1. Answer three questions. Minimum 350 Words1. How has the Int.docx

1. Answer three questions. Minimum 350 Words
1. How has the Internet and use of communication impacted the
outcome of war(s)?
2. In what ways can a personal homepage help people to
construct and present a positive identity for themselves? What
kinds of problems could result from people presenting false or
misleading identities on their homepages? What can be done to
encourage more people to build personal homepages, and to
provide the necessary access to more people? (Optional)
Provide a link to your personal homepage, if you have one and
you wish to share it with the class. You may also wish to tell us
a little bit about your homepage and what purpose it serves for
you.
3. Provide the URL and a brief review of at least one site that
discusses the development of a personal web site OR methods of
communicating on the Internet. Did you learn anything new?
Were you surprised by any of the information presented on the
site? How do sites likes these impact Internet use?
2. Respond to the following discussion. Minimum 150 words
1. How has the Internet and use of communication impacted the
outcome of war(s)?
This question has always been a reflecting point for myself.
Being in the Air Force and working in communication I have
often thought how strange it would be for commanders not to be
able to commutate with troops that are in another geographical
area. The outcome of a battle would not be readily available
before the civil war. This can delay the correct orders reaching

a unit. Furthermore the negative effect on moral of being
separated from your family has greatly diminished. While I was
deployed I felt connected to family and friend because I could
just use skype. There was no wondering how anyone was doing
and my family worried less as result also.
With the ease of access to news it has brought a new front to the
war. Leaders are constantly finding themselves at odds with
members of the media. Not only because of what they say but,
also that their movement is being aired. This facet of the fight
forces leaders to hold a narrative close to the host county’s
(Hardy, 2013).
2. In what ways can a personal homepage help people to
construct and present a positive identity for themselves? What
kinds of problems could result from people presenting false or
misleading identities on their homepages? What can be done to
encourage more people to build personal homepages, and to
provide the necessary access to more people? (Optional)
Provide a link to your personal homepage, if you have one and
you wish to share it with the class. You may also wish to tell us
a little bit about your homepage and what purpose it serves for
you.
A personal homepage can market an induvial. The identity
(positive or negative) is mostly defined by the narrative of the
personal homepage (Personal Home Pages and the Construction
of Identities on the Web, 2014). Depending on the purpose of
the homepage it will effect what the problems that can arise
from presenting misleading information. If the page is used to
list credential possibly for potential employers this would pose
the same problems as lying on a resume. If one is trying to look
for credible people to cite it could also damage the research
done if their falsifying credentials. The use of social networking
cites makes it easy to have a pseudo homepage. Most
processionals are highly encouraged to use LinkedIn.

3. Provide the URL and a brief review of at least one site that
discusses the development of a personal web site OR methods of
communicating on the Internet. Did you learn anything new?
Were you surprised by any of the information presented on the
site? How do sites likes these impact Internet use?
For my URL I choose https://collegeinfogeek.com/personal-
website/. This goes into detail about how to create your own
personal website. I know must what one must do to get a
website however, I am unfamiliar with how you actually build
one. Luckily, this goes into how to use WordPress to create a
website. For someone like me this is more practical than
learning how get down to the nitty gritty and use HTML. Sites
like these self-help pages are great for helping everyone who
has access to the internet. I would say the impact is there is
more traffic since it is easier to just google something and learn
to do it rather than looking for the information in a book.
-Bill
Hardy, Q. (2013, June 19). Military And The Internet. Retrieved
March 19, 2018,
from https://www.forbes.com/2009/10/16/internet-drucker-war-
intelligent-technology-military.html#258f15aa7bc5
Personal Home Pages and the Construction of Identities on the
Web. (2014). Retrieved March 19, 2018, from http://visual-
memory.co.uk/daniel/Documents/short/webident.html
3. Respond to the following discussion. Minimum 150 words
A#1: Today, communication is made on real time over the
internet, one example could be drones. Military drones could fly
thousands of miles away and send information over the internet
instantaneously and decision makers could decide on their
verdicts. The same thing is with radio communication. Voice
over Internet Protocol (VoIP) is another example of instant
communication available almost for everyone. These tools could
give great benefits on the realm of a battlefield. Information
regarding weather, location (Google Maps is the leader in this

