Transport Phenomena in BME
Exercise 1 Blood flow through a stenosis
To examine how a stenosis affects the regional blood flow, we are to model the blood flow through an arterial segment with and without stenosis. The length of the arterial segment is 50 mm and the diameter of its inner lumen is 3 mm. First model the case without stenosis. For the disease case, consider the stenosis is at the midway of the flow path and its geometry can be approximated as a semi-circular cross section with a radius of 0.75 mm (the radius of the fillet is 0.5 mm). With axi-symmetry and laminar flow assumptions, we consider the blood has the following physical properties:
1Blood density (ρ) = 1,050 kg/m3
2 Dynamic viscosity (µ) of the blood = 3.5 x 10-3 Pa-sec or 3.5 cp
The pressure at the inlet of the arterial segment is at 80 mmHg (10.6 kPa), which drops to 60 mmHg (8 kPa) at the outlet. We are to consider three reference locations: Positions 1, 2, 3 are at 12.5, 25, and 37.5 mm respectively from the inlet of the arterial segment.
1. Use color contour plots to map out the velocity in the entire lumen. Use zoom-in view to highlight
the changes in the region near stenosis
2. Make streamline plots for the entire domain, then use zoom-in view to highlight the changes at
regions before and post the stenosis.
3. Plot the velocity profiles at Positions 1, 2 and 3
4. Use vector plots to show the variation in fluid velocity along the diameter at Position 1, 2, and 3.
5. Plot the shear stress profiles at Positions 1, 2 and 3
6. Plot the pressure drops from the inlet to the outlet
Compare each of the results between the stenosed and non-stenosed case, discuss how the stenosis affect the flow parameters.
