Meeting Abstract

82.1  Sunday, Jan. 6  Vortex formation in the embryonic heart MILLER, L. A.; University of North Carolina, Chapel Hill lam9@email.unc.edu

The vertebrate heart first forms as a simple tube that pumps blood at low Reynolds numbers (10^-2 – 10^-1) without the use of valves. As the heart develops, the atrium and ventricle bulge out from the heart tube, and valves begin to form through the expansion of the endocardial cushions. During this stage of development, the Reynolds number increases, and vortices form in each of the chambers. This transition to vortical flow is significant because fluid forces acting on the heart are necessary for correct chamber and valve morphogenesis. Computational fluid dynamics and flow visualization with physical models were used to explore how this transition depends upon the geometry of the heart, the Reynolds number, and the kinetics of contraction. The immersed boundary method was used to simulate the fluid-structure interaction between the contracting heart tube wall and the blood. Flow visualization using rigid, simplified models of the heart were used to validate the numerical results. While the majority of the work is based upon the assumption that the blood is Newtonian, preliminary results from simulations modeling blood as a shear-thinning viscoelastic fluid will also be presented.