Pulsatile Blood Flow in an Arterial Bifurcation

Description: This project simulates time-dependent pulsatile blood flow through a simplified arterial bifurcation using ANSYS Fluent, aiming to capture how the rhythmic nature of the cardiac cycle affects pressure and shear stress at the branching point, and to draw out clinically relevant insights into where arterial pathology is most likely to develop.

Methodology: The fluid domain is built in Design Modeler and discretized in ANSYS Meshing with an unstructured grid of 168,367 elements. Blood enters at a mass flow rate of 0.001570178 kg/s, splitting to 0.00078576 kg/s at each outlet, with an inlet pressure of 250 Pa (about 1.87515 mmHg) — well below the 80-120 mmHg typical of major human arteries, reflecting the simplified nature of the model. The pulsatile character of the flow is introduced through a User-Defined Function that varies inlet velocity sinusoidally over time to mimic the cardiac cycle, and the case is solved with a transient solver, with key results reported at t = 0.162 s, corresponding to peak systolic velocity.

Analysis: Pressure contours at t = 0.16 s show a concentration of stress at the bifurcation apex where the flow streams diverge, with local pressure reaching roughly 125 Pa — about half the inlet value — marking this location as a potential site of arterial wall rupture risk. Wall shear stress distributions further show that this same apex region experiences the lowest shear stress values in the domain, which, consistent with established medical literature linking low WSS to stenosis development, flags the bifurcation apex as particularly susceptible to atherosclerotic plaque buildup and progressive arterial narrowing.