Effects of shear rate and suspending viscosity on deformation and frequency of red blood cells tank-treading in shear flows

Abstract

The tank-treading rotation of red blood cells (RBCs) in shear flows has been studied extensively with experimental, analytical, and numerical methods. Even for this relatively simple system, complicated motion and deformation behaviors have been observed, and some of the underlying mechanisms are still not well understood. In this study, we attempt to advance our knowledge of the relationship among cell motion, deformation, and flow situations with a numerical model. Our simulation results agree well with experimental data, and confirm the experimental finding of the decrease in frequency/shear-rate ratio with shear rate and the increase of frequency with suspending viscosity. Moreover, based on the detailed information from our simulations, we are able to interpret the frequency dependency on shear rate and suspending viscosity using a simple two-fluid shear model. The information obtained in this study thus is useful for understanding experimental observations of RBCs in shear and other flow situations; the good agreement to experimental measurements also shows the potential usefulness of our model for providing reliable results for microscopic blood flows.

Keywords::

• erythrocyte
• tank-treading
• deformation index
• shear flow
• lattice Boltzmann method

Acknowledgements

JZ thanks Dr T. M. Fischer at RWTH Aachen University (Aachen, Germany) for helpful communications and providing the experimental data in Fischer (2007), and Dr H. T. Low at the National University of Singapore for sending us a copy of the Ph.D. thesis by Dr Y. Sui.

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This work was supported by the Laurentian University Research Fund (LURF) and the Laurentian Work Study program. This research has been enabled by the use of computing resources provided by WestGrid (westgrid.ca), SHARCNet (sharcnet.ca), and Compute/Calcul Canada (computecanada.org).