High-fidelity large eddy simulation of blood flow through a mechanical heart valve

Bileaflet heart valves are currently the most commonly implanted type of mechanical heart valve (MHV). However, the current designs are far from being optimal and, due to non-physiological flow characteristics, significant complications often arise after implantation. We carry out a high-fidelity large eddy simulation (LES) of blood flow through a bileaflet MHV for a better understanding of the dynamics of flow in both 2-D and 3-D models. For this purpose, we employ a sixth-order Pad\'{e} approximant compact scheme that is coupled with an eleventh-order filtering procedure for removing high wave number noise. To our knowledge, this is one of the most complicated applications of high-order CFD methods, from the standpoint of geometry, and the first attempt at simulating blood flow in 3-D mechanical heart valves using such methods, with and without the overset grid methodology. The results clearly show the need for a full 3-D model for MHV. The formation of vortices and shear layers is discussed, as are their physiological implications.