PIV experimental study on the flow field characteristics of axial flow blood pump under three operating conditions

The splitter blade can effectively optimize pump performance, but there is still insufficient research in blood pumps that cover both hydraulic and hemolysis performance. Thus, the aim of this study was to investigate the effect of key factors related to splitter blade on the performance and flow field of axial flow blood pump. In this study, the number of splitter blades, the axial length, and the circumferential offset were chosen as three objects of study. An analysis of the flow field and performance of the pump by orthogonal array design using computational fluid mechanics was carried out. A set of hydraulic and particle image velocimetry experiments of the model pumps were performed. The result showed that the pump had greater hydraulic performance without sacrificing its hemolytic performance when it had two splitter blades, the axial length ratio was 0.6, and the circumferential offset was 15°. Based on these reference data, the splitter blade may contribute to greater hydraulic performance of the pump and cause no side effect on the velocity distribution of the flow field. This finding provides an effective method for the research, development, and application of structural improvement of the axial flow blood pump.

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Analysis of flow field and hemolysis index in axial flow blood pump by computational fluid dynamics–discrete element method

The International Journal of Artificial Organs ◽

10.1177/0391398820917145 ◽

2020 ◽

Vol 44 (1) ◽

pp. 46-54

Author(s):

Lizhi Cheng ◽

Jianping Tan ◽

Zhong Yun ◽

Shuai Wang ◽

Zheqin Yu

Keyword(s):

Fluid Dynamics ◽

Computational Fluid Dynamics ◽

Numerical Calculation ◽

Flow Field ◽

Discrete Element Method ◽

Axial Flow ◽

Discrete Element ◽

Blood Pump ◽

Axial Flow Blood Pump ◽

Element Method

To fully study the relationship between the internal flow field and hemolysis index in an axial flow blood pump, a computational fluid dynamics–discrete element method coupled calculation method was used. Through numerical analysis under conditions of 6000, 8000, and 10,000 r/min, it was found that there was flow separation of blood cell particles in the tip of the impeller and the guide vane behind the impeller. The flow field has a larger pressure gradient distribution, which reduces the lift ratio of the blood pump and easily causes blood cell damage. The study shows that the hemolysis index obtained by the computational fluid dynamics—discrete element method is 4.75% higher than that from the traditional computational fluid dynamics method, which indicates the impact of microcollision between erythrocyte particles and walls on hemolysis index and also further verifies the validity of the computational fluid dynamics–discrete element coupling method. Through the hydraulic and particle image velocimetry experiments of the blood pump, the coincidence between numerical calculation and experiment is analyzed from macro and micro aspects, which shows that the numerical calculation method is feasible.

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COMPARISON AND EXPERIMENTAL VALIDATION OF TURBULENCE MODELS FOR AN AXIAL FLOW BLOOD PUMP

Journal of Mechanics in Medicine and Biology ◽

10.1142/s0219519419400633 ◽

2019 ◽

Vol 19 (08) ◽

pp. 1940063

Author(s):

SHUAI WANG ◽

JIANPING TAN ◽

ZHEQIN YU

Keyword(s):

Velocity Field ◽

Flow Field ◽

Axial Flow ◽

Turbulence Models ◽

Internal Flow ◽

Reynolds Stress Model ◽

Blood Pump ◽

Axial Flow Blood Pump ◽

Standard Formula ◽

Text Model

Computational fluid dynamics (CFD) has become an essential tool for designing and optimizing the structure of blood pumps. However, it is still questionable which turbulence model can better obtain the flow information for axial flow blood pump. In this study, the axial flow blood pump was used as the object, and the influence of the common turbulence models on simulation was compared. Six turbulence models (standard [Formula: see text]–[Formula: see text] model, RNG [Formula: see text]–[Formula: see text] model, standard [Formula: see text]–[Formula: see text] model, SST [Formula: see text]–[Formula: see text] model, Spalart–Allmaras model, SSG Reynolds stress model) were used to simulate the pressure difference and velocity field of the pump. In parallel, we designed a novel drive system of the axial flow blood pump, which allowed the camera to capture the internal flow field. Then we measured the flow field in the impeller region based on particle image velocimetry (PIV). Through the comparison of experiments and simulation results, the average errors of velocity field obtained by the above models are 30.97%, 19.40%, 24.25%, 15.28%, 28.51%, 23.00%, respectively. Since the SST [Formula: see text]–[Formula: see text] model has the smallest error, and the streamline is consistent with the experimental results, it is recommended to use SST [Formula: see text]–[Formula: see text] model for numerical analysis of the axial flow blood pump.

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Mechanical axial flow blood pump to support cavopulmonary circulation

The International Journal of Artificial Organs ◽

10.1177/039139880803101107 ◽

2008 ◽

Vol 31 (11) ◽

pp. 970-982 ◽

Cited By ~ 16

Author(s):

A.L. Throckmorton ◽

J. Kapadia ◽

D. Madduri

Keyword(s):

