Category Archives: Engineering

Design of Power system for a Data Center_http://customwritings-us.com/orders.php


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Design of Power system for a Data Center

A data center with the dimension of 40ft Long x 30ft Wide x12ft High is located on the 12th floor of a high rise building in downtown Chicago, IL.   The data center must operate all the time regardless of the availability of power from the utility. The loads can be categorized as high, medium and low critical. Table 1 shows the power rating of each cabinet and the critical level of each load.  The cabinets are 12-ft wide x 6-ft High x 2-ft deep. Four of these cabinets must be strategically placed in the room to obtain the best heat exchange at minimum cost. The cooling registers are located on the floor and the exhaust registers are placed on the ceiling as shown in Figure 1. The cooling cost per BTU is $0.01. Each cabinet generates 30,000 BTU per hour and heat must be removed to operate properly. The cost of electricity is $0.1 per kilowatt-hour. Exhaust fan can help to remove heat faster.  A 1000 cfm require a 1 hp motor.

Each highly critical load must be supported by 5 sources of power; such as one utility, 2 UPS and two generators.

Medium critical loads require utility, UPS and two generators.

Low critical loads require utility, UPS and a generator.

Select the sizes for of the two generators to provide power to the racks as well as cooling for High and Medium Critical loads.

The UPS must be able to withstand 20 minutes for Medium and low and 1 hour for High Critical Loads.

Determine the depth of Discharge and battery sizes and type using Table 2 information.

UPS costs $750.00/Kw for 20 minutes operation.

UPS costs $2500/kW for 1 hour operation.

Generator Costs $1000/KW.

Deliverables:

  1. Provide a drawing to show the location of each load in the cabinet to obtain proper cooling for each load at lowest cost and risk
  2. Provide a drawing for the cabinet layout
  3. Determine the size of cooling system (BTU)
  4. Calculate the size exhaust fans (CFM, hp)
  5. Provide the UPS size
  6. Calculate the Battery size and type in the UPS system
  7. Determine the Generator size
  8. Calculate the Total power requirement (with 20% safety margin)
  9. Determine the System Efficiency
  10. Calculate Total Cost of Cooling, UPS and Generators.

 

Table-1 Load per Cabinet

20 kW High Critical
20 kW High Critical
10 kW Medium Critical
15 kW Medium Critical
30 kW Low Critical
30 kW Low Critical

 

Table-2 Battery Information

 

 

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Figure-1 Data Center Cabinet Layout for Cooling

