Sunday, 27 April 2014
Sunday, 20 April 2014
AIRCRAFT PROPULSION
AIRCRAFT PROPULSION
JET ENGINE PERFORMANCE EXERCISE
Introduction
This exercise is concerned with a simple
jet engine and involves using
the NASA
EngineSimU program.
The program
accept
s
data about the engine such as compressor
pressure ratio, turbine inlet temperature and the altitude and speed of the aircraft, in which
the engine is installed. The fuel consumption and thrust from a jet engine depends upon
engine design and the operating
condition of the aircraft. The performance of a jet engine
has to be estimated at an early stage for the flight conditions for which the aircraft will be
used.
Further background on this will be found in the textbook ‘Gas Turbine Theory’ by Cohen,
Rogers
and Saravanamuttoo. A typical output is shown in the form of a performance map
on Fig.3.12. (In the fifth edition).
From: Cohen, Rogers and Saravanamuttoo ‘Gas Turbine Theory’
The calculations carried out by the CATU program
:
The CATU program
accep
t
s
the altitude and use empirical equations to determine the
corresponding ambient pressure and temperature.
The aeroplane Mach number is used with the above to calculate the stagnation temperature
and pressure. Next the stagnation pressure delivered by t
he intake is calculated using the
efficiency of the intake. The pressure and temperature rise through the compressor is
calculated and the combustion temperature is evaluated by means of a numerical scheme
which is equivalent to using the Rogers & Mayhew
‘Combustion temperature rise
-
fuel air
ratio chart’.
Following the combustion chamber the turbine calculation is carried out, knowing that the
power from the turbine has to be sufficient to drive the compressor and turbine mass flow is
the compressor mass
flow + the fuel flow.
The exhaust products from the turbine are expanded through the propelling nozzle which is
normally of the convergent type and the gross thrust from the nozzle is calculated.
The above information is used, with the intake momentum dra
g, to calculate the specific fuel
consumption, SFC or TSFC in the case of EngineSimU. This is the fuel flow rate divided by
the net thrust.
2
Using the NASA EnginSimU program
To use this program go
JET ENGINE PERFORMANCE EXERCISE
Introduction
This exercise is concerned with a simple
jet engine and involves using
the NASA
EngineSimU program.
The program
accept
s
data about the engine such as compressor
pressure ratio, turbine inlet temperature and the altitude and speed of the aircraft, in which
the engine is installed. The fuel consumption and thrust from a jet engine depends upon
engine design and the operating
condition of the aircraft. The performance of a jet engine
has to be estimated at an early stage for the flight conditions for which the aircraft will be
used.
Further background on this will be found in the textbook ‘Gas Turbine Theory’ by Cohen,
Rogers
and Saravanamuttoo. A typical output is shown in the form of a performance map
on Fig.3.12. (In the fifth edition).
From: Cohen, Rogers and Saravanamuttoo ‘Gas Turbine Theory’
The calculations carried out by the CATU program
:
The CATU program
accep
t
s
the altitude and use empirical equations to determine the
corresponding ambient pressure and temperature.
The aeroplane Mach number is used with the above to calculate the stagnation temperature
and pressure. Next the stagnation pressure delivered by t
he intake is calculated using the
efficiency of the intake. The pressure and temperature rise through the compressor is
calculated and the combustion temperature is evaluated by means of a numerical scheme
which is equivalent to using the Rogers & Mayhew
‘Combustion temperature rise
-
fuel air
ratio chart’.
Following the combustion chamber the turbine calculation is carried out, knowing that the
power from the turbine has to be sufficient to drive the compressor and turbine mass flow is
the compressor mass
flow + the fuel flow.
The exhaust products from the turbine are expanded through the propelling nozzle which is
normally of the convergent type and the gross thrust from the nozzle is calculated.
The above information is used, with the intake momentum dra
g, to calculate the specific fuel
consumption, SFC or TSFC in the case of EngineSimU. This is the fuel flow rate divided by
the net thrust.
