This preview shows pages 1–5. Sign up to view the full content.
Today (11/03), lecture #19
1) Quiz #8
2) The cardiovascular system
Tuesday (11/08), lecture #20
Finish the cardiovascular system
Thursday (11/10), Exam #2
Bring your calculator. Material to study:
A) All lecture notes (lectures 1220). Study the slides and the notes
that were written on the board.
B) All concepts addressed in homework sets 4, 5, and 6.
HW Set #6
: The answers are available on Blackboard.
This preview has intentionally blurred sections. Sign up to view the full version.
View Full Document Hint for Problem 5 of Hw Set #5
k
g
j
y
y
x
a
i
xy
x
a
k
z
P
j
y
P
i
x
P
P
ˆ
ˆ
)
(
2
ˆ
)
(
2
ˆ
ˆ
ˆ
3
2
2
2
3
2
ρ
−
+
−
+
−
=
∂
∂
+
∂
∂
+
∂
∂
=
∇
dt
dV
z
V
y
V
x
V
x
P
g
x
x
x
x
x
µ
=
∂
∂
+
∂
∂
+
∂
∂
+
∂
∂
−
2
2
2
2
2
2
dt
dV
z
V
y
V
x
V
y
P
g
y
y
y
y
y
=
∂
∂
+
∂
∂
+
∂
∂
+
∂
∂
−
2
2
2
2
2
2
dt
dV
z
V
y
V
x
V
z
P
g
z
z
z
z
z
=
∂
∂
+
∂
∂
+
∂
∂
+
∂
∂
−
2
2
2
2
2
2
Use the NavierStokes equations for Cartesian coordinates
z
V
V
y
V
V
x
V
V
t
V
dt
V
d
z
y
x
∂
∂
+
∂
∂
+
∂
∂
+
∂
∂
=
And the derivative of the velocity field
To write the pressure gradient field
The homogeneity of flowing blood is dependent upon
vessel diameter
.
1) In large vessels
pulsatile flow
keeps blood cells suspended
and blood can be approximated as a homogeneous fluid.
2) In smaller vessels the erythrocytes move to the center,
leaving a plasma layer near the wall.
3) In capillaries the erythrocytes squeeze through the lumen
one at a time, thereby isolating the plasma into separate
units between the erythrocytes.
Blood is a suspension of
multiple components
and is not always
considered to be a
homogeneous fluid.
Homogeneous
Inhomogeneous
This preview has intentionally blurred sections. Sign up to view the full version.
View Full Document FahraeusLindqvist effect
: the viscosity of blood moving in a small vessel is
related to the vessel diameter. Erythrocytes become concentrated at the
center of the vessel during laminar flow.
Large velocity gradient near the wall pulls the long axis of erythrocytes parallel to the
direction of flow and forces them toward the center where the flow is more stable.
This is the end of the preview. Sign up
to
access the rest of the document.
This note was uploaded on 11/14/2011 for the course ECE 3820 taught by Professor Wang during the Fall '11 term at GWU.
 Fall '11
 Wang

Click to edit the document details