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Vascular Endothelial Wall Shear Stress Calculator

Vascular Wall Shear Stress (WSS) is the tangential frictional drag exerted by flowing blood onto the endothelial lining of arteries.

Volumetric blood flow through the vessel lumen.

Internal lumen diameter (e.g. 3-4 mm for human coronary artery).

Dynamic blood viscosity (typically 3.2 to 4.0 cP at 37°C).

Calculated Result
24.95 dyn/cm²

Endothelial Wall Shear Stress

Wall Shear Stress (Pa)

2.495 Pa

Mean Velocity

31.2 cm/s

Reynolds Number

327.4

Calculation Breakdown

  1. Hagen-Poiseuille Wall Shear Stress (tau_w)4 * mu * Q / (pi * R³) = 24.95 dyne/cm² (2.495 Pa)
  2. Mean Blood Flow VelocityQ / (pi * R²) = 31.18 cm/s
  3. Vascular Reynolds Numberrho * v * D / mu = 327.4 (Laminar flow < 2000)

What Is the Vascular Endothelial Wall Shear Stress Calculator?

Wall shear stress is the biomechanical frictional force felt by endothelial cells lining blood vessel walls.

How Does the Vascular Endothelial Wall Shear Stress Calculator Work?

In laminar tube flow, the parabolic velocity gradient evaluated at the boundary multiplied by viscosity yields wall shear.

Vascular Endothelial Wall Shear Stress Calculator Formula & Variables

The core mathematical equation utilized by this calculator is expressed as:

au_w = rac{4 mu Q}{pi R^3} = rac{32 mu Q}{pi D^3}

Hagen-Poiseuille formula for wall shear stress in cylindrical tubes.

How to Use the Vascular Endothelial Wall Shear Stress Calculator

  1. Input volumetric blood flow in mL/min, internal lumen diameter in mm, and dynamic viscosity in cP.

Step-by-Step Example Calculation

Human Left Anterior Descending (LAD) Coronary Artery

Input Values:

bloodFlowMlMin:85
vesselDiameterMm:3.2
bloodViscosityCp:3.5
Worked Steps: Wall shear stress = 15.1 dyne/cm² (1.51 Pa), Mean velocity = 17.6 cm/s, Reynolds number = 169 (Laminar).

Understanding Your Result

Displays wall shear stress in dynes/cm² and Pascals along with mean velocity and Reynolds number.

Factors That Affect the Result

  • Shear stress is inversely proportional to the cube of vessel radius; minor vasoconstriction strongly elevates WSS.

When Should You Use This Calculator?

  • Atherosclerosis risk assessment, vascular stent hemodynamic design, and arterial remodeling studies.

Assumptions & Limitations

  • Assumes steady, laminar, Newtonian flow in rigid straight cylindrical tubes.

Frequently Asked Questions

Calculation Accuracy & Reference Note

Standard Hagen-Poiseuille biomechanical model.

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