2
Using the NASA EnginSimU program
To use this program go
http://www.grc.nasa.gov/WWW/k
-
12/airplane/engsimu.html
(make
sure that Java is enabled on your web browser).
Choose the turbojet option and
set the
program
for metric units.
(i)
Record the variation of the specific fuel consumption (SFC) wit
h the specific net
thrust (SNT) for an altitude of
7
000 meters, aircraft Mach number of 0.
8
, ideal intake
and nozzle, efficiencies of 0.
9
for the compressor and turbine, pressure loss of 0.03 in
the combustion chamber and efficiency of one, while varyin
g
the compressor pressure
ratio
from 6 to 9 in steps of one and the combustion chamber maximum
temperature
from 1
1
00K to 1
4
00K in steps of 100K. The SNT is to be calculated by
dividing
the
net thrust by the mass
airflow
rate.
Plot SFC .vs. S
NT
for these con
ditions using Excel or similar, producing a graph
similar to that
on the first page
.
[30%]
(ii)
Carry out a hand calculation for one of the conditions of the
above;
assume the
compressor and turbine
efficiencies
are isentropic.
Compare
your results of SFC and
SNT to the results produced by the
computer
program
. Explain the difference.
[30%]
(iii)
For three compressor pressure ratios and three combustion temperatures, vary the
Mach number
(at least three Mach numbers, one supersonic)
and altitude
(at least
three alti
tudes, one above 11km),
and plot the variation of SFC and SNT with the
Mach number and altitude
[20%]
(iv)
Discuss the effects of the variation of SFC and SNT with the Mach number and
altitude.
[20%]
12/airplane/engsimu.html
(make
sure that Java is enabled on your web browser).
Choose the turbojet option and
set the
program
for metric units.
(i)
Record the variation of the specific fuel consumption (SFC) wit
h the specific net
thrust (SNT) for an altitude of
7
000 meters, aircraft Mach number of 0.
8
, ideal intake
and nozzle, efficiencies of 0.
9
for the compressor and turbine, pressure loss of 0.03 in
the combustion chamber and efficiency of one, while varyin
g
the compressor pressure
ratio
from 6 to 9 in steps of one and the combustion chamber maximum
temperature
from 1
1
00K to 1
4
00K in steps of 100K. The SNT is to be calculated by
dividing
the
net thrust by the mass
airflow
rate.
Plot SFC .vs. S
NT
for these con
ditions using Excel or similar, producing a graph
similar to that
on the first page
.
[30%]
(ii)
Carry out a hand calculation for one of the conditions of the
above;
assume the
compressor and turbine
efficiencies
are isentropic.
Compare
your results of SFC and
SNT to the results produced by the
computer
program
. Explain the difference.
[30%]
(iii)
For three compressor pressure ratios and three combustion temperatures, vary the
Mach number
(at least three Mach numbers, one supersonic)
and altitude
(at least
three alti
tudes, one above 11km),
and plot the variation of SFC and SNT with the
Mach number and altitude
[20%]
(iv)
Discuss the effects of the variation of SFC and SNT with the Mach number and
altitude.
[20%]
You are required to produce only a brief report that answe
rs the questions set above. No
need for introduction or table of contents.
Include references in your report if needed.
rs the questions set above. No
need for introduction or table of contents.
Include references in your report if needed.
FOR MORE INFORMATION ON THIS TOPIC CLICK HERE
MANUFACTURING PROJECT/AIRCRAFT DEVELOPMENT PROJECT
MANUFACTURING PROJECT/AIRCRAFT DEVELOPMENT PROJECT
Project description
(a) Show the dependencies of the activities by completing the Predecessors column of Table 1.<br />
(b) Draw an activity-on-arrow (AoA) network diagram for the project, using node numberings 5, 10, 15, 20, etc.<br />
(c) Using the AoA diagram, carry out a critical path analysis and determine:<br />
• the earliest and latest event times,<br />
• the activity schedule times (earliest and latest starting times, earliest and latest finishing times, and total float) for each activity<br />
• the critical path and project completion time.<br />
(c) Using Excel, draw a Gannt chart for the project. Show the float for each activity and the critical path on the chart.<br />
(d) Discuss how the project manager would use the activity floats in controlling the execution of the project.<br />
(e) Draw the resource chart assuming that each activity requires one team, and carry out resource levelling as much as possible.
