Passage
The flow of blood through the human body is typically laminar, but in certain conditions, as when blood flows through the aorta during a period of heightened physical activity, the flow can become turbulent. Blood flow can also become turbulent in abnormal cases in which the passage of blood is obstructed by constrictions within the blood vessel. The energy generated by blood turbulence creates sound vibrations that can be heard with a stethoscope.Using the technique of laser Doppler velocimetry, researchers recorded the blood velocity v at a point in the aorta of an experimental subject at different times during aerobic exercise. Table 1 shows the blood velocities observed over a 400 ms time interval.Table 1 Blood Velocity within the Aorta of an Experimental Subject (mean velocity v̅ = 101 cm/s)

Turbulent kinetic energy (TKE) is the kinetic energy per unit mass associated with turbulence within flowing fluids and is defined as:

Equation 1where σ_v is the standard deviation of the fluctuating fluid velocities at a point within the turbulent flow.Reynolds number Re is the quantity that ultimately measures whether a flow is turbulent or laminar. Re is defined in terms of the fluid density ρ, mean velocity of the flow v̅, conduit diameter d, and dynamic viscosity η of the fluid, as given by:

Equation 2In the context of blood flow, d is the diameter of the blood vessel, and blood has a fluid density of about 1,060 kg∙m⁻³ with a dynamic viscosity of about 0.003 kg∙m⁻¹∙s⁻¹.
-The blood leaving the aorta reaches the circle of Willis, a collection of arteries that supplies blood to the brain. Assume that it takes 600 ms for blood to reach the circle of Willis and that its average velocity is reduced to 61 cm/s. What is the average acceleration experienced by the blood?
A)−67.0 cm/s²
B)−0.670 cm/s²
C)0.670 cm/s²
D)67.0 cm/s²

Ideal Fluids Are Used to Model the Behavior of Fluids

Multiple Choice

Correct Answer:VerifiedUnlock this answer nowGet Access to more Verified Answers free of chargeAccess For Free

Correct Answer:
Verified
Unlock this answer now
Get Access to more Verified Answers free of charge