Shear rate behaviour within in vitro thrombotic geometries: Height and surface curvature dependence

Abstract

The flow of blood past thrombi, situated within an in vitro geometry, is computed via the solution fo the three-dimensional (3D) Navier-Stokes equations. The thrombotic geometry is derived from microscopy measurements of thrombotic geometries within in vitro experiments which the in silico experiment reflects. The flow within the numerical domain is solved using the OpenFOAM package to provide an solution of the steady state and incompressible Navier-Stokes equations. Previous work (Butler et al, 2012) explored the shear rate variations that occur in a simplified thrombotic geometry. Here additional flow complexity is introduced through the complexity of the thrombus geometry. Localised fluctuations of the thrombus surface are shown to generate significant variations in the shear-rate the thrombus surface experiences. Convex and exposed surfaces are shown to have the highest shear rates. In addition to the concavity the height above the microchannel floor is shown to correlate strongly with increased shear rate.