(a) Show the dependencies of the activities by completing the Predecessors column of Table 1.<br />
(b) Draw an activity-on-arrow (AoA) network diagram for the project, using node numberings 5, 10, 15, 20, etc.<br />
(c) Using the AoA diagram, carry out a critical path analysis and determine:<br />
• the earliest and latest event times,<br />
• the activity schedule times (earliest and latest starting times, earliest and latest finishing times, and total float) for each activity<br />
• the critical path and project completion time.<br />
(c) Using Excel, draw a Gannt chart for the project. Show the float for each activity and the critical path on the chart.<br />
(d) Discuss how the project manager would use the activity floats in controlling the execution of the project.<br />
(e) Draw the resource chart assuming that each activity requires one team, and carry out resource levelling as much as possible.
FOR MORE INFORMATION ON THIS TOPIC CLICK HERE
American history
American history
Assignment, History
Andrew Jackson was a polarizing and complex figure in American history. Which of the following best represents your view of Jackson? a. He was one of our greatest presidents and is worthy of gracing the $20 bill b. He was the tyrant that the Whigs accused
Andrew Jackson was a polarizing and complex figure in American history. Which of the following best represents your view of Jackson? a. He was one of our greatest presidents and is worthy of gracing the $20 bill b. He was the tyrant that the Whigs accused
Project description
Andrew Jackson was a polarizing and complex figure in American history. Which of the following best represents your view of Jackson? Be sure to back up your argument with specific examples from the historical record.
a. He was one of our greatest presidents and is worthy of gracing the $20 bill
b. He was the tyrant that the Whigs accused him of being
c. Like most presidents he was neither a saint nor a devil – I believe Jackson was a good president with faults.
d. While not the tyrant the Whigs made him out to be, I believe that Jackson’s policies were generally more bad than good for the country
(provide evidence and HISTORICAL ACCURACY, CLARITY, AND LOGIC)
Your paper should begin with an Introduction which sets the prompt in the historical context, the LAST sentence of the intro paragraph is the thesis statement which lists the (minimum of) three points (X,Y,Z) that will be more fully developed in the paper. The first paragraph of the body (paragraph 2) would discuss key point X (this paragraph would have its own thesis as the first sentence, followed by three pieces of evidence/analysis in support), then a paragraph on Y, and finally one on Z. It should ends with a conclusion paragraph – which sums up the argument you made and ties X, Y, and Z together.
Andrew Jackson was a polarizing and complex figure in American history. Which of the following best represents your view of Jackson? Be sure to back up your argument with specific examples from the historical record.
a. He was one of our greatest presidents and is worthy of gracing the $20 bill
b. He was the tyrant that the Whigs accused him of being
c. Like most presidents he was neither a saint nor a devil – I believe Jackson was a good president with faults.
d. While not the tyrant the Whigs made him out to be, I believe that Jackson’s policies were generally more bad than good for the country
(provide evidence and HISTORICAL ACCURACY, CLARITY, AND LOGIC)
Your paper should begin with an Introduction which sets the prompt in the historical context, the LAST sentence of the intro paragraph is the thesis statement which lists the (minimum of) three points (X,Y,Z) that will be more fully developed in the paper. The first paragraph of the body (paragraph 2) would discuss key point X (this paragraph would have its own thesis as the first sentence, followed by three pieces of evidence/analysis in support), then a paragraph on Y, and finally one on Z. It should ends with a conclusion paragraph – which sums up the argument you made and ties X, Y, and Z together.
