Meeting Abstract

24.1  Monday, Jan. 5  Fluid Flow in Physical Models of the Endothelial Surface Layer GUNDERSON, J.A.*; SANTHANAKRISHNAN, A; MILLER, L.A.; Univ. of North Carolina, Chapel Hill jengun@email.unc.edu

The purpose of this study is to investigate fluid flow in physical models of the endothelial surface layer by comparing both Newtonian and non-Newtonian fluids. Newtonian fluids are characterized by a linear relationship between applied shear stress and resultant strain. Newtonian fluids are conventionally used to study biological fluid flows, but this constitutes an approximation as blood is non-Newtonian. The endothelial surface layer covers the luminal side of the endothelial cells and protrudes into the blood flow. This layer consists of the glycocalyx (proteoglycans, glycoproteins and glycolipids) and attached plasma proteins. Changes in the shear stress imposed by the blood flow are sensed by the cell and these have been proposed to be important to trigger biochemical cascades within the cell. To understand the effect of varying morphology of the endothelial surface layer on the flow field, dynamically scaled physical models were used in this study. These models consist of rows of rigid two-dimensional cylinders with varying height, cylinder array length and number density. Quantitative measurements of the differences in Newtonian and non-Newtonian flow over a range of Reynolds numbers are obtained using particle image velocimetry (PIV). Based on comparisons of these fluid properties and the experimental data, we are able to obtain a better understanding of how non-Newtonian properties might alter flow patterns and the resulting shear stress and pressure gradients.