Wu et al , also on a prototype mixed‐flow blood pump.…”

Three‐Dimensional Laser Flow Measurements of a Patient‐Specific Fontan Physiology With Mechanical Circulatory Assistance

“…PIV was employed in this study and is a laser flow measurement technique that has been used extensively to examine the internal fluid dynamics of patient‐specific cardiovascular structures, such as arterial bifurcations, carotid arteries, the aorta, arterial stenoses , and of mechanical circulatory assist devices . Previous research has used PIV to investigate the internal fluid dynamics of the TCPC for both idealized and patient‐specific geometries . These studies sought to investigate flow conditions in the TCPC for the purposes of surgically optimizing vessel connections, and thus enhance energy efficiency of the TCPC for improved patient outcomes .…”

Flow‐Field Simulations and Hemolysis Estimates for the Food and Drug Administration Critical Path Initiative Centrifugal Blood Pump

“…By blending two of the most popular and robust turbulence models (the standard k ‐epsilon and the standard k ‐omega), the SST k ‐ω model is less sensitive to free‐stream turbulence properties and large, adverse pressure gradients than traditional models, which results in more accurate flow field predictions for low‐Reynolds‐number turbulence . This model has previously been used with some success to predict turbulent flow in a variety of complex systems, including in an axial blood flow pump with turbulence near the impeller tip, as examined by Su et al .…”