Chem 110A
Midquarter ANSWERS Name_Student ID_VERSION A ANSWERS Midquarter Exam November 6, 2009 Chemistry 110A Professor McCurdy
Instructions: You may use only a pencil or pen. You may have one sheet
Problem Set #2
Due Thursday 4/9/2015
1. The Second Law of Thermodynamics is typically written in the form dSdQ/T, where S is entropy,
Q is the total heat flow into a system and T is temperature. The s
Chem 110A Name_ Student ID_
Midquarter Exam November 6, 2009 Chemistry 110A Professor McCurdy Instructions: You may use only a pencil or pen. You may have one sheet of equations that you have prepared
Chem 110A Name_Answers_ Student ID_
Second Midquarter Exam November 25, 2009 Chemistry 110A Professor McCurdy Instructions: You may use only a pencil or pen. You may have one sheet of equations that y
ME 144: Heat Transfer
Convection Relations for External Flows
J. M. Meyers
Empirical Correlations
Generally, convection correlations for external flows are determined experimentally using
controlled l
ECH 142 NAME: vcm NC)
Quiz 1 3"
(B Form)
#1) (5 points)
The local Nusselt number for turbulent heat transfer over a plate is
given by
NW = 0.0290 (NW) (M9043
, where x is the distan
SolutionsManual
to accomparry
Heat Transfer
tenth edition
J. P. Holman
southernMethodisttJniversity
Chapter I
1-1
LT-
(39oox9-022
=
(0.2x0.6) 625oc
l-2
q _(0.035X85)
-_ , 22f85 llt'm2
A
0.13
= g2,3g6
ECH 142
Chemical Engineering Heat Transfer
HOMEWORK 3 SOLUTION
Problem 1
The function of the extra clothing in winter is to trap a layer of stagnant air near the skin, thereby decreasing the effect
o
ECH 142
Problem Set #5
Due Thursday 4/30/15
1. A cylindrical steel rod with diameter 1.75 and length 18 is connected to steel plates at the boiling
point and freezing point of water, respectively (i.e
ECH 142
Problem Set #7
Due Thursday 5/14/15
1. Shown below is a diagram of a circuit board with dimensions 14cm x 8 cm, on which are located 16
integrated circuits (ICs) with cross-sectional dimension
ECH 142
Problem Set #4
Due Wednesday 4/22/15
1. An irregularly shaped object with an initial temperature of T0=60C is placed in a well-stirred batch
that is maintained at TB=70C. Next the same object,
ECH 142
Problem Set #6
Due Thursday 5/6/15
1.
In class we used separation of variables to derive the temperature field in a rectangular region. The
result was
T(x, y) = Bn sin(nx) sinh(ny) ,
n=1
with
ECH 142
Problem Set #3
Due Thursday 4/16/15
1. A spherical tank is to be used as a container for liquefied petroleum gas. The tank is to have a wall
comprised of two layers, as shown in the figure bel
ECH142 HW2 Solution, Spring 2013
1a
U 2
Br
kT
At room temperature, for water, =10-3 kg m-1 s-1 and k=0.6 W m-1K-11 W m-1K-1 for the sake of
estimation.
10 3 kg m s K U 2
kg s 2
= 10 4 U 2
1
1J 10K
m
ECH142 HW4 Solution, Spring 2013
1a
One-dimensional transient conduction:
T
2T
= 2
t
x
Scale variables: =
T Tref ~ x ~ t
;x = ;t =
T
T T 2
=
~
t
2 ~ 2
x
Divide by
2
:
2 2
=
~ ~ 2
t
x
1b
2
If
>
Homework #4
Due Monday, April 29th, 2013
In class (no late HW's accepted)
1. Consider one-dimensional transient heat conduction occurring over short times < L2/. At this
time scale, the characteristic
Homework #1
Due Tuesday, April 9, 2013
1. Use a material body control volume to
a. derive the continuity equation (conservation of mass). Clearly explain all steps.
b. Using your result from part a, c
Homework #2
Due Tuesday, April 16, 2013
1. a. For water at room temperature exposed to a roughly 10 C temperature change, determine
how large the velocity would have to be for Br > 1.
~
b. Justify the
Homework #3
Due Tuesday, April 23, 2013
1. A pipe has a single-layer wall of thickness r2r1 and thermal conductivity k1. To try to
prevent heat losses from the outside of the pipe, we add a second lay