area), on real time could make the difference between winning
or losing a war. In our days the battlefield has become
virtual and "it is no longer fought on the ground but also on the
web" and unfortunately "any willing person can become a
belligerent in war, not just by fighting, but also by
instantaneously transferring information, money, or technology"
(Turitto, 2010).
A#2: Anyone could make his/her own webpage(s). The
technology is accessible, cheap and fast. If a person wants to
create his/her own page he/she doesn't need to be a computer
geek, because there are specialized companies or people who
can do that for money. If a person presented false information
that could happen for two reasons: that person doesn't have
many knowledge about what he or she posted or that person did
that on purpose. Both are dangerous and could hurt other
people. Some people will be misled from direction of some
webs or change their way of thinking. In the last case
propaganda over the internet could have a tremendous impact on
people, either in a positive way or a negative way. The best way
to encourage people to build their own web(s) is providing the
benefits of doing that. I don't have a personal webpage, but I am
thinking that in the near future I will make one. The idea of my
homepage is to share opinion about we could create a better
word by socializing more.
A#3: The URL is:
https://www.quora.com/What-are-the-benefits-of-having-a-
personal-website
On this web I found interesting points of view, such:
"When you have a personal website, it says to others that you
are a creative individual and are technologically advanced"
"Having a personal website though gives you an opportunity to
separate yourself from the rest of the pack",
"Personal websites also give you control to promote whatever
message you want to spread about yourself".
I learn that I could be different that most of the people, just
because there are few people with their own website and I was

surprised in a very nice way that I could be in charge of my
messages when I will post it on my own web. Each personal
website is like a voice, but many voice make a choir, which
means is a much powerful sound than a singular voice. In the
mean time a web could be connected to another(s) and the
message from that site could have more weight for readers.
References
Turitto, J. (2010). Understanding Warfare in the 21st Century.
Retrieved from http://www.iar-gwu.org/node/145
1
Preparing a Lab Report for ENG590
A scientific report usually consists of the following sections:
1. Title
2. Introduction
3. Method
4. Results
5. Discussion
6. Conclusion
7. Bibliography
Title
The title should be less than ten words and should reflect the
factual content of the lab report
and can be the same as the title on the lab sheet.

Introduction
The introduction defines the subject of the report. It must
outline the aims and objectives for
the experiment performed and give the reader sufficient
background to understand the rest of
the report. Care should be taken to limit the background to
whatever is pertinent to the
experiment. A good introduction will answer several questions,
including the following: Why
was this study performed?, What knowledge already exists
about this subject? , What is the
specific purpose of the study?
Method
As the name implies methods and equipment used in the
experiments should be reported in
this section. The difficulty in writing this section is to provide
enough detail for the reader to
understand the experiment without overwhelming him or her.
Generally, this section attempts
to answer the following questions: What materials were used?,
How were they used?

Results
The results section should present the data from the
experiments. The data should be
organized into tables, figures or graphs. All figures and tables
should have descriptive titles
and should include a legend explaining any symbols,
abbreviations, or special methods used.
Figures and tables should be numbered separately and should be
referred to in the text by
number, for example: Figure 1 shows that the acceleration at
different times.
Discussion
This section should not just be a restatement of the results but
should emphasize interpretation
of the data. What do the results show? Do they agree with
theory? How significant are the
errors in your measurements?
Conclusion
In the conclusion you should summarise what has been done and
the results which have been
obtained. How do they meet your original aims?

Bibliography
This section lists all articles or books cited in your report.
The following pages contain a sample lab sheet followed by an
example of a lab report.
2
LAB SHEET - VISCOSITY OF GLYCERINE
Aim:
To measure the viscosity of glycerine using Stokes' method in
which steel balls are allowed to
fall through glycerine.
Theory:
(i) If a body of mass m falls through a viscous fluid, it will
accelerate until
the combination of the viscous force (or drag) FD, and the
buoyancy
force FB balance the gravitational force Fg (= mg)

FD + FB = Fg (1)
When this equilibrium is reached, the body continues to fall,
but at a
constant velocity, called the terminal velocity.
(ii) Archimedes' Principle states that the buoyancy force acting
on a body
immersed in a fluid is equal to the weight of the fluid displaced.
If the
body immersed is a sphere of volume V and radius r, the volume
of fluid
=
4
3
L
g (2)
(iii) Stokes showed that for a sphere of radius r moving through

viscous drag is
where v is the steady velocity.
S
, then the gravitational force is
Fg =
4
3
S
g (4)
(v) Substituting (2), (3) and (4) into (1)
4
3
L
g =

