Characterization of anisotropic turbulence behavior in pulsatile blood flow
| Autor: | Matts Karlsson, Magnus Andersson |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 2021 |
| Předmět: |
0206 medical engineering
Strömningsmekanik och akustik 02 engineering and technology Reynolds stress Inflow 030204 cardiovascular system & hematology Barycentric coordinate system Tensor field Physics::Fluid Dynamics 03 medical and health sciences 0302 clinical medicine Barycentric anisotropy invariant map Patient-specific scale-resolved computational hemodynamics Reynolds stress and dissipation tensor MRI turbulence measurements Verification and validation Tensor Anisotropy Physics Original Paper Fluid Mechanics and Acoustics Turbulence Mechanical Engineering Mechanics 020601 biomedical engineering Modeling and Simulation Turbulence kinetic energy Biotechnology |
| Zdroj: | Biomechanics and Modeling in Mechanobiology |
| Popis: | Turbulent-like hemodynamics with prominent cycle-to-cycle flow variations have received increased attention as a potential stimulus for cardiovascular diseases. These turbulent conditions are typically evaluated in a statistical sense from single scalars extracted from ensemble-averaged tensors (such as the Reynolds stress tensor), limiting the amount of information that can be used for physical interpretations and quality assessments of numerical models. In this study, barycentric anisotropy invariant mapping was used to demonstrate an efficient and comprehensive approach to characterize turbulence-related tensor fields in patient-specific cardiovascular flows, obtained from scale-resolving large eddy simulations. These techniques were also used to analyze some common modeling compromises as well as MRI turbulence measurements through an idealized constriction. The proposed method found explicit sites of elevated turbulence anisotropy, including a broad but time-varying spectrum of characteristics over the flow deceleration phase, which was different for both the steady inflow and Reynolds-averaged Navier–Stokes modeling assumptions. Qualitatively, the MRI results showed overall expected post-stenotic turbulence characteristics, however, also with apparent regions of unrealizable or conceivably physically unrealistic conditions, including the highest turbulence intensity ranges. These findings suggest that more detailed studies of MRI-measured turbulence fields are needed, which hopefully can be assisted by more comprehensive evaluation tools such as the once described herein. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|