A PROBLEM-ORIENTED APPROACH TO THE NUMERICAL MODELING OF HEMODYNAMIC PROBLEMS

A physiological problem-oriented approach to the numerical modelling o f haemodynamic problems is presented. Numerical procedures based on tw o different approaches (1) the finite volume method (FVM) and (2) the finite element method (FEM) are described. Both methods employ the ful l three-dimensional time-dependent Navier-Stokes and continuity equati ons, and can accommodate non-Newtonian fluid behaviour. In the FVM cod e, motion of the wall is allowed by using a transient gridding techniq ue, which requires either a prescribed wall movement or a given pressu re-radius relationship. In the FEM code, by contrast, the wall motion is predicted by solving the equations governing the motion of a linear ly elastic, incompressible, isotropic solid undergoing small deformati ons. Basic testing cases are presented, with comparable theoretical so lutions. The physiological validity of the predictions is assessed thr ough comparisons with high precision in vivo ultrasound data for flow in (a) a porcine carotid artery, and (b) a canine peripheral artery bi furcation. Effects of various factors on the flow field and shear stre ss distributions are investigated. Physiological phenomena which shoul d be taken into account in numerical modelling are also discussed. (C) 1997 Elsevier Science Ltd.