4
3
S
g
4
3
–
r2 = v
g)(2
9
LS
(5)
The terminal velocity v can be determined by measuring the
time t for steel balls to fall
through a fixed distance s
v =
t

s
(6)
Substituting this expression into (5) gives
t
s
g
r
)(2
9
LS
2
3
t

kr
1
So
2
(7)
Now we can see that, if the time t for steel balls of varying
radius r to fall at terminal velocity
through the fixed distance s can be measured, a plot of r2
against 1/t should yield a straight
line of slope k.
Rearranging (8)
s
gk
LS
9
experimental data are required for the
S

Procedure:
1. Drop a medium sized ball into the column of glycerine and
make a starting mark
close to the top of the column, but at a position at which the
ball has achieved
terminal velocity (ie constant velocity), and a finishing mark
close to the bottom. The
distance between the marks is the fixed distance s.
2. Now it is required to time balls of varying r when falling
through that distance s
between the two marks.
Measure the diameter D of each ball with a micrometer before
dropping it into the
glycerine and measuring t. Take about 8 readings of t for a wide
range of r.
3. Plot a graph of r2 versus
t
1
and determine a value for the slope k (without

uncertainties).
4. To determine the density of the steel balls, and because all
balls were manufactured
from the same melt, it is necessary only to measure mass and
volume of one large
hydrometer.
Compare the
Note the temperature dependence
and record the temperature at which this experiment was
performed. Note also that the
viscosity of glycerine is very dependent on water content.
(8)
)(2
9
where
LS

g
s
k
4
EXAMPLE LAB REPORT - VISCOSITY OF GLYCERINE
Introduction
Viscosity is an important physical property of all fluids which
relates to the level of
friction a fluid experiences when it flows. An example of a fluid
with a high viscosity
is syrup which requires more effort to stir than a low viscosity
fluid such as water.
Higher viscosity fluids require more energy to overcome the
higher levels of friction
when they flow. It is therefore important to know the viscosity
of a fluid which is
being pumped through a pipeline. Measurement of viscosity is

also important in the
petroleum industry where the viscosity of crude oil is strongly
related to its
composition [1].
An instrument which is used to measure fluid viscosity is called
a viscometer. There
are a number of different viscometers which are in use [2]. Here
we use a falling
sphere viscometer which, as the name suggests, involves a
sphere falling through the
liquid being measured. The principle behind the falling sphere
viscometer is that
when the sphere is falling there are three forces acting on it.
The first is its weight and
the second is the drag force and the third is the buoyancy force.
This is shown in
figure 1.
Figure 1: The forces acting on a sphere falling through a liquid.
Taken from the lab
sheet.
The buoyancy force is known to be equal to the weight of fluid
displaced and acts in

the opposite direction to the sphere’s weight. The buoyancy
force can be found using
�� =
4
3
��3��
liquid being tested, and g is
the acceleration due to gravity. The weight of the sphere is
simply its mass multiplied
by gravity. Although accurate balances are available to measure
the mass of the
sphere, we instead express the weight in terms of the volume of
the sphere and the
density of the sphere to be consistent with the approach for the
buoyancy. In this way
the weight of the sphere is
�� =
4
3
��3��
sphere was determined by
George Gabriel Stokes in 1851 [2] and is given by

�� = 6��
e opposes the
direction of motion.
When the sphere is falling at its terminal velocity the sum of the
drag and the
buoyancy forces must be equal to the weight of the sphere. This
gives
4
3
��3�� + 6�� =
4
3
��3�� .
5
If the sphere is falling at its terminal velocity and it travels a
distance s in time t, then
we can write v = s/t and re-arrange the above equation to give
r2 = k/t , where � =
9
2
��

