Reynolds Stresses and Hemolysis in Turbulent Flow Examined by Threshold Analysis

Ozturk, Mesude; O’Rear, Edgar A.; Papavassiliou, Dimitrios V.

doi:10.3390/fluids1040042

Cited by 10 publications

(7 citation statements)

References 54 publications

(94 reference statements)

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“…20–24 A common approach to consider turbulent effect on hemolysis is to formulate effective stress τeff using viscous stress together with Reynolds stress. 25–28 However, it has been shown that the Reynolds stress is an inaccurate indicator of turbulent effects on hemolysis, 29–33 and tends to overpredict the level of hemolysis. 24 Wu et al.…”

Section: Introductionmentioning

confidence: 99%

Effect of turbulent inlet conditions on the prediction of flow field and hemolysis in the FDA ideal medical device

Zhang

Gao

et al. 2019

Proceedings of the Institution of Mechanical Engineers, Part C:

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Hemolysis is one of the most important issues of blood contacting artificial organs. Computational fluid dynamics, in conjunction with hemolysis models, has been widely used to predict the flow field and hemolysis during the development phase of these devices. It is widely accepted that hemolysis is related to flow field parameters, such as stress and energy dissipation. It is known that inlet boundary conditions such as turbulent intensity have important effects on flow fields. Nonetheless, the influence of inlet turbulent intensity on hemolysis is not yet clear. This study investigates the influence of turbulent intensity on the prediction of flow field and hemolysis in the FDA benchmark nozzle model. Three configurations are investigated: first is the original nozzle model (with a gradual contraction, throat, and sudden expansion); the second is composed only of the throat and sudden expansion; the third one is similar with the second, but with a shorter throat. Four turbulent intensities are considered, ranging from 1% to 20%. For the first configuration, the influence of turbulent intensity on both flow field and hemolysis is very small and limited prior to the gradual contraction, while for the other two configurations, the influence is considerable. The jet breaks down sooner with increased turbulent intensity. Both turbulence dissipation rate and Reynolds stress increase in the throat with increased turbulent intensity, but decrease after the jet breaks down. The influence of turbulent intensity is more considerable for the configuration with a shorter inlet. The influence of turbulent intensity on the prediction of hemolysis is up to 38.5%. This study shows that turbulent intensity can have considerable influence on the prediction of flow field and hemolysis in blood-contacting devices, thus should be taken in account when conducting blood compatibility design.

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Section: Introductionmentioning

confidence: 99%

Effect of turbulent inlet conditions on the prediction of flow field and hemolysis in the FDA ideal medical device

Zhang

Gao

et al. 2019

Proceedings of the Institution of Mechanical Engineers, Part C:

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“…The power-law model established by Giersiepen et al (1990) has been considered in various studies as a fundamental model to estimate blood damage (Einav and Bluestein, 2004;Nobili et al, 2008;Wu et al, 2010;Wu et al, 2011). The limitation of this model is the requirement of empirically deriving the coefficients of the power law formulation for each prosthetic device (Ozturk et al, 2016), and their physical inconsistencies. The mathematical formula can be written as , where a, b, and c are constant values, is the acting shear stress, and is the exposure time.…”

Section: Introductionmentioning

confidence: 99%

Towards computational prediction of flow-induced damage of blood cells using a time-accumulated model

Gharaie

Mosadegh

Morsi

2017

JBSE

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Currently, there is no definite mathematical model to evaluate damage to blood cells, especially for cardiovascular devices with complex flow profiles due to turbulent flow and moving parts. This paper describes a finite volume technique that can more accurately predict damage of red blood cells and platelets by tracking their shear stress history and calculating their accumulated damage. Three standard power-law models for calculating the damage to the blood cells are compared to a novel modified model which takes into account a particle accumulated history and corrects for issues in previous models that miscount for decreasing shear stress. As an example, the damage to blood cells are determined for specific streamlines along a prosthetic polymer-based aortic valve, which is a cardiac device with low levels of damage, allowing for the sensitivity of these models to be tested. The results suggest that the new modified model provides the most accurate prediction of damage.

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“…** Increase of 20mg/dl in plasma Hb was considered as the threshold value for Kameneva, et al [122] study. *** This is the cumulative exposure time estimated by Ozturk, et al [125]…”

Section: Hemolysis Threshold In Laminar Viscous Shear Flowmentioning

confidence: 91%

“…114 The first issue with the Garon & Farinas [160] method is highlighted by the difference between Eqs. (127) and (125), which is that the difference between local velocity and the average velocity along the streamline that passes through the point is not included in Eq. (127).…”

Section: Transformation Of the Linearized Damage Functionmentioning

confidence: 99%

Improving flow-induced hemolysis prediction models.

Faghih¹

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Sharp, who has been a helpful teacher, a kind mentor and a great friend throughout my study. Without his unfailing patience and never-ending motivation and guidance, none of this work would have been possible. He has extensively contributed to my personal as well as professional growth. I would also like to thank Dr. George Pantalos, Dr. Stuart Williams and Dr. Srinivasan C. Rasipuram, for accepting to be on my dissertation committee and for providing their constructive advice during my research at the University of Louisville. Particularly, I would want to thank Dr. George Pantalos for providing me with the human blood samples for the experimental part of my research. Additionally, I want to thank Dr. Stuart Williams for providing me with some of the lab facilities I needed for my experiment, including but not limited to the 40X Extra Long Working Distance microscope objective. Furthermore, I must show my appreciation for various faculty and staff at the University of Louisville, especially John Jones, the technician at the Mechanical Engineering Department. John Jones has, indeed, helped me a lot with design, machining, fabrication and assemblage of different devices throughout my research.

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Reynolds Stresses and Hemolysis in Turbulent Flow Examined by Threshold Analysis

Cited by 10 publications

References 54 publications

Effect of turbulent inlet conditions on the prediction of flow field and hemolysis in the FDA ideal medical device

Effect of turbulent inlet conditions on the prediction of flow field and hemolysis in the FDA ideal medical device

Towards computational prediction of flow-induced damage of blood cells using a time-accumulated model

Improving flow-induced hemolysis prediction models.

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