Paper Number
BB39 

Session
Biomaterials and Biological Systems

Title
Modeling of human blood rheology in transient shear flows

Presentation Date and Time
October 8, 2014 (Wednesday) 2:45

Track / Room
Track 2 / Commonwealth B

Authors (Click on name to view author profile)

1. Apostolidis, Alex J. (University of Delaware, Chemical and Biomolecular Engineering)
2. Armstrong, Matthew J. (University of Delaware, Chemical and Biomolecular Engineering)
3. Beris, Antony N. (University of Delaware, Chemical and Biomolecular Engineering)

Author and Affiliation Lines (in printed abstract book)
Alex J. Apostolidis, Matthew J. Armstrong, and Antony N. Beris
Chemical and Biomolecular Engineering, University of Delaware, Newark, DE 19716

Speaker / Presenter 
Apostolidis, Alex J.

Text of Abstract
This investigation is a continuation of our efforts to model blood flow rheology from steady-state [1] to time-dependent. The basis is a structural parameter thixotropic model. A modified version of the “Delaware model” [2] is used so that, at steady state, it reduces to the Casson constitutive model for low and moderate shear rates, consistent to [1]. Interestingly, at higher shear rates the model asymptotes to a Newtonian behavior, consistent to some earlier, previously unexplained, data by Merrill and Pelletier [3]. Exploiting the parameterization developed for the steady state Casson model [1], the transient thixotropic model introduces only four additional parameters, all with a specific physical meaning: two maximum strain values, representing the behavior at zero and at infinite shear rates, respectively, and two kinematic parameters, governing the relaxation of the structural parameter and the elastic modulus. The model is validated against a number of time-dependent shear flow data due to: a) a rectangular step increase [4], b) a triangular step change (hysteresis curves) [5], and c) LAOS [6]. This extensive comparison shows the capability of our model to capture well at least the low and modest shear rates behavior.
References
[1] Apostolidis, A. J., and A. N. Beris, J. Rheol. 58, 607-633 (2014).
[2] Mujumdar, A., A. N. Beris, and A. B. Metzner, J. Non-Newtonian Fluid Mech. 102, 157-178 (2002).
[3] Merrill, E. W., and G. A. Pelletier, J. of Applied Physiology 23, 178-& (1967).
[4] Bureau, M., J. C. Healy, D. Bourgoin, and M. Joly, Biorheology 17, 191-203 (1980).
[5] Bureau, M., J. C. Healy, D. Bourgoin, and M. Joly, Rheol. Acta 18, 756-768 (1979).
[6] Sousa, P. C., J. Carneiro, R. Vaz, A. Cerejo, F. T. Pinho, M. A. Alves, and M. S. N. Oliveira, Biorheology 50, 269-282 (2013).