Residence Time ◽

Axial Flow ◽

Operating Conditions ◽

Blood Pump ◽

Blood Damage ◽

Fluid Forces ◽

Axial Flow Blood Pump ◽

Numerical Predictions ◽

Computational Fluid Dynamics Analysis ◽

Scalar Stress

We are developing a collapsible, percutaneously inserted, axial flow blood pump to support the cavopulmonary circulation in infants with a failing single ventricle physiology. An initial design of the impeller for this axial flow blood pump was performed using computational fluid dynamics analysis, including pressure-flow characteristics, scalar stress estimations, blood damage indices, and fluid force predictions. A plastic prototype was constructed for hydraulic performance testing, and these experimental results were compared with the numerical predictions. The numerical predictions and experimental findings of the pump performance demonstrated a pressure generation of 2–16 mm Hg for 50–750 ml/min over 5,500–7,500 RPM with deviation found at lower rotational speeds. The axial fluid forces remained below 0.1 N, and the radial fluid forces were determined to be virtually zero due to the centered impeller case. The scalar stress levels remained below 250 Pa for all operating conditions. Blood damage analysis yielded a mean residence time of the released particles, which was found to be less than 0.4 seconds for both flow rates that were examined, and a maximum residence time was determined to be less than 0.8 seconds. We are in the process of designing a cage with hydrodynamically shaped filament blades to act as a diffuser and optimizing the impeller blade shape to reduce the flow vorticity at the pump outlet. This blood pump will improve the clinical treatment of patients with failing Fontan physiology and provide a unique catheter-based therapeutic approach as a bridge to recovery or transplantation.

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NUMERICAL STUDIES OF AN AXIAL FLOW BLOOD PUMP WITH DIFFERENT DIFFUSER DESIGNS

Journal of Mechanics in Medicine and Biology ◽

10.1142/s0219519413500292 ◽

2013 ◽

Vol 13 (03) ◽

pp. 1350029 ◽

Cited By ~ 6

Author(s):

BOYANG SU ◽

LEOK POH CHUA ◽

LIANG ZHONG

Keyword(s):

Flow Field ◽

Axial Flow ◽

Pressure Head ◽

Blood Pump ◽

Flow Conditions ◽

Advantages And Disadvantages ◽

Axial Flow Blood Pump ◽

Numerical Studies ◽

Blood Pumps ◽

Computational Fluid Dynamics Cfd

Most axial flow blood pumps basically consist of a straightener, an impeller, and a diffuser. The diffuser plays a very important role in the performance of the pump to provide an adequate pressure head and to increase the hydraulic efficiency. During the development of an axial flow blood pump, irregular flow field near the diffuser hub is not desirable as it may induce thrombosis. In order to avoid this phenomenon, two approaches were adopted. In the first approach, the number of the diffuser blades was increased from three (B3, baseline model) to five (B5 model). It was observed that the flow field was improved, but the irregular flow patterns were not completely eliminated. In the second approach, we detached the blades from the diffuser hub (B3C2 model), which was integrated and rotated with the impeller hub. It was found that the rotary diffuser hub significantly improved the flow field, especially near the diffuser hub. Besides the detailed flow fields, the hydraulic and hematologic performances at various flow conditions were also estimated using computational fluid dynamics (CFD). Although each design has its own advantages and disadvantages, the B5 model was superior based on a comparative overview.

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Five Month Survival in a Calf Supported With an Intraventricular Axial Flow Blood Pump

ASAIO Journal ◽

10.1097/00002480-199507000-00025 ◽

1995 ◽

Vol 41 (3) ◽

pp. M333-M336 ◽

Cited By ~ 8

Author(s):

Steven M. Parnis ◽

Michael P. Macris ◽

Robert Jarvik ◽

John L. Robinson ◽

Jeffrey W. Kolff ◽

...

Keyword(s):

Axial Flow ◽

Blood Pump ◽

Axial Flow Blood Pump

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Induction of Ventricular Collapse by an Axial Flow Blood Pump

ASAIO Journal ◽

10.1097/00002480-199809000-00077 ◽

1998 ◽

Vol 44 (5) ◽

pp. M685-M690 ◽

Cited By ~ 21

Author(s):

Devin V. Amin ◽

James F. Antaki ◽

Philip Litwak ◽

Douglas Thomas ◽

Zhongjun J. Wu ◽

...

Keyword(s):

Axial Flow ◽

Blood Pump ◽

Axial Flow Blood Pump

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Experimental Study on Flow Field Characteristics in Seed Precipitation Tank and Influence on Physical Properties of Al(OH)3 Products

Light Metals 2020 - The Minerals, Metals & Materials Series ◽

10.1007/978-3-030-36408-3_8 ◽

2020 ◽

pp. 54-59

Author(s):

Xiangyu Zou ◽

Yan Liu ◽

Xiaolong Li ◽

Ting’an Zhang

Keyword(s):

Experimental Study ◽

Flow Field ◽

Physical Properties ◽

Flow Field Characteristics ◽

Seed Precipitation

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Improvement of Pump Performance at Off-Design Conditions

Volume 1: Aircraft Engine; Marine; Turbomachinery; Microturbines and Small Turbomachinery ◽

10.1115/85-gt-200 ◽

1985 ◽

Author(s):

J. Paulon ◽

C. Fradin ◽

J. Poulain

Keyword(s):

Experimental Study ◽

Flow Field ◽

Mass Flow ◽

Flow Characteristic ◽

Three Dimensional ◽

Operating Conditions ◽

Pump Performance ◽

Wide Range ◽

Mass Flows ◽

Design Value

Industrial pumps are generally used in a wide range of operating conditions from almost zero mass flow to mass flows larger than the design value. It has been often noted that the head-mass flow characteristic, at constant speed, presents a negative bump as the mass flow is somewhat smaller than the design mass flows. Flow and mechanical instabilities appear, which are unsafe for the facility. An experimental study has been undertaken in order to analyze and if possible to palliate these difficulties. A detailed flow analyzis has shown strong three dimensional effects and flow separations. From this better knowledge of the flow field, a particular device was designed and a strong attenuation of the negative bump was obtained.

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