Kinematic and Dynamic Characteristics of Pulsatile Flows in Stenotic Vessels

Nonlinear pulsatile blood flows in distensible vessels were calculated using an implicit finite-difference scheme. The time-dependent wavy lumen was mapped to a fixed rectangular domain. The transient geometric, kinematic, and dynamic boundary conditions were grouped as dimensionless parameters in the Navier-Stokes equations. The flow was controlled by a time-dependent von Karman number and the dilatation and contraction of the wall. Local acceleration components along the wall, the inlet, and the outlet were employed in the determination of the Neumann boundary condition for the pressure field. The momentum flux associated with wall motion had a significant effect on the flow rate and the resistance coefficient. The interaction of the main flow and flow separation was dominated by flow acceleration and deceleration.