Flow Bifurcation in Cardiovascular Fluid Mechanics — Lesson 2

This lesson covers the concept of flow bifurcation in cardiovascular fluid mechanics. It explains how blood flows from the heart through aorta and further bifurcates into smaller arteries, arterioles, capillaries, venules, and veins. The lesson also discusses the role of fluid mechanics in plate formation, a cause for atherosclerosis, and heart attacks. It introduces Murray's law, which postulates that the design principle of bifurcations in biological systems is based on the minimisation of energy cost. The lesson further explores the general flow behaviour at bifurcations, the impact of bifurcation angles, and the occurrence of secondary motion or Dean flow. It concludes with the implications of flow separation and pulsatile flow in the circulatory system.

Video Highlights

00:28 - Introduction to flow bifurcation in cardiovascular fluid mechanics
05:10 - Introduction to Murray's law and its design principle based on cost function
19:24 - Understanding flow bifurcation based on Murray's law
28:40 - Explanation of flow bifurcation angles
34:56 - Do cardiovascular systems follow Murray's law?
39:34 - Exploration of secondary motion or Dean flow
43:23 - Discussion on flow separation and pulsatile flow

Key Takeaways

- Flow bifurcation is a crucial aspect of cardiovascular fluid mechanics, influencing the distribution of blood to different organs.
- Murray's law suggests that the design principle of bifurcations in biological systems is based on minimising energy cost.
- The velocity profile at bifurcations is typically skewed towards the inner wall, leading to secondary motion or Dean flow.
- Flow separation may occur near the outer wall, leading to lower shear stress and higher chances of plate formation.
- The pulsatile nature of flow in the circulatory system can lead to varying velocity profiles at different time instants.