FOR MORE INFORMATION ON THIS TOPIC CLICK HERE
Visual Arts and Film Studies
Visual Arts and Film Studies
Discuss the representation of social and/or sexual differences in any one or two films by Bergman.
Project description
I chose as a Movie Summer with Monica, But I am open to any other suggestion if you know another movie of Ingmar Bergman. I would like to focus of the social differences, I know this a vast subject but I can touch of the different aspect of the subject but keep in mind that I need the essay:
Focuses on and develops an interesting topic; presents a particularly thoughtful or even original perspective
Has a coherent and convincing argument
Adopts an effective strategy appropriate to the subject at hand, such as a comparison, a controversial interpretation, a rebuttal, etc.
Has an effective introduction and conclusion
Gives specific examples to support the argument
Consists of focused paragraphs linked together with graceful and effective transitions
Is well edited with no or very few typos, grammar mistakes, wordiness, or word usage problems
Has a title
I chose as a Movie Summer with Monica, But I am open to any other suggestion if you know another movie of Ingmar Bergman. I would like to focus of the social differences, I know this a vast subject but I can touch of the different aspect of the subject but keep in mind that I need the essay:
Focuses on and develops an interesting topic; presents a particularly thoughtful or even original perspective
Has a coherent and convincing argument
Adopts an effective strategy appropriate to the subject at hand, such as a comparison, a controversial interpretation, a rebuttal, etc.
Has an effective introduction and conclusion
Gives specific examples to support the argument
Consists of focused paragraphs linked together with graceful and effective transitions
Is well edited with no or very few typos, grammar mistakes, wordiness, or word usage problems
Has a title
FOR MORE INFORMATION ON THIS TOPIC CLICK HERE
Computer sciences and Information technology
Computer sciences and Information technology
Tourist guide systemer
Project description
Task is to write answers for the questions in attached file.
Instruction files
Task is to write answers for the questions in attached file.
Instruction files
question.docx(18,45 KiB)
Perhaps the ‘canonical’ application associated with Mobile HCI is that of the Mobile City Guide Application. One of the seminal research projects in this area was the Lancaster GUIDE project. Describe in detail the original Lancaster Tourist GUIDE system. Your answer should include:
i) a description of the functionality supported by the system,
ii) a description of the approach adopted for storing and retrieving content relating to landmarks within the city
iii) a description of the approach of the approach adopted for obtaining the visitor’s location.
iv) your opinion of the advantages and disadvantages of the chosen approaches.
[10 marks]
Perhaps the ‘canonical’ application associated with Mobile HCI is that of the Mobile City Guide Application. One of the seminal research projects in this area was the Lancaster GUIDE project. Describe in detail the original Lancaster Tourist GUIDE system. Your answer should include:
i) a description of the functionality supported by the system,
ii) a description of the approach adopted for storing and retrieving content relating to landmarks within the city
iii) a description of the approach of the approach adopted for obtaining the visitor’s location.
iv) your opinion of the advantages and disadvantages of the chosen approaches.
[10 marks]
Two different approaches to information delivery were explored through the GUIDE system, namely pull-based and push-based. Explain in detail the differences between the two approaches and how they were implemented and evaluated during the GUIDE project. Also summarise the findings of the user evaluation. If you were asked by a company to evaluation a push based mobile GUIDE system designed for a modern smartphone describe in detail (with full justification) how you would design and carry out such a study.
[10 marks]
[10 marks]
In terms of supporting a user’s navigation task within the city, the Lancaster GUIDE system would provide the user with very direct ‘turn-by-turn’ navigation instructions, e.g. “turn left at the castle entrance”. What would be an alternative approach to providing such direct navigation and under what circumstances do you think such an approach would be appropriate or inappropriate
[2 marks]
[2 marks]
Consider the city of the future – one that is likely to feature an infrastructure of interactive and non-interactive public displays. How might the existence of such displays work in tandem with a user’s personal mobile device in order to support his/her navigation task? You should include in your answer reference to Rukzio’s ‘rotating compass’.
