Numerical analysis of blood flow through an elliptic stenosis using large eddy simulation

Area of Science:

• Cardiovascular fluid dynamics
• Biomedical engineering
• Computational fluid dynamics

Background:

• Arterial stenosis, a narrowing of the lumen, significantly alters blood flow parameters.
• Laminar flow can transition to turbulent flow due to geometric perturbations caused by stenosis.

Purpose of the Study:

• To numerically simulate blood flow through an eccentrically located, asymmetric stenosis with an elliptical cross-section.
• To analyze flow characteristics under both steady and pulsatile inflow conditions, mimicking physiological states.

Main Methods:

• Utilized computational fluid dynamics (CFD) with Large Eddy Simulation (LES) and a dynamic Smagorinsky sub-grid scale model.
• Applied the Carreau viscosity model to account for the non-Newtonian properties of blood.
• Derived pulsatile inflow waveforms from literature data for realistic physiological simulation.

Main Results:

• Simulations demonstrated a transition to turbulence in the post-stenotic region for all tested conditions (steady and pulsatile).
• Detailed analysis of mean and turbulent flow fields was performed, highlighting the impact of stenosis severity and inflow dynamics.
• The study captured the complex flow evolution, including potential relaminarization, influenced by stenosis geometry.

Conclusions:

• Eccentric, asymmetric stenosis with elliptical cross-sections induces turbulence in arterial blood flow.
• Both steady and pulsatile flow conditions lead to post-stenotic turbulence, with distinct characteristics.
• CFD simulations provide valuable insights into the hemodynamics of stenotic arteries, crucial for understanding associated pathologies.