Citation: Yang, W.-B.; Zhou, J.; Xiao,
W.-H.; Peng, S.-J.; Hu, Y.-F.; Li, M.;
Wu, H.-C. Effect of Conical Spiral
Flow Channel and Impeller
Parameters on Flow Field and
Hemolysis Performance of an Axial
Magnetic Blood Pump. Processes 2022,
10, 853. https://doi.org/10.3390/
pr10050853
Academic Editors: Arkadiusz Gola
and Patrik Grznár
Received: 15 January 2022
Accepted: 19 April 2022
Published: 26 April 2022
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Article
Effect of Conical Spiral Flow Channel and Impeller Parameters
on Flow Field and Hemolysis Performance of an Axial Magnetic
Blood Pump
Wei-Bo Yang
1
, Jian Zhou
1
, Wei-Hu Xiao
1
, Si-Jie Peng
1
, Ye-Fa Hu
1,2
, Ming Li
1
and Hua-Chun Wu
1,2,
*
1
School of Mechanical and Electronic Engineering, Wuhan University of Technology, Wuhan 430070, China;
yangwb@whut.edu.cn (W.-B.Y.); whutdrz@whut.edu.cn (J.Z.); 259653@whut.edu.cn (W.-H.X.);
305117@whut.edu.cn (S.-J.P.); huyefa@whut.edu.cn (Y.-F.H.); tuxing@whut.edu.cn (M.L.)
2
Hubei Provincial Engineering Technology Research Center for Magnetic Suspension, Wuhan 430070, China
* Correspondence: whcwhut@whut.edu.cn
Abstract:
For a blood pump, the blood flow channel and impeller parameters directly affect the
performance of the pump and the resulting blood circulation. The flow channel in particular has
a great impact on the hydraulic performance of the pump (e.g., flow and pressure), which directly
determines the overall performance of the blood pump. Traditional bearing-supported blood pumps
can cause mechanical damage to blood cells, leading to hemolysis and thrombosis. In this study,
therefore, we designed a conical spiral axial blood pump with magnetic levitation. The blood pump
was supported by electrodynamic bearings in the radial direction and electromagnetic bearings in
the axial direction. The impeller and the front and rear hubs were integrated to minimize blood
stagnation and reduce the formation of thrombosis. The hub had a conical spiral flow channel
design, which not only reduced the size of the impeller but also increased blood flow and pressure
while meeting the design requirements. Computational fluid dynamics (CFD) analysis was used
to analyze the flow field of the axial blood pump, a power function model was used to establish a
hemolysis prediction model, and the particle tracking method was used to obtain the flow trajectories
of individual blood cells, thereby predicting hemolysis-related performance of the blood pump. The
simulation results showed that the main high shear stress area in the blood pump was located in
the impeller inlet and the clearance between the top of the impeller and the inner chamber of the
blood pump. When the hub taper angle of the blood pump was 0.72
◦
and the clearance was 0.3 mm,
the average hemolysis prediction value was 0.00216. This prediction value was smaller than that of
traditional axial blood pumps. These findings can provide an important reference for the structural
design of axial blood pumps and for reducing the hemolysis prediction value.
Keywords:
blood pump; hemolysis performance; axial flow; magnetic levitation; particle tracking
method
1. Introduction
Heart disease is currently a major cause of death. About one-fifth of heart disease
cases each year eventually develop into heart failure [
1
,
2
]. Due to a shortage of donors,
most patients with heart disease cannot be effectively treated right away, but a ventricular
assist device (VAD) can usually buy time for patients until a suitable donor is found
[3,4]
.
However, when the blood pump is operating in the human body, if the incidental de-
struction of red blood cells by the pump exceeds the renewal rate of red blood cells in
the body, the ability of oxygen transmission and carbon dioxide removal can be seriously
affected, resulting in insufficient oxygen supply to organs and tissues, and even death [
5
,
6
].
Currently, the axial blood pump has evolved to a third-generation magnetic design [
7
,
8
].
Turbulent-like hemodynamics with prominent cycle-to-cycle flow variations have received
increased attention as a potential stimulus for cardiovascular diseases [
9
]. Although the
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