Paper Number
BB1
Session
Biomaterials and Biofluid Dynamics
Title
Modeling and simulation of blood flow syneresis and pulsatile pipe flow effects
Presentation Date and Time
October 21, 2019 (Monday) 9:50
Track / Room
Track 6 / Room 306B
Authors
- van de Vyver, Tim (University of Delaware, Chemical and Biomolecular Engineering)
- Horner, Jeffrey S. (University of Delaware, Chemical and Biomolecular Engineering)
- Wagner, Norman J. (University of Delaware, Chemical and Biomolecular Engineering)
- Beris, Antony N. (University of Delaware, Chemical and Biomolecular Engineering)
Author and Affiliation Lines
Tim van de Vyver, Jeffrey S. Horner, Norman J. Wagner, and Antony N. Beris
Chemical and Biomolecular Engineering, University of Delaware, Newark, DE 19716
Speaker / Presenter
Beris, Antony N.
Text of Abstract
Blood flow simulations are used for various applications ranging from drug delivery to bypass surgery. However, due to the inherent complexity of the system, modern methods for simulating blood flow are typically oversimplified. This is particularly notable regarding the rheology of blood. Rheologically, blood is a complex fluid that exhibits pseudoplasticity, viscoelasticity, and thixotropy. Coupled with these effects is the potential for blood to separate into a pure plasma region near the walls and a concentrated red blood cell region near the center when subjected to flow, a phenomenon referred to as syneresis. Here, we present a new model that can be used to predict these inhomogeneous effects. In the model, the plasma layer thickness is connected to a structure kinetics model for the transient rheology of the blood, which enables insight into how the transient microstructure within the blood gives rise to this complex syneresis effect. Integrating the model into CFD flow simulations, we develop a robust and accurate numerical method for studying the flow of blood in arterial, pulsatile flow. The model simulation can help to understand the underlying physics and to make realistic predictions for other flow parameters under microfluidic conditions. An efficient code based on spectral collocation method has been designed to take advantage of the mathematical form of the flow conditions and the cylindrical geometry. Orthogonal Fourier and Chebyshev polynomials represent the time and axial dependence of the solution. This allows for machine-accurate solutions to be obtained for smooth problems. The numerical method was successfully validated for the calculation of Newtonian fluids, elastic solid, viscoelastic Maxwellian fluids, and power law fluids, where analytical results were available. It has then been used in conjunction with the thixotropic structure kinetics model. In doing so, we provide an accurate, robust, and computationally inexpensive technique to simulate transient and inhomogeneous blood flow.