(��−��)�
.
Method
The experiment was conducted using a large measuring cylinder
containing glycerol.
Initially the density of the liquid and the balls were obtained.
The density of the
glycerol was found using a hydrometer. This was placed in the
cylinder and the
density read from the scale on the hydrometer at the surface of
the glycerol. Secondly
the density of the spheres was found.. The spheres which were
used were all bearings.
They all had different radii, but were made from the same
material. The density was
found by measuring the radius and the mass of one of the balls.
This was done for the
largest ball to minimise errors.
The next step was to determine how quickly the ball bearings
reached their terminal
velocity. This was done by dropping a medium sized ball into

the liquid and watching
its progress. Once it was judged that the ball had reached a
constant velocity, a
horizontal line was drawn on the measuring cylinder using a red
marker pen. A
second line was drawn near the bottom of the cylinder.
The following procedure was then followed with all the ball
bearings.
1. The radius of the ball bearing was measured using a
micrometer.
2. The ball bearing was dropped into the measuring cylinder of
glycerine.
3. The time taken for the ball to travel between the two marked
lines was
recorded.
This procedure was repeated for each of the ball bearings.
Finally the distance
between the two red lines on the measuring cylinder was
measured suing a ruler.
Results
When the steel balls were dropped into the cylinder they
appeared to reach their

terminal velocity within the first 30 cm. The time was,
therefore, recorded between a
line marked on the cylinder 30 cm below the surface and a
second line 50 cm below
the first. The measured diameters, d, of the steel balls and the
time taken for them to
fall through 0.5 m of glycerine are shown in table 1. The
calculated value of (1/r)2 is
also shown. The diameter was measured with a set of callipers
and the error in the
reading was ± 0.05 mm. The time was measured with a digital
stop watch with an
error of ±0.05 s.
d (mm) t(s) d(m) r(m)
r-2(m-2)
1.1 72.8 0.0011 0.00055 3310000
1.9 18.2 0.0019 0.00095 1110000
3 8.1 0.003 0.0015 444000
4.1 4.6 0.0041 0.00205 238000
4.8 3 0.0048 0.0024 174000
9.8 0.9 0.0098 0.0049 41600

15.3 0.2 0.0153 0.00765 17100
20.2 0.2 0.0202 0.0101 9800
6
Table 1: The diameter and radius of the steel balls and the time
taken for them to fall
through 0.5 m.
The density of the steel balls was found using the largest of the
steel balls. Its mass
was measured as 31.5 ± 0.05 g. The density of the steal is given
by
�� =
�
�
=
3�
4��3
=
3×0.0315
4×3.14×0.01013
= 7303 kgm-3.

Figure 2 shows a graph of the time plotted against 1/r2. The
best fit straight line
through the points has a gradient of k = 2x10-5 s.m2. All of the
data points lie on or
close to this line suggesting that the relationship is linear.
Using equation (9) this
gives the viscosity as
55.0
5.09
81.9)10007303(1022
9
)(2
5
s

gk
LS
-1s-1.
Figure 2: Graph of t plotted against 1/r2.
Discussion
The value found for the viscosity of glycerine was 0.55 kgm-1s-
1. This is considerably
lower than the tabulated value of 1.5 kgm-1s-1 [3]. The error in
measuring the diameter
of each ball was fixed at ± 0.05 mm. For the smallest ball this is
approximately a 5%
error. The error reduces to 0.25% for the largest ball. The error
in recording the time
from the stop watch is ±0.05 s, but this does not include the
reaction time of the
person using the stop watch. This was estimated to be 0.2s and
explains why the time
for the two largest balls is the same. This gives a percentage
error or 100% for the
largest two balls and an error 0.3% for the smallest ball. There

is a large error in
measuring the time for the larger balls and in measuring the
radius for the smaller
balls. The results for the middle balls should give the most
accurate reading. The
density of steal was found using the largest ball to give the most
accurate value.
Most of the points in figure 1 lie on or very close to the bet-fit
line which suggests
that the value for the viscosity should be fairly accurate. The
viscosity of glycerol
changes rapidly with temperature and with water dissolved in
the glycerol [4]. The
difference between the tabulated value and the value found here
could be due to this.
If the experiment was done again, the temperature should be
recorded and a new
sample of glycerine should be used to make sure there is no
dissolved water. It would
be best to only use balls with a diameter between 3 and 5 mm
and to make several
measurements for each ball.
y = 2E-05x - 1.0795

