MCE 482 Project - Modelling Blood Flow in Renal Artery Stenosis using COMSOL

Introduction

This tutorial guides you through modeling blood flow in renal artery stenosis using COMSOL Multiphysics. Understanding blood flow dynamics is crucial in medical applications, particularly in evaluating conditions like renal artery stenosis, which can lead to hypertension and kidney damage. By following these steps, you will learn how to set up your model, define parameters, and analyze results effectively.

Step 1: Setting Up the Model

• Open COMSOL Multiphysics: Launch the application and create a new model.
• Select the Physics: Choose the fluid flow physics interface. For this case, you will typically use the “Laminar Flow” module.
• Define Geometry:
  • Create a 2D or 3D representation of the renal artery.
  • Use the geometry tools to draw the artery, including the stenosis section where the narrowing occurs.

Step 2: Defining Material Properties

• Select Materials:
  • In the “Materials” section, add blood as a fluid material.
  • Set the properties of blood, such as density and viscosity. Typical values include:
    • Density: 1060 kg/m³
    • Viscosity: 0.0035 Pa·s
• Apply Material to Geometry: Assign the blood material to the artery geometry you defined.

Step 3: Setting Boundary Conditions

• Inlet and Outlet Conditions:
  • Define the inlet boundary where blood enters the artery. Set a velocity or pressure condition.
  • For the outlet boundary, apply a pressure condition to represent blood flow exiting the artery.
• Wall Conditions:
  • Set the walls of the artery to “no slip” conditions to ensure realistic fluid dynamics.

Step 4: Mesh Generation

• Create Mesh:
  • Navigate to the mesh section and create a mesh for your model. A finer mesh may be necessary in the stenosis region to capture details accurately.
• Refine Mesh:
  • Use the adaptive mesh refinement feature to ensure that the critical areas have enough detail for accurate simulation results.

Step 5: Running the Simulation

• Set Up Study:
  • Choose a time-dependent or stationary study based on your analysis needs.
• Run Simulation: Click on the run button to start the simulation. Monitor the solver for any errors or warnings.

Step 6: Analyzing Results

• Post-Processing:
  • Once the simulation completes, use the post-processing tools to visualize the flow patterns.
  • Create plots for velocity, pressure, and streamline visualizations.
• Evaluate Results: Analyze the impact of stenosis on blood flow dynamics by comparing results with different stenosis severities.

Conclusion

In this tutorial, you learned how to model blood flow in renal artery stenosis using COMSOL. Key steps included setting up the model, defining material properties, and analyzing the results. This modeling approach can be applied to various biomedical scenarios, facilitating better understanding and treatment of vascular conditions. For further exploration, consider adjusting parameters or exploring different geometries to see how they affect blood flow.