This preview shows pages 1–2. Sign up to view the full content.
Problems
371
following
fluids when
u'"
=
1 m/s:
atmospheric
air,
water,
engine
oil,
and
mercury. In each case the fluid temperature
is
27°e:
Conservation
Equations
and Solutions
6.11 Consider the control volume shown for the special case of steadystate conditions
with
v
= 0,
T
=
T(y),
and
p
= const.
~
r+
OTdy
oy
p;.
0 ~
+
op
dx
~
Pox
~.~
(a) Prove that
u
=
ti(y)
if
v
= 0 everywhere.
(b) Derive the xmomentum equation and simplify it as much as possible.
(c) Derive the energy equation and simplify it as much as possible.
6.12 Consider a lightly loaded journal bearing using oil having the constant properties
/k
= 10
2
kg/s·
m and
k
= 0.15 W/m
. K. If the journal
and the bearing
are
each maintained
at a temperature
of 40°C, what is the maximum temperature
in
the oil when the journal is rotating at 10 my's?
6.13 Consider a lightly loaded journal bearing using oil having the constant properties
p
= 800 kg/m
3
,
v
= 10
5
m
2
/s,
and
k
= 0.13 W/m·
K. The journal diameter is
75 mm; the clearanceis
0.25 mm; and the bearing operates at 3600 rpm.
(a) Determine
the temperature
distribution
in the oil film assuming that there is
no heat transfer into the journal and that the bearing surface is maintained
at
75°C.
(b) What is the rate of heat transfer from the bearing, and how much power is
needed to rotate the journal?
6.14 Consider
two large (infinite) parallel plates, 5 mm apart. One plate is stationary,
while the other plate is moving at a speed of 200 m/so Both plates are maintained
at 27°C. Consider two cases, one for which the plates are separated by water and
This preview has intentionally blurred sections. Sign up to view the full version.
View Full Document
This is the end of the preview. Sign up
to
access the rest of the document.
This note was uploaded on 12/06/2011 for the course CHE 234 taught by Professor Smith during the Spring '11 term at Clemson.
 Spring '11
 Smith
 Chemistry, pH

Click to edit the document details