-10
0
10
20
30
40
50
60
70
80
0.E+00 5.E+05 1.E+06 2.E+06 2.E+06 3.E+06 3.E+06 4.E+06
t
(
s)
(1/r)2 (m-2)
7
It is difficult to know when the ball reaches its terminal
velocity. Measurements could

be taken with a lower start line to see if this changes the value
for the viscosity.
Conclusions
A value of 0.55 kgm-1s-1 was found for the viscosity of
glycerol. This is about a third
of the tabulated value. This may be due to dissolved water in
the glycerol, or a
difference in the temperature, which was not recorded. The
result showed it is
possible to measure viscosity in this way. Some suggestions
were made to improve
this experiment.
Bibliography
[1] Wernera, A, Beharb, J. de Hemptinnea, J. C. and, Behara,
E. ‘Viscosity and
phase behaviour of petroleum fluids with high asphaltene
contents’, Fluid Phase
Equilibria, 147, 343–356, 1998.
[2] http://en.wikipedia.org/wiki/Viscometer. Accessed
20/9/2012.
[3] Brown, J. Y. and Heath W. L. Table of Physical Constants.
Paragon Press,

London 1985.
[4]
http://www.binacchi.com/Utilites/useful/glycerine%20viscosity.
pdf. Accessed
22/07/2010.
http://en.wikipedia.org/wiki/Viscometer
http://www.binacchi.com/Utilites/useful/glycerine%20viscosity.
pdf
E
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Energy Engineering
Performance of a Heat Pump
Introduction
Aim
The aim of this laboratory is for you to understand the operation
and some of the characteristics of a heat pump.
Equipment

Figure 1: The configuration of the heat pump showing the
position of the thermometers (T1 – T9), pressure gages
(p1 and p2), and the flow meters. The position of the state
points (1 – 4) corresponding to the temperature
measurements T1 – T4 are also shown on a pressure enthalpy
chart.
The Hilton Air and Water Heat Pump is a small-scale
demonstration unit designed especially for educational
purposes. Heat may be exchanged from either atmospheric air
or to/from water supplied from the cold mains
water supply. The work input is in the form of electrical energy
supplied to a hermetically sealed compressor.
The unit comprises the following components:
Compressor: Hermetically sealed and fitted with an oil-cooling
coil. The swept volume is 15cm3. The
operating speed is approximately 2800rev/min. It is powered by

an electric motor.
Condenser: This consists of concentrically coiled tubes, with
the refrigerant flowing through the inner tube
and the cooling water flowing through the annular space. The
system is thermally insulated.
Expansion valve: This is thermostatically controlled to provide
a small amount of superheat at the compressor
inlet (to prevent liquid entering the compressor).
Evaporators: This consists of concentrically coiled tubes, the
refrigerant passing through the inner tube and
water (which acts as the heat source), passing through the
annular space.
Refrigerant: R134a (tetrafluoroethane CH2F-CF3).
��
��
��
p-h diagram
Specific Enthalpy
Pressure
1
2

3
4
Circuit Diagram
T1, p1
T2, p2 T3
T4
T5 T6
T7 T8
T9
Compressor
Throttle
Condenser
Evaporator
��
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Energy Engineering
These are shown in figure 1, which also indicates the position
of state points 1, 2, 3 and 4 in the refrigerant and
also on a p-h diagram.
Instrumentation
• An electricity meter for measuring the power input to the
compressor,
• Glass thermometers at ten temperature measuring locations,
• Two pressure gauges; one for measuring the compressor inlet
pressure, and the other the compressor outlet
pressure,
• Two water flow rotameters; one for measuring the water flow
to condenser, and the other to the compressor
and the evaporator,
• A rotameter for measuring the refrigerant flow rate at the inlet
to the expansion valve (or throttle).
The position of these instruments is indicated in figure 1.
Background and Analysis
The machine is called a refrigerator when the desired effect is

to remove heat from the low temperature
reservoir, and is called a heat pump when the desired effect is to
supply heat at the high temperature; both
processes occur simultaneously, the only difference is the
desired effect. In either case, the useful heat transfer
is usually greater than the work input, so the “efficiency” of the
machine is called a coefficient of performance.
For a heat pump, the coefficient of performance is the ratio of
the heat transfer rate to the high temperature
reservoir
�� to the rate of work input �� ,
COP��
��
��
,
and for a refrigerator, the coefficient of performance is the ratio
of the heat transfer rate to the low temperature
reservoir
�� to the rate of work input �� ,
COP� �
��
��
.

