Computational Fluid Dynamics based redesign of the Magnetically Levitated Blood Shearing Device for Hemolysis Predictions
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| Title: | Computational Fluid Dynamics based redesign of the Magnetically Levitated Blood Shearing Device for Hemolysis Predictions |
|---|---|
| Authors: | Revankar, Shanoo |
| Committee Members: | Steven W. Day |
| Summary: | Annular Couette type blood shearing devices have been used for analysis of blood damage related to device induced shear stress. Two important factors in predicting cell damage are the magnitude of stress and the duration of exposure to the stress. Several previous devices for blood damage analysis consist of concentric cylinders with one cylinder rotating and the other held stationary. This generates a Couette flow between the cylinders. In a typical apparatus, the shear stress can be controlled by varying the rotation of the inner cylinder and the exposure time can be controlled by controlling the axial velocity of the fluid through the device. The higher the rotational speed the higher the magnitude shear stress. However, apparati are susceptible to a flow instability at high rotational speeds. This flow instability is characterized by toroidal vortices and may be predicted by the Taylor number, which is related to the fluid viscosity, gap and rotational speed. If the critical Taylor number is exceeded, Taylor vortices will exist. Taylor vortices are undesirable because blood cells may become entrapped in these vortices and increase exposure time thus leading to distorted hemolysis data. Because shear stress is also a function of the gap and rotational speed, the avoidance of Taylor vortices places limits the shear stress and exposure times that can be achieved in this type of a device. Changing the gap size and shape affects the formation of Taylor vortices. In this study several variations of the gap shape and size of the flow path of a blood shearing device are investigated numerically in order to find the geometry that has a physiologically relevant range of shear stress and exposure time while avoiding Taylor vortices. The proposed design will be used in future studies to study the effect of shear stress on the blood for a certain exposure time. |
| URL: | https://scholarworks.rit.edu/theses/6634 |
| Database: | OpenDissertations |
| FullText | Text: Availability: 0 |
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| Header | DbId: ddu DbLabel: OpenDissertations An: ddu.oai.scholarworks.rit.edu.theses.7639 AccessLevel: 6 PubType: Dissertation/ Thesis PubTypeId: dissertation PreciseRelevancyScore: 0 |
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| Items | – Name: Title Label: Title Group: Ti Data: Computational Fluid Dynamics based redesign of the Magnetically Levitated Blood Shearing Device for Hemolysis Predictions – Name: Author Label: Authors Group: Au Data: <searchLink fieldCode="AR" term="%22Revankar%2C+Shanoo%22">Revankar, Shanoo</searchLink> – Name: Author Label: Committee Members Group: Au Data: <searchLink fieldCode="CO" term="%22Steven+W%2E+Day%22">Steven W. Day</searchLink> – Name: Abstract Label: Summary Group: Ab Data: Annular Couette type blood shearing devices have been used for analysis of blood damage related to device induced shear stress. Two important factors in predicting cell damage are the magnitude of stress and the duration of exposure to the stress. Several previous devices for blood damage analysis consist of concentric cylinders with one cylinder rotating and the other held stationary. This generates a Couette flow between the cylinders. In a typical apparatus, the shear stress can be controlled by varying the rotation of the inner cylinder and the exposure time can be controlled by controlling the axial velocity of the fluid through the device. The higher the rotational speed the higher the magnitude shear stress. However, apparati are susceptible to a flow instability at high rotational speeds. This flow instability is characterized by toroidal vortices and may be predicted by the Taylor number, which is related to the fluid viscosity, gap and rotational speed. If the critical Taylor number is exceeded, Taylor vortices will exist. Taylor vortices are undesirable because blood cells may become entrapped in these vortices and increase exposure time thus leading to distorted hemolysis data. Because shear stress is also a function of the gap and rotational speed, the avoidance of Taylor vortices places limits the shear stress and exposure times that can be achieved in this type of a device. Changing the gap size and shape affects the formation of Taylor vortices. In this study several variations of the gap shape and size of the flow path of a blood shearing device are investigated numerically in order to find the geometry that has a physiologically relevant range of shear stress and exposure time while avoiding Taylor vortices. The proposed design will be used in future studies to study the effect of shear stress on the blood for a certain exposure time. – Name: URL Label: URL Group: URL Data: <link linkTarget="URL" linkTerm="https://scholarworks.rit.edu/theses/6634" linkWindow="_blank">https://scholarworks.rit.edu/theses/6634</link> |
| PLink | https://search.ebscohost.com/login.aspx?direct=true&site=eds-live&db=ddu&AN=ddu.oai.scholarworks.rit.edu.theses.7639 |
| RecordInfo | BibRecord: BibEntity: Languages: – Code: eng Text: English Subjects: – SubjectFull: Fluid dynamics--Mathematics Type: general – SubjectFull: Blood--Circulation Type: general – SubjectFull: Artificial Type: general – SubjectFull: Hemolysis and hemolysins Type: general Titles: – TitleFull: Computational Fluid Dynamics based redesign of the Magnetically Levitated Blood Shearing Device for Hemolysis Predictions Type: main BibRelationships: HasContributorRelationships: – PersonEntity: Name: NameFull: Revankar, Shanoo IsPartOfRelationships: – BibEntity: Dates: – D: 10 M: 01 Type: published Y: 2013 |
| ResultId | 1 |
