Blood Flow in Clogged Artery CFD Simulation

# Blood Flow in Occluded Artery - Project Overview

This study employs ANSYS Fluent software to simulate hemodynamics in a stenosed artery through CFD analysis. The model incorporates a horizontal vessel featuring a curved obstruction at its midpoint along the flow pathway. Blood is characterized by a density of 1035 kg/m³ and viscosity of 0.0043 Pa·s. 

The vessel geometry is constructed using a curved profile based on a Gaussian distribution function, which mathematically describes the radial variation along the vessel's longitudinal axis.

The function is dependent on the axial coordinate (z), with a stenosis severity (st) of 0.90 (representing 90% occlusion) and a geometric slope parameter (σ) of 0.85 defining the constriction gradient. Blood enters at a mass flow rate of 0.013662 kg/s. 

The primary research objective is to quantify the pressure differential generated along the flow path due to arterial stenosis.

# Geometric Design & Computational Grid

The three-dimensional geometry was developed in ANSYS Design Modeler. The configuration consists of a cylindrical vessel with mid-section stenosis. The constricted profile was generated by revolving a parametric curve around the vessel's centerline axis. This curve was defined by importing a coordinate dataset containing discrete spatial points.

The vessel measures 0.18 m in length with a nominal diameter of 0.004 m.

Mesh generation was performed in ANSYS Meshing utilizing a structured grid topology comprising 431,156 computational cells. The accompanying figure illustrates the mesh configuration.

# Computational Setup

The simulation incorporates the following assumptions:

- Pressure-based solution algorithm
- Steady-state flow conditions
- Gravitational effects neglected

**Summary of Simulation Parameters:**

| **Category** | **Parameter** | **Setting** |
|--------------|---------------|-------------|
| **Flow Model** | Viscous treatment | Laminar |
| **Inlet Boundary** | Type | Mass flow inlet |
| | Mass flow rate | 0.013662 kg/s |
| **Outlet Boundary** | Type | Pressure outlet |
| | Gauge pressure | 0 Pa |
| **Wall Boundary** | Motion | Stationary/no-slip |
| **Solution Method** | Coupling scheme | SIMPLE |
| | Pressure discretization | Second-order |
| | Momentum discretization | Second-order upwind |
| **Initialization** | Method | Standard |
| | Gauge pressure | 0 Pa |
| | Axial velocity | 1.054351 m/s |

# Findings

Post-processing yielded two- and three-dimensional contour visualizations of pressure, velocity, and pressure gradient distributions. Additionally, a plot depicting static pressure variation along the vessel centerline was generated using normalized axial distance coordinates.

Analysis reveals that the maximum pressure drop occurs within and immediately downstream of the stenotic region, demonstrating the hemodynamic impact of arterial occlusion.