1. Microflows in the Human Body
Jeff French
MAE 5130

2. Purpose Gain a better understanding of bloodflow
Compare to Newtonian fluids
Illustrate effects of health ailments

3. What is blood? Suspension of plasma (liquid) and blood cells
Viscosity depends on red blood cell count, hematocrit and rouleaux
For these reasons, blood is considered non-Newtonian and is modeled by the Herschel-Bulkley models

4. Navier-Stokes and blood
Blood is a non-Newtonian fluid
The Navier-Stokes equations reduce to:
Which is very similar to the Hagen-Poiseuille Flow:

5. Velocity Profiles
For blood, the profile is similar to:

6. Velocity Profiles
A Newtonian comparison:

7. Reynolds Number and Shear Stresses
Reynolds numbers for blood vessel diameters and high velocity:

8. Reynolds Number and Shear Stresses
Wall shear stresses are proportional to blood vessel diameter

9. Bits and Pieces Many assumptions for blood flow
Individual characteristics affect all aspects
Analyses were performed under healthy, usual characteristics

10. Questions?