If there are no other heat transfers, then
��
�� ,
and therefore
COP��
��
��
� COP� � 1.
Procedure
• Turn on the two water supply taps.
• Adjust the water flow by means of the needle valves on the
rotameters to read maximum values.
• Switch on the power supply and wait for equilibrium
conditions to be reached.
• Record all pressure, temperature and flow rate measurements
(see table at the back of the lab sheet).
• Measure the time for one revolution of the electricity meter.
E
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Energy Engineering
• Reduce the condenser water flow rate to about 7.5g/s. This
will cause the condenser pressure to rise to a
maximum of about 1400kN/m2 (gauge pressure).
• Adjust the evaporator water flow to keep T4 the same as in the
first test. Remember that an increase in
evaporator water flow will raise the evaporator temperature.
• Wait for stable conditions, and record all measurements.
• When finished, turn off the power supply but leave the water
taps on.
• Record the atmospheric pressure on the laboratory barometer.
Analysis of Results
The coefficients of performance can be calculated using the heat
transfer rates based on the water flow or the
refrigerant flow. Since heat is transferred from the water to the
refrigerant (or vice versa), the calculated heat
transfer rates should be equal in magnitude, but opposite in
sign.

Performance based on the water flow
Work input to the compressor
In the electricity meter, 1kWh causes 1662/3 revolutions of the
disc. Therefore one revolution indicates the
consumption 6 � 10��kWh. If this is consumed in time t (s),
the electrical power �� can be calculated as
�� 6 � 10
��
3600
�
.
This is the power input to the motor driving the compressor, not
the power input to the compressor itself. If we
assume an efficiency of 80%, then the actual power from the
compressor is
�� 0.8 �� .
Heat transfer rate in the compressor
Applying the steady flow energy equation (SFEE) to the
compressor water flow gives
�� ! � �� "#$ % #&' � �� (!)"*$ % *&',
where �� is the water flow rate through the compressor
(note we need to change all flow rates to kg/s, i.e. the

reading in g/s divided by 1000), and (!) � 4.19kJ/kgK is the
specific heat capacity of water.
Heat transfer rate from the cold temperature reservoir
(evaporator)
evaporator water flow gives
�� "#2 % #3' � �� (!)"*2 % *3',
where �� is the water flow rate in the evaporator.
Heat transfer rate from the high temperature reservoir
(condenser)
condenser water flow gives
�� "#4 % #$' � �� (!)"*4 % *$'.
Coefficients of performance
The coefficient of performance of the heat pump based on the
water flow is given by
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Energy Engineering
COP��
��
��
.
The coefficient of performance of the refrigerator based on the
water flow is given by
COP5 �
��
��
.
In calculating the COPs, ignore the sign of the heat transfers.
Performance based on the refrigerant flow
Plotting the cycle diagram
The thermodynamic cycle can be plotted on the pressure-
enthalpy (6-#) diagram for R134a provided as shown in
figure 2. Note that you should join up state points 1-4 to show
the thermodynamic cycle.

Figure 2: Pressure-Enthalpy chart. State points are shown as
crosses (black), and temperatures are shown as
temperatures circles (red); the short(red) lines attached to these
circles are lines of constant temperature. The two
long horizontal lines (blue) are lines of constant pressure, the
vertical lines (green) are lines of constant enthalpy.
To find your enthalpy values from the chart you need to
1. Convert the readings of gauge pressure 67 and 68 into
absolute values by adding atmospheric pressure.
E
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Energy Engineering
2. Plot state points 1 and 2 in the superheat region using values
of 67, *7 and 68, *8. Join points 1 and 2 to
represent the compression process.

