Paper Number
BA9 

Session
Biorheology & Active Fluids

Title
Investigation of the human blood rheology in transient flows

Presentation Date and Time
February 13, 2017 (Monday) 2:45

Track / Room
Track 2 / Audubon A

Authors (Click on name to view author profile)

1. Horner, Jeffrey S. (University of Delaware, Chemical and Biomolecular Engineering)
2. Beris, Antony N. (University of Delaware, Chemical and Biomolecular Engineering)
3. Wagner, Norman J. (University of Delaware, Chemical & Biomolecular Engineering)
4. Woulfe, Donna S. (University of Delaware)

Author and Affiliation Lines (in printed abstract book)
Jeffrey S. Horner¹, Antony N. Beris¹, Norman J. Wagner¹, and Donna S. Woulfe^2
1Chemical and Biomolecular Engineering, University of Delaware, Newark, DE 19716; ²University of Delaware, Newark, DE

Speaker / Presenter 
Horner, Jeffrey S.

Text of Abstract
Blood is a complex suspension composed of erythrocytes, leukocytes, platelets, and a variety of proteins in plasma. As a result of the aggregation and subsequent breakup of erythrocytes under shear flow, blood has been shown to exhibit a non-Newtonian behavior characterized by a yield stress, shear thinning, and thixotropy. Understanding the complex nature of blood rheology is critical in detecting and understanding causes of various arterial diseases. To properly model blood flow throughout the circulatory system, not only the steady state, but also the transient behavior must be considered. Previous modeling efforts by our group have led to a parametric Casson representation for the steady state blood rheology based on literature data [1]. More recently, a structural-based model of the thixotropic behavior has been provided that semi-quantitatively describes the limited data available in the literature [2]. In this work, experimental results are presented on healthy human blood rheology with a focus on the response to transient shear experiments. By carefully preconditioning the sample, we have obtained some of the first reliable data for various transient experiments. Critical for the interpretation of these results was a full physiological characterization of the blood samples, which many previous works on blood rheology failed to provide. Based on the physiological data available, the previous model [1] predictions for the yield stress and infinite shear viscosity compared well with the steady state data. By fitting the additional model parameters to a hysteresis ramp experiment, we compare the predictions of the transient model [2] to large amplitude oscillatory shear experimental data. Our analysis shows a suitable fit at low and high shear rates. However, a breakdown from Casson behavior is detected at moderate shear rates suggesting the need to incorporate modifications to our model.

[1] Apostolidis and Beris, J. Rheol., 58, 607, (2014). [2] Apostolidis et al., J. Rheol., 59, 275, (2015).