A Numerical and Experimental Investigation of Transitional Pulsatile Flow in a Stenosed Channel
| Autor: | Ken Kiger, Nikolaos Beratlis, Elias Balaras, B. Parvinian |
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| Rok vydání: | 2005 |
| Předmět: |
Physics
Jet (fluid) Turbulence Flow (psychology) Models Cardiovascular Biomedical Engineering Pulsatile flow Arterial Occlusive Diseases Blood Pressure Arteries Constriction Pathologic Inflow Mechanics Laser Doppler velocimetry Vortex Physics::Fluid Dynamics Pulsatile Flow Physiology (medical) Mass flow rate Animals Humans Computer Simulation Geotechnical engineering Blood Flow Velocity |
| Zdroj: | Journal of Biomechanical Engineering. 127:1147-1157 |
| ISSN: | 1528-8951 0148-0731 |
| Popis: | In the present paper, a closely coupled numerical and experimental investigation of pulsatile flow in a prototypical stenotic site is presented. Detailed laser Doppler velocimetry measurements upstream of the stenosis are used to guide the specification of velocity boundary conditions at the inflow plane in a series of direct numerical simulations (DNSs). Comparisons of the velocity statistics between the experiments and DNS in the post-stenotic area demonstrate the great importance of accurate inflow conditions, and the sensitivity of the post-stenotic flow to the disturbance environment upstream. In general, the results highlight a borderline turbulent flow that sequentially undergoes transition to turbulence and relaminarization. Before the peak mass flow rate, the strong confined jet that forms just downstream of the stenosis becomes unstable, forcing a role-up and subsequent breakdown of the shear layer. In addition, the large-scale structures originating from the shear layer are observed to perturb the near wall flow, creating packets of near wall hairpin vortices. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
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