Scaling of shear-induced diffusion and clustering in a blood-like suspension

¹ Computational Science Lab, University of Amsterdam - Science Park 904, 1098 XH, Amsterdam, The Netherlands
² Electric Ant Lab B.V. - Panamalaan 4K, 1019AZ, Amsterdam, The Netherlands
³ ITMO University - Saint-Petersburg, Russian Federation

Received: 24 September 2015
Accepted: 20 April 2016

Abstract

The transport of cells and substances in dense suspensions like blood heavily depends on the microstructure and the dynamics arising from their interactions with red blood cells (RBCs). Computer simulations are used to probe into the detailed transport-related characteristics of a blood-like suspension, for a wide range of volume fractions and shear rates. The shear-induced diffusion of RBCs does not follow the established linear scaling with shear rate for higher volume fractions. The properties directly related to RBC deformability —stretching and flow orientation— are not sufficient to explain this departure according to the model of Breedveld, pointing to the dominance of collective effects in the suspension. A cluster size analysis confirms that collective effects dominate high volume fractions, as the mean cluster size is above 2 and the number of “free RBCs” is significantly decreased in denser suspensions. The mean duration of RBC contacts in clusters is increased in the high volume fraction and shear rate cases, showing that these clusters live longer.