[3 marks]
[3 marks]
FOR MORE INFORMATION ON THIS TOPIC CLICK HERE
Profitability, Long Term Debt, Retained Earnings, Statement of Cash
Profitability, Long Term Debt, Retained Earnings, Statement of Cash Flows, and Conclusion
Project description
The paper should include a cover page, the body of the paper, and a page for references. The paper is not a management report or a history of your company. It is an analysis of the financial statements of your company. The body of the paper should include an introductory paragraph and five Level 1 headings titled Profitability, Long Term Debt, Retained Earnings, Statement of Cash Flows, and Conclusion. The information included in the headings should be on topics from our class discussions and textbook chapter titles.
Introductory paragraph should include the following:
1.)A brief comment about your company.
2.)The state in which the company is incorporated.
3.)The location of the corporate headquarters.
3.)The name of the accounting firm that audited the financial statements.
4.)The date of the financial statements. (The date that the report was filed and the date of the financial statements are not the same.)
1.)A brief comment about your company.
2.)The state in which the company is incorporated.
3.)The location of the corporate headquarters.
3.)The name of the accounting firm that audited the financial statements.
4.)The date of the financial statements. (The date that the report was filed and the date of the financial statements are not the same.)
Profitability should include the following:
1.)A statement on the profitability of the company. Do not copy and paste. Use your own words.
2.)Calculate and interpret the horizontal analysis of the sales.(Chapter 18 )
3.)Calculate and interpret the vertical analysis, profit margin ratio. (Chapter 18)
4.)Calculate and interpret the gross profit ratio. (Chapter 18)
1.)A statement on the profitability of the company. Do not copy and paste. Use your own words.
2.)Calculate and interpret the horizontal analysis of the sales.(Chapter 18 )
3.)Calculate and interpret the vertical analysis, profit margin ratio. (Chapter 18)
4.)Calculate and interpret the gross profit ratio. (Chapter 18)
Long term debt should include the following:
1.)How much long term debt does your company have?
2.)What type of long term debt does your company have?
3.)Did it increase or decrease from the prior period?
4.)What caused it to increase or decrease?
5.)Calculate and interpret the current ratio.
6.)Calculate and interpret the debt to total assets ratio.
1.)How much long term debt does your company have?
2.)What type of long term debt does your company have?
3.)Did it increase or decrease from the prior period?
4.)What caused it to increase or decrease?
5.)Calculate and interpret the current ratio.
6.)Calculate and interpret the debt to total assets ratio.
Retained earnings should include the following:
1.)What was the beginning retained earnings balance.
2.)What caused retained earnings to increase?
3.)What caused retained earnings to decrease?
4.)Were dividends paid?
5.)What is the ending retained earnings balance.
1.)What was the beginning retained earnings balance.
2.)What caused retained earnings to increase?
3.)What caused retained earnings to decrease?
4.)Were dividends paid?
5.)What is the ending retained earnings balance.
Statement of Cash Flows should include:
1.)The ending cash balance.
2.)Did the cash balance increase or decrease from the previous period?
3.)What caused the cash balance to increase or what caused the cash balance to decrease?
4.)Why is the Statement of Cash Flows important to investors?
5.)How is your company managing their cash?
1.)The ending cash balance.
2.)Did the cash balance increase or decrease from the previous period?
3.)What caused the cash balance to increase or what caused the cash balance to decrease?
4.)Why is the Statement of Cash Flows important to investors?
5.)How is your company managing their cash?
Conclusion: This report is a financial analysis of the company. It is not a history report. Based on the information you have learned in ACCT 221 and your analysis of the SEC 10-K, what are your comments about the company.
FOR MORE INFORMATION ON THIS TOPIC CLICK HERE
Subscribe to:
Posts (Atom)