Mehran Tadjfar | PubMed Health

PubMed2004

Branch angle and flow into a symmetric bifurcation.

Arterial branches are found to be a major site for formation of arterial plaque. In this study, we investigate the role of the bifurcation angle on the flow into a symmetric bifurcation. Specially, how the changes in the bifurcation angle influences the distribution of axial wall shear in the bifurcation model. The flow in a range of branch opening half-angle of pi/25< or =theta< or =pi/4 are numerically simulated. The flow in the above models is calculated for the inlet flow Reynolds numbers of 250, 500, 1000, and 2000. It is found that at higher values of the opening angle of the bifurcation, the possibility and severity of flow separation at the appropriate wall location increases.

Animals↗

PubMed2002

Time-accurate, parallel, multi-zone, multi-block solver to study the human cardio-vascular system.

A parallel, time-accurate flow solver is devised to study the human cardio-vascular system. The solver is capable of dealing with moving boundaries and moving grids. It is designed to handle complex, three-dimensional vascular systems. The computational domain is divided into multiple block subdomains. At each cross section the plane is divided into twelve sub-zones to allow flexibility for handling complex geometries and, if needed, appropriate parallel data partitioning. The unsteady, three-dimensional, incompressible Navier-Stokes equations are solved numerically. A second-order in time and third-order upwind finite volume method for solving time-accurate incompressible flows based on pseudo-compressibility and dual time-stepping technique is used. For parallel execution, the flow domain is partitioned. Communication between the subdomains of the flow on Riken's VPP/700E supercomputer is implemented using MPI message-passing library. A series of numerical simulations of biologically relevant flows is used to validate this code.

Biomechanical Phenomena↗