Paper Number
AR29 

Session
Applied Rheology and Rheology Methods

Title
Connecting structural thixotropic models with non-equilibrium thermodynamic principles for human blood

Presentation Date and Time
October 13, 2021 (Wednesday) 3:45

Track / Room
Track 2 / Ballroom 7

Authors (Click on name to view author profile)

  1. Armstrong, Matthew J. (United States Military Academy, Department of Chemistry and Life Science)
  2. Pincot, Andre (United States Military Academy)
  3. Jariwala, Soham (University of Delaware, Chemical & Biomolecular Engineering)
  4. Horner, Jeffrey (Sandia National Lab)
  5. Beris, Antony N. (University of Delaware, Chemical & Biomolecular Engineering)
  6. Wagner, Norman J. (University of Delaware, Chemical & Biomolecular Engineering)

Author and Affiliation Lines (in printed abstract book)
Matthew J. Armstrong1, Andre Pincot2, Soham Jariwala3, Jeffrey Horner4, Antony N. Beris3 and Norman J. Wagner3
1Department of Chemistry and Life Science, United States Military Academy, West Point, NY 10996; 2United States Military Academy, West Point, NY 10996-1008; 3Chemical & Biomolecular Engineering, University of Delaware, Newark, DE 19716; 4Sandia National Lab, Albuquerque, NM

Speaker / Presenter 
Armstrong, Matthew J.

Keywords
theoretical methods; computational methods; biological materials; colloids

Text of Abstract
Recent work modeling the rheological behavior of human blood indicates that blood has all of the hallmark features of a complex material, including shear-thinning, viscoelastic behavior, a yield stress and thixotropy. This complex rheological behavior emerges as a consequence of a complex microstructure to which key components are the deformable red blood cells that at the high concentrations present and facilitated by fibrinogen tend also to aggregate forming mostly linear (but connected into loose networks) rouleaux structures. A key component to most blood flow models has been the presence of one or more structural parameters to characterize the dynamics of those rouleaux structures (present at lower shear rates) while, more recently, additional viscoelastic modeling components have been proposed to address viscoelastic effects due to the individual red blood cell deformation, at higher shear rates. Following that path, successive recent improvements in the family of phenomenological structural thixotropic models have begun to asymptotically approach their respective limits with respect to accuracy for steady state and transient shear flows. Their application remains limited to unidirectional shear flows. A new family of full tensorial models has recently emerged using a thermodynamically consistent framework. Those models have as yet though to be tested against the detailed transient data employed in our earlier work. Finally, a parallel multiscale modeling effort has attempted to better connect the structural dynamics to more physical models of the rouleaux aggregation process using a population balance approach. We perform that comparison here as well as between the predictions of those models and the most recent enhanced thixotropic modified Horner-Armstrong-Wagner-Beris (mHAWB) and several versions of a new proposed Non-Equilibrium Thermodynamics modified Horner-Armstrong-Jariwala-Wagner-Beris (mHAJWB). Following the formalism of Beris & Edwards. The (NET) mHAJWB model is a fully tensorial model.