We present detailed analysis of the accuracy of the lattice Boltzmann BGK method in simulating pulsatile flow in a 2D channel and a 3D tube. For the 2D oscillatory flow, we have observed a half time-steps shift between the theory and the simulation, that enhances the accuracy at least one order of magnitude. For 3D tube flow, we have tested the accuracy of the lattice Boltzmann BGK method in recovering the Womersley solution for pulsatile flow in a rigid tube with a sinusoidal pressure gradient. The obtained flow parameters have been compared to the analytical solutions. The influence of different boundary conditions such as the bounce-back and inlet-outlet boundary conditions on the accuracy was studied. Relative errors of the order of 0.001 in 2D with the bounce back on the nodes have been achieved. For the 3D simulations, it has been possible to reduce the error from 15% with the simple bounce-back to less than 5% with a curved boundary condition.

The complex nature of blood flow in the human arterial system is still gaining more attention, as it has become clear that cardiovascular diseases localize in regions of complex geometry and complex flow fields. In this article, we demonstrate that the lattice Boltzmann method can serve as a mesoscopic computational hemodynamic solver. We argue that it may have benefits over the traditional Navier-Stokes techniques. The accuracy of the method is tested by studying time-dependent systolic flow in a 3D straight rigid tube at typical hemodynamic Reynolds and Womersley numbers as an unsteady flow benchmark. Simulation results of steady and unsteady flow in a model of the human aortic bifurcation reconstructed from magnetic resonance angiography, are presented as a typical hemodynamic application. r

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We present an analysis of the accuracy of the lattice Boltzmann BGK (LBGK) method in simulating pulsatile blood flow in a model of the Human Abdominal Aorta. The flow is driven by a systolic pressure cycle. As a benchmark, we consider fully developed pulsatile flow in a straight tube. We compare velocity profiles and shear stress to the analytical Womersley solutions. The accuracy of the bounce-back on the links and a curved boundary condition is compared at different Mach numbers. Preliminary results of systolic flow in the human abdominal aorta are presented.

The capability of the lattice Boltzmann method as an accurate mesoscopic solver for unsteady non-Newtonian flows is shown by investigating pulsatile shear-thinning blood flow in a three-dimensional idealised vessel. The non-Newtonian behaviour of blood flow is modelled by the Carreau-Yasuda viscosity model. Higher velocity and shear stress magnitudes, relative to Newtonian cases, are observed for the shear-thinning simulations in response to changes in the shear-rate dependent Womersley parameter. We also investigate the flexibility of the method through the shear-thinning behaviour of the lattice Boltzmann relaxation parameter at different Deborah numbers.