Simulation and visualization of transient 3D-flow in arteries with an artificial heart valve using Lattice-Boltzmann methods

The development of flow instabilities due to high Reynolds number flow in artificial heart valve geometries inducing high strain rates and stresses often lead to hemolysis and related highly undesired effects. Geometric and functional optimization of artificial heart valves is therefore mandatory. In addition to experimental work in this field it is meanwhile possible to obtain increasing insight into flow dynamics by computer simulation of refined model problems. We report the results of the simulation of three dimensional fully transient physiological flows in a geometry similar to a CarboMedics bileaflet heart valve. The visualization of emerging complicated flow patterns gives detailed information about the transient history of the systems dynamical stability. Stress analysis indicates temporal shear stress peaks even far away from walls. The mathematical method is based on the Lattice-Boltzmann method, the code is implemented on a Workstation-Cluster and a small dedicated parallel computer in order to decrease computation time. Finally we discuss problems and shortcomings of our approach.