3. Locate *� on the constant pressure line (horizontal)
corresponding to 68 (it’s expected to be on or near the
saturated liquid line); this is state point 3. The horizontal line
between points 2 and 3 represents cooling
and condensation at constant pressure.
4. Draw a vertical line downwards from point 3 until it reaches
an isotherm corresponding to *9. Inside the
saturation dome an isotherm (line of constant temperature)
corresponds to a horizontal line of constant
pressure. This vertical line represents the (constant enthalpy)
throttling process between state points 3
and 4 (no heat transfer and no work done).
5. Notice that the pressure at point 4 is higher than at point 1,
mainly because of the flow resistance of the
non-return valve between the evaporator and the compressor.
Join points 4 and 1 with a straight line
representing the evaporation process.
6. Read the values of specific enthalpies #7, #8, #�, and #9
from the 6-# diagram, noting that #9 � #�.
Rate of work done by the compressor
Appplying the SFEE to the refrigerant flow through the
compressor gives

�78 �� 78 � �� "#8 % #7',
where �� is the refrigerant flow rate (again in kg/s), and
�78 � %
�� ! (evaluated from the water flow).
Therefore, the rate of work done compressing the refrigerant
vapour is given by
�� 78 � �� "#8 % #7' �
�� !.
Heat transfer rate through the condenser
The heat transfer rate from the refrigerant is given by
�8� � �� "#� % #8'.
Heat transfer rate through the expansion valve
There are no heat or work transfers in the throttling process, so
#� � #9.
Heat transfer rate through the evaporator
The heat transfer to the refrigerant is given by
�97 � �� "#7 % #9'.
Coefficients of performance
The coefficient of performance of the heat pump based on the
refrigerant flow is given by

COP��
�8�
�� 78
.
The coefficient of performance of the refrigerator based on the
refrigerant flow is given by
COP5 �
�97
�� 78
.
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In calculating the COPs, ignore the sign of the heat transfers.
Discussion

How do your results relate to theory?
Discuss and suggest reasons for the differences.
What are the sources of error in the experiment? Could these be
reduced or eliminated?
Quantify the effect of the errors on your results.
Conclusions
Summarise the main points from your discussion.
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Energy Engineering
Use this table to record your results
Measured quantities Units Test 1 Test 2
*7 °C
*8 °C
*� °C

*9 °C
*3 °C
*2 °C
*& °C
*$ °C
*4 °C
67 bar
68 bar
Mass flow rate
of refrigerant (�� )
g/s
Mass flow rate of
water to evaporator (�� )
g/s
Mass flow rate of water to
condenser/compressor (�� )
g/s
Time for one revolution of the
electricity meter (�)
s

Atmospheric pressure = bar
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Derived quantities
Enthalpy Units Test 1 Test 2
#7 kJ/kg
#8 kJ/kg
#� kJ/kg
#9 kJ/kg
Test 1 Test 2

Based on the
water flow
Based on the
refrigerant flow
Based on the
water flow
Based on the
refrigerant flow
Compressor power
�� , �� 78
(kW)
Heat transfer is the
compressor
�� !,
�78
(kW)
Heat transfer in the
condenser
��,
�8�
(kW)

Heat transfer in the
evaporator
��,
�97
(kW)
COP��
(no units)
COP�
(no units)
Academic Year 2017/18
ENG590 Energy Engineering
Online Coursework

Deadline For Submission: Midnight 28th March 2018
Submission Instructions Please upload your report to Turnitin
dropbox on Moodle
Instructions for completing the
assessment:
Not applicable
Examiners: Dr Jovana Radulovic, Dr James Buick
2017-18 Page 1 of 1
Submit a lab report for either the ‘Laminar Turbulent’ or ‘Heat
Pump’ lab. The lab sheet for both of the labs
is available on Moodle. You will find information on how to
write a lab report, and an example lab report in
the file ‘Example lab report’, also on Moodle.
The lab report should be submitted through Moodle in the
designated dropbox before the deadline stated
on the front page.
The marking scheme for the lab report is given below.
Acquiring raw data 15%

Introduction, method and experimental technique 15%
Analysis (including units, calculations, tables, graphs and charts
as appropriate) 30%
Discussion and Conclusion 15%
Structure and Clarity of Report 5%
Error analysis and insight 10%
Insight and Understanding 10%
Your coursework mark is calculated as RM x AM, where
RM is the mark you receive for your lab report according to the
marking scheme above; and
AM is your attendance mark which is 0.25 for each lab you
attended (eg. 1 if you attend all four, or 0.75 if
you only attend three).
In addition you will have the opportunity to submit a formative
lab report during the unit. This submission is
optional. If you do submit a lab report by 24 January 2018, it
will be marked and you will receive feedback.
The mark will not count towards your final mark for the unit;
however, the feedback will be useful to
improve your report for the final submission.

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