Aortic Coarctation Simulation Based on the Lattice Boltzmann Method: Benchmark Results

We investigate a patient specific blood flow simulation through a transverse aortic arch with a moderate thoracic aortic coarctation, where particular attention is paid to the blood pressure gradient through the coarctation. The challenge in this context is the complex geometry containing a stenosis, which results in complex flow patterns. The fluid is assumed to be incompressible and Newtonian. Its dynamic is usually described by an Navier-Stokes equation with appropriate boundary conditions. Instead, we modeled the problem mesoscopically by a family of BGK-Boltzmann equations those solutions reaches that of a corresponding Navier-Stokes system in a certain limit. For discretization we take advantage of lattice Boltzmann methods, which are realized within the open-source library OpenLB. A realistic transient flow profile of the cardiac output for a human at rest was used to specify the inflow boundary condition at the aortic root, whereas the outflow at the descending aorta was modeled by a pressure boundary condition. A short introduction to lattice Boltzmann methods is provided and especially the used boundary conditions are introduced in detail. The exact simulation setup is stated and the obtained results are discussed.