Effect of Reynolds Number on Performance of a Small Centrifugal Pump

2003 ◽  
Author(s):  
Steven W. Day ◽  
Phillip P. Lemire ◽  
Ronald D. Flack ◽  
James C. McDaniel
Keyword(s):  
Reynolds Number ◽  
Numerical Study ◽  
Internal Flow ◽  
Blood Pump ◽  
Viscous Effects ◽  
Flow Curves ◽  
Centrifugal Blood Pump ◽  
Pump Performance ◽  
Lower Reynolds Number ◽  
Reynolds Number Flows

A study of a small centrifugal blood pump has been made to address the effectiveness of traditional pump affinity laws and the influence that viscous effects, as characterized by the Reynolds number, have on the pump performance. This was investigated both experimentally and numerically on models of a small implantable centrifugal blood pump, which has an impeller diameter of 46 mm with a log spiral volute. In the experiments, the Head-Flow curves were determined for speeds between 500 and 3000 rpm and for two different viscosity fluids. It was found that lower Reynolds number flows did not adhere to conventional pump affinity laws, whereas higher Reynolds number flows scale very effectively according to pump affinity laws. The numerical study consisted of comparing the generated head and internal flow field of the pump scaled based on traditional affinity laws with and without consideration of the Reynolds number. Like the experimental results, the numerical simulations indicate that consideration of the Reynolds number is necessary to insure accurate scaling in this small pump.

An experimental performance comparison of Newtonian and non-Newtonian fluids on a centrifugal blood pump

2022 ◽  
pp. 095441192110576
Author(s):  
Ahmet Onder ◽  
Rafet Yapici ◽  
Omer Incebay
Keyword(s):  
Flow Rate ◽  
Rotational Speed ◽  
Performance Test ◽  
Newtonian Fluids ◽  
Friction Reduction ◽  
Blood Pump ◽  
Actual Performance ◽  
Centrifugal Blood Pump ◽  
Working Fluids ◽  
Pump Performance

The use of substitute fluid with similar rheological properties instead of blood is important due to ethical concerns and high blood volume consumption in pump performance test before clinical applications. The performance of a centrifugal blood pump with hydrodynamic journal bearing is experimentally tested using Newtonian 40% aqueous glycerin solution (GS) and non-Newtonian aqueous xanthan gum solution of 600 ppm (XGS) as working fluids. Experiments are performed at four different rotational speeds which are 2700, 3000, 3300, and 3600 rpm; experiments using GS reach between 8.5% and 37.2% higher head curve than experiments using the XGS for every rotational speed. It was observed that as the rotational speed and flow rate increase, the head curve difference between GS and XGS decreases. This result can be attributed to the friction reduction effect when using XGS in experiments at high rotation speed and high flow rate. Moreover, due to different fluid viscosities, differences in hydraulic efficiency were observed for both fluids. This study reveals that the use of Newtonian fluids as working fluids is not sufficient to determine the actual performance of a blood pump, and the performance effects of non-Newtonian fluids are remarkably important in pump performance optimizations.

Numerical study of the effect of flow path geometry on the property of a monopivot centrifugal blood pump

2017 ◽  
Vol 2017.29 (0) ◽  
pp. 1B12
Author(s):  
Daiki GOTO ◽  
Toru HYAKUTAKE ◽  
Masahiro NISHIDA ◽  
Daisuke SAKOTA ◽  
Ryo KOSAKA ◽  
...  
Keyword(s):  
Numerical Study ◽  
Flow Path ◽  
Blood Pump ◽  
Centrifugal Blood Pump ◽  
Path Geometry

Modified Fabrication Techniques Lead to Improved Centrifugal Blood Pump Performance

ASAIO Journal ◽  
1994 ◽  
Vol 40 (3) ◽  
pp. M767-M772 ◽  
Author(s):  
John J. Pacella ◽  
Andrew H. Goldstein ◽  
George J. Magovern ◽  
Richard E. Clark
Keyword(s):  
Blood Pump ◽  
Centrifugal Blood Pump ◽  
Pump Performance

Miniature gas turbines: Numerical study of the effects of heat transfer and Reynolds number on the performance of an axial compressor

2014 ◽  
Vol 03 (02) ◽  
pp. 1450008 ◽  
Author(s):  
Junting Xiang ◽  
Jörg Uwe Schlüter ◽  
Fei Duan
Keyword(s):  
Heat Transfer ◽  
Reynolds Number ◽  
Gas Turbines ◽  
Numerical Study ◽  
Axial Compressor ◽  
Thermal Conditions ◽  
Wall Heat Transfer ◽  
Viscous Effects ◽  
Computational Fluid Dynamics Cfd ◽  
Compressor Performance

In the present work, we focus on computational investigations of the Reynolds number effect and the wall heat transfer on the performance of axial compressor during its miniaturization. The NASA stage 35 compressor is selected as the configuration in this study and computational fluid dynamics (CFD) is used to carry out the miniaturization process and simulations. We perform parameter studies on the effect of Reynolds number and wall thermal conditions. Our results indicate a decrease of efficiency, if the compressor is miniaturized based on its original geometry due to the increase of viscous effects. The increased heat transfer through wall has only a small effect and will actually benefit compressor performance based on our study.

Numerical Analysis of Sub-Millimeter-Scale Microturbomachinery Aerothermodynamics

2008 ◽  
Author(s):  
Philippe B. Martel ◽  
Luc G. Fre´chette
Keyword(s):  
Reynolds Number ◽  
Large Scale ◽  
Microelectromechanical Systems ◽  
Numerical Study ◽  
Reynolds Numbers ◽  
Viscous Effects ◽  
Analysis And Design ◽  
Moderate Reynolds Number ◽  
Throat Width ◽  
Solid Foundation

This paper presents a complete numerical study of the aerothermodynamics of subsonic moderate Reynolds number microturbomachinery using 2D computational fluid dynamics (CFD) on 24 cascade geometries and covering over 2000 conditions. Profile and mixing losses, as well as deviation and heat transfer correlations are developed for use in mean-line analysis and design. Both losses and thermal transfer tend to increase with decreasing Reynolds number, Mach number, and throat width. Deviation follows large scale turbomachinery behavior but tends to increase with viscous effects. A slender cascade geometry using a modified profile is suggested, potentially increasing isentropic efficiency by as much as 15%. This work defines a solid foundation for the design of microturbines used in power microelectromechanical systems (MEMS), such as gas and steam microturbines with sub-millimeter-scale blade chords operating at moderate Reynolds numbers (100 < Rec < 2000).

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