Document Detail


Prediction of leakage flow in a shrouded centrifugal blood pump.
MedLine Citation:
PMID:  20883397     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
This article proposes a phenomenological model to predict the leakage flow in the clearance gap of shrouded centrifugal blood pumps. A good washout in the gap clearance between the rotating impeller surfaces and volute casing is essential to avoid thrombosis. However, excessive leakage flow will result in higher fluid shear stress that may lead to hemolysis. Computational fluid dynamics (CFD) analysis was performed to investigate the leakage flow in a miniaturized shrouded centrifugal blood pump operating at a speed of 2000 rpm. Based on an analytical model derived earlier, a phenomenological model is proposed to predict the leakage flow. The leakage flow rate is found to be proportional to h(α) , where h is the gap size and the exponent α ranges from 2.955 to 3.15 for corresponding gap sizes of 0.2-0.5 mm. In addition, it is observed that α is a linear function of the gap size h. The exponent α compensates for the variation of pressure difference along the circumferential direction as well as inertia effects that are dominant for larger gap clearances. The proposed model displays good agreement with computational results. The CFD analysis also showed that for larger gap sizes, the total leakage flow rate is of the same order of magnitude as the operating flow rate, thus suggesting low volumetric efficiency.
Authors:
Ji-Bin Teo; Weng-Kong Chan; Yew-Wah Wong
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Publication Detail:
Type:  Journal Article    
Journal Detail:
Title:  Artificial organs     Volume:  34     ISSN:  1525-1594     ISO Abbreviation:  Artif Organs     Publication Date:  2010 Sep 
Date Detail:
Created Date:  2010-10-01     Completed Date:  2011-01-13     Revised Date:  -    
Medline Journal Info:
Nlm Unique ID:  7802778     Medline TA:  Artif Organs     Country:  United States    
Other Details:
Languages:  eng     Pagination:  788-91     Citation Subset:  IM    
Copyright Information:
© 2010, Copyright the Authors. Artificial Organs © 2010, International Center for Artificial Organs and Transplantation and Wiley Periodicals, Inc.
Affiliation:
School of Mechanical and Aerospace Engineering, Nanyang Technological University, Singapore.
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MeSH Terms
Descriptor/Qualifier:
Computer Simulation
Heart-Assist Devices / adverse effects*
Hemolysis
Models, Cardiovascular*
Pressure
Prosthesis Design
Stress, Mechanical
Thrombosis / blood,  etiology
Time Factors

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine


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