The NavierStokes equations were solved using an open source code FreeFem++ Implicit method is used along with P2/P1 TaylorHood spatial discretization. Geometry modeling ProE, discretization Catia, data visualization Mayavi2 This work made use of the facilities of HECToR, the UK's national highperformance computing service Project report: Domain decomposition for problems of hemodynamics
Hosted by: Dr Peter Hoskins Special thanks to: Prof. Ian Marshall 

healthy carotidh=2 mm 
stenosis 30pch=2 mm 
stenosis 64pch=2 mm 
Pulsatile blood flow : reproducing the MRI data 3  20 mL/sInflow range: 3  20 mL/s (initial 4 mL/s flow) 

h=0.08 mm, dt=0.01 sec
Isosurface 
h=0.08 mm, dt=0.01 sec
Isosurface 
h=0.08 mm, dt=0.01 sec
Isosurface Vectors frontal plane 
Steady blood flow 10.5 mL/s benchmarkWe compute an initial velocity  pressure guess by the Stokes equations,This is a good strategy for low Reynolds number flow. However, for Re = 450, the nonlinear, convective term should not be neglected. The following simulations illustrate the influence of the convective term. t = 0  1 sec: steady NavierStokes flow 

h=1 mm, dt=0.005 sec 
h=1 mm, dt=0.0025 sec 
h=0.8 mm, dt=0.002 sec
MRI style

Pulsatile blood flow : sinusoidal benchmarkInflow range: 7  14 mL/s (initial 10.5 mL/s flow)t = 0  1 sec: steady NavierStokes flow t = 1  7 sec: pulsatile NavierStokes flow t = 7  8 sec: steady NavierStokes flow 

h=1 mm, dt=0.002 sec
Isosurface [116MB] 
h=1 mm, dt=0.002 sec
Isosurface [116MB] Isosurface [avi 6MB vlc player] 

cad models
You are allowed to use these models for free. 

Healthy carotid model data, h=1 mm
===========================MESH===DATA============================== Nv, Ntet, Ndof: 13201 65984 303142 Area1: 65.6909 Area2: 38.5022 Area3: 26.3877 Diam1: 9.14551 Diam2: 7.00161 Diam3: 5.79636 ===========================MESH===DATA============================== ===========================Global Matrix Method===================== Pressure: [min,max] 0.00036 0.07805 ux: [min,max] 5.89720 320.45148 uy: [min,max] 231.77369 180.92578 uz: [min,max] 82.96522 108.74870 u1_mean: 159.89826 Q1[mL/s]: 10.50386 u2_mean: 176.27867 Q2: 6.78711 u3_mean: 140.85175 Q3: 3.71675 Re1: 442.883 Re2: 373.797 Re3: 247.261 Solver (single time step): 99.491 [sec] Total wall time: 30412.091 [sec] ===========================Global Matrix Method===================== 

References
Ian Marshall, Computational simulations and experimental studies of 3D phasecontrast imaging of fluid flow in carotid bifurcation geometries, 2010, 

Acknowledgments
The work was carried out under the HPCEUROPA2 project (project number: 228398) with the support of the European Commission  Capacities Area  Research Infrastructures. This work made use of the facilities of HECToR, the UK's national highperformance computing service, which is provided by UoE HPCx Ltd at the University of Edinburgh, Cray Inc and NAG Ltd, and funded by the Office of Science and Technology through EPSRC's High End Computing Programme. 