Pulsatile pressure and flow in arterial stenoses simulated in a mathematical model

Area of Science:

• Biomedical Engineering
• Computational Fluid Dynamics
• Cardiovascular Flow Dynamics

Background:

• Arterial stenosis significantly impacts blood flow dynamics.
• Understanding pulsatile flow patterns is critical for diagnosing and treating cardiovascular diseases.
• Mathematical modeling provides insights into complex hemodynamic changes caused by stenosis.

Purpose of the Study:

• To computationally simulate and analyze pulsatile pressure and flow velocity patterns within an axis-symmetric stenosis model.
• To investigate the formation and behavior of vortices and pressure variations in a 75% constricted artery.
• To provide detailed hemodynamic data at various time instances during a cardiac cycle.

Main Methods:

• Solving Navier-Stokes equations using the finite element method for accurate fluid dynamics simulation.
• Utilizing a pulsatile velocity profile from a straight tube as a boundary condition for stenosis calculations.
• Generating velocity vectors, streamlines, and isobars at 16 time intervals (15 degrees apart) throughout a cardiac cycle.

Main Results:

• A vortex forms distally to the stenosis as peak systolic velocity decreases.
• A local pressure minimum is observed at the vortex site due to pressure-kinetic energy conversion.
• Flow reversal initiates along the wall, shifting the vortex centrally, and a proximal vortex develops with increasing reverse flow.

Conclusions:

• The study elucidates the complex hemodynamic phenomena, including vortex dynamics and pressure fluctuations, occurring within arterial stenosis.
• Computational simulations offer valuable data for understanding the physiological consequences of significant arterial constriction.
• These findings contribute to the knowledge base for developing improved diagnostic and therapeutic strategies for stenosis-related cardiovascular conditions.