Using the Internet, read about the Womersley number () and answer the following questions. a. Is

Using the Internet, read about the Womersley number (α) and answer the following questions.

a. Is α dimensionless? How do you know? Show that all the units in fact cancel out.

b. Like other independent π-groups, α is the ratio of two forces. Of what two forces is it the ratio?

c. What does the velocity profile in a blood vessel look like for α ≤ 1? For α ≥ 10?

d. What is the aorta, and where in the human body is it located? What is a typical value for α in the aorta? What might you conclude about the velocity profile there?