Team for Advanced Flow Simulation and Modeling

For more information:
  tezduyar@gmail.com

Computer Modeling of a Cerebral Aneurysm

The computer model is a close approximation to the computed tomography (CT) model of a segment of the middle cerebral artery of a 57 year-old male with cerebral aneurysm.

One of the major computational challenges in cardiovascular fluid mechanics is accurate modeling of the fluid-structure interactions between the blood flow and arterial walls. The blood flow depends on the arterial geometry, and the deformation of the arterial wall depends on the blood flow. The mathematical equations governing the blood flow and arterial deformations need to be solved simultaneously, with proper kinematic and dynamic conditions coupling the two physical systems.

The numerical methods used in this computation were introduced and implemented on parallel computing platforms by the Team for Advanced Flow Simulation and Modeling (T*AFSM). The powerful set of numerical methods introduced by the T*AFSM over the years and used in this computation includes the quasi-direct fluid-structure interaction method [1, 2] developed recently at Rice University. The CT model of the artery approximated in this computation was reported in [3]. The blood flow rate used in the computation during the systolic cycle is a close approximation to the one reported in [4]. The computation was carried out on the ADA system at Rice University.

Fig 1. Blood-flow patterns at an instant during the systolic cycle.

Fig 2. Arterial shape at three different instants during the systolic cycle.

References:

1. T.E. Tezduyar, S. Sathe, R. Keedy and K. Stein, "Space-Time Techniques for Finite Element Computation of Flows with Moving Boundaries and Interfaces", Proceedings of the III International Congress on Numerical Methods in Engineering and Applied Sciences, Monterrey, Mexico, CD-ROM (2004).

2. T.E. Tezduyar, S. Sathe, R. Keedy and K. Stein, "Space-Time Finite Element Techniques for Computation of Fluid-Structure Interactions", Computer Methods in Applied Mechanics and Engineering, 195 (2006) 2002-2027.

3. R. Torii, M. Oshima, T. Kobayashi, K. Takagi and T.E. Tezduyar, "Influence of Wall Elasticity in Patient-Specific Hemodynamic Simulations", Computers & Fluids, published online, December 2005.

4. R. Torii, M. Oshima, T. Kobayashi, K. Takagi and T.E. Tezduyar, "Computer Modeling of Cardiovascular Fluid--Structure Interactions with the Deforming-Spatial-Domain/Stabilized Space-Time Formulation", Computer Methods in Applied Mechanics and Engineering, 195 (2006) 1885-1895.