Abdel Monim M. Artoli

Lattice BGK simulations of flow in a symmetric bifurcation

Surgical planning as a treatment for vascular diseases requires fast blood flow simulations that are efficient in handling changing geometry. It is, for example, necessary to try different paths of a planned bypass and study the resulting hemodynamic flow fields before deciding the final geometrical solution. With the aid of a real time interactive simulation environment that uses an efficient flow solver, this allows flexible treatment planning. In this article, we demonstrate that the lattice Boltzmann method can be an alternative robust computational fluid dynamics technique for such kind of applications. Steady flow in a 2D symmetric bifurcation is studied and the obtained flow fields and stress tensor components are compared to those obtained by a Navier-Stokes (NS) solver. We also demonstrate that the method is fully adaptive to interactively changing geometry.

Unsteady flow in a 2D elastic tube with the LBGK method

We report results of unsteady, harmonic flow simulations with the lattice BGK method in two-dimensional elastic tubes. The tubes are assumed to obey a simple constitutive equation, linearly relating the diameter of the tube to the pressure difference inside and outside the tube. First, as a benchmark, we present results of steady flow in such elastic tubes, and compare the performance of three different boundary conditions for the solid wall. Next, we present results of unsteady (harmonic) flow in the elastic tube, and validate the results by comparing them with theoretical expressions for the dispersion relation of the complex speed of traveling waves in the tube. Within the range of Womersley numbers tested the agreement between the simulations and the theory is good.

Accuracy of 2D Pulsatile Flow in the Lattice Boltzmann BGK Method

We present detailed analysis of the accuracy of the lattice Boltzmann BGK (LBGK) method in simulating oscillatory flow in a two dimensional channel. Flow parameters such as velocity and shear stress have been compared to the analytic solutions. Effects of different boundary conditions on the accuracy have been tested. When the flow is driven by a body force, we have observed a shift in time between the theory and the simulation, being about +0.5, which when taken into account enhances the accuracy at least one order of magnitude.

Lattice Boltzmann, a robust and accurate solver for interactive computational hemodynamics

Surgical planning as a treatment for vascular diseases requires fast blood flow simulations that are effcient in handling changing geometry. It is, for example, necessary to try different paths of a planned bypass and study the resulting hemodynamic flow fields before deciding the final geometrical solution. With the aid of a real time interactive simulation environment that uses an efficient flow solver, this allows flexible treatment planning. In this article, we demonstrate that the lattice Boltzmann method can be an alternative robust CFD technique for such kind of applications. Steady flow in a 2D symmetric bifurcation is studied and the obtained flow fields and stress tensor components are compared to those obtained by a Navier-Stokes (NS) solver. We also demonstrate that the method is fully adaptive to interactively changing geometry.