EAT223 – THERMOFLUIDS AND ENGINES


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Moderated November 2016
University of Sunderland
Faculty of Applied Sciences
Department of Computing, Engineering and Technology
EAT223 – THERMOFLUIDS AND ENGINES
Assignment 1 of 1
The following learning outcomes will be assessed:
Knowledge
Critical knowledge of the fundamental concepts and analytical methods in the solution of a range of problems related to thermodynamics, fluid mechanics, and heat transfer.
Skills
Design and analyse a variety of air standard cycles and vapour power cycles.
Important Information
You are required to submit your work within the bounds of the University Infringement of Assessment Regulations (see your Programme Guide). Plagiarism, paraphrasing and downloading large amounts of information from external sources, will not be tolerated and will be dealt with severely. Although you should make full use of any source material, which would normally be an occasional sentence and/or paragraph (referenced) followed by your own critical analysis/evaluation. You will receive no marks for work that is not your own. Your work may be subject to checks for originality which can include use of an electronic plagiarism detection service.
Where you are asked to submit an individual piece of work, the work must be entirely your own. The safety of your assessments is your responsibility. You must not permit another student access to your work.
Where referencing is required, unless otherwise stated, the Harvard referencing system must be used (see your Programme Guide).
Please ensure that you retain a duplicate of your assignment. We are required to send samples of student work to the external examiners for moderation purposes. It will also safeguard in the unlikely event of your work going astray.
Submission Date and Time
Before 4pm, Wednesday 22nd March 2017
Submission Location
SunSpace Dropbox
Page 2 of 3
Moderated November 2016
This assignment is set out in two parts, where the first part should help you build the second. You will be allocated one from each of a-e, A-E, and 1-4 (as defined below) to ensure you have an individual set of data for the assignment.
PART 1: IDEAL STANDARD RANKINE CYCLE (50% of marks)
You are required to analyse a standard Rankine cycle by both hand calculation and using the simulation package CyclePad, in order to validate the software. The cycle specifications are as follows:
 Boiler pressure: (a) 40; (b) 45; (c) 50; (d) 55 bar; (e) 60 bar (as assigned).
 Boiler output temperature: (A) 450; (B) 500; (C) 525; (D) 550C; (E) 575C (as assigned).
 Condenser pressure: (1) 0.6; (2) 0.65; (3) 0.7; (4) 0.75 bar (as assigned).
Assume the mass flow rate is 1 kg/s, so that derived work and heat quantities are specific (i.e. per kg of steam). Use a summary table to compare the following:
 The specific enthalpy at each point in the cycle, determined both by hand calculation, and by CyclePad.
 The net work (Wnet).
 The heat in (Qin).
 The thermal efficiency (ηth).
PART 2: REHEAT RANKINE CYCLE (50% of marks)
*** You should perform this analysis using CyclePad only. ***
In order to improve the net work output and efficiency of the plant, you are required to investigate the implementation of a two-stage reheat Rankine cycle (as covered in class). Use the same pressures and temperature assigned in Part 1. However, you must choose a pressure for the second stage i.e. the lower pressure turbine and explain how you chose it.
For your chosen design, use another summary table to compare the quantities listed above, obtained from the CyclePad analysis of the reheat Rankine cycle.
More detailed submission requirements are summarised overleaf.
Hints on using CyclePad
(i) You can download a free copy of CyclePad from the following link. If you have any trouble obtaining it, email me and I will send you a copy.
http://www.qrg.northwestern.edu/software/cyclepad/cyclesof.htm
(ii) You will find a Rankine Cycle Solved in the CyclePad library. Use this to help you get started with the first part of the assignment. It comprises four parts: heater, turbine, cooler and pump, corresponding to the boiler, turbine, condenser and feed pump, respectively.
(iii) Note that both heater and cooler are modelled as isobaric (i.e. constant pressure), and both turbine and pump are modelled as adiabatic and isentropic.
(iv) In the second part, you can use the Reheating Vapor Cycle Solved in the library as a template.
Page 3 of 3
Moderated November 2016
Submission requirements
You should keep the material to the minimum necessary to fulfil the following, in the order indicated.
Stage 1 (50%)
 A summary table, which includes your manually calculated results (as outlined above) and the CyclePad results.
 Detailed cycle hand calculations, including an annotated diagram of the cycle schematic. This can be hand written, but must be neat and legible.
 Screenshots of the CyclePad Cycle Properties window, the Assumptions Made window, and the T-s diagram generated by the software.
Stage 2 (50%)
 A summary table, showing the CyclePad specific enthalpy results for the reheat Rankine cycle.
 An annotated diagram of the cycle schematic.
 Screenshots of the CyclePad Cycle Properties window, the Assumptions Made window, and the T-s diagram generated by the software.
Untidy or illegible work will be penalised.
This assignment is worth 30% of the total module mark.

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Assignment help_IE 424


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Assignment help_IE 424

 

IE 424

Spring 2017

Instructions:  Answer questions 1 through 4. Please show all work.  You must not discuss this exam with your classmates or other people—all work must be your own.  Any research must be properly cited.  This exam is due by 11:59 PM Mountain Time on March 15, 2016.  Your late submittal will lose points starting at 12:01 am on Thursday 3/16 so plan accordingly.

 

 

  1. Valles Global Industries has a division that operates a fishing fleet that fishes for Alaskan cod. In the table entitled “Cod Catch” in the attached file, you will find the history of the fleet’s catches over 24 months.  Develop a forecasting model for the fleet that illustrates the forecast for 24 months plus month 25.  Use a smoothing factor (alpha) of .1.  Show how you calculated each forecast and the forecast error.  Discuss the smoothing factor—will changing this factor improve your forecast?  How?

 

 

  1. The Sohn Aerospace Division of Sohnco has a demand forecast for the first three months of next year is

January         600 ships

February        100 ships

March             900 ships

 

Strangely, they have 100 ships in stock as of December 31.

 

  1. a) Plot cumulative demand and a level aggregate production plan with no back orders and no ending inventory.
  2. b) What production is needed each month to meet part a’s conditions?
  3. c) Suppose any left-over ships at the end of each month cost $500,000 per month in storage and interest costs. Assume the start-up inventory is not part of the calculation.  Should we make any changes to our plan?  Explain your answer.

 

 

  1. Sohn Aerospace is looking at another product line. Their new drone helicopter is popular and they would like to sell what they can with no backorders.  The CEO does not wish to hire and fire people during the year so he wants you hire a constant number of employees and maintain that size workforce.  Review the attached file for the table of data and then answer the following questions:

 

  1.  What daily production rate and number of employees will be necessary?
  2. How many units will be in inventory at the end of each quarter?

 

  1. Mullen Magic Shows is evaluating attendance at the shows and planning whether to train more magicians.  They have the following data:

 

Year                Total Audience

 

2013               97130

2014               101326

2015               96956

2016               99816

2017               99694

2018               103762

2019               104958

2020               110988

2021               112157

2022               110370

 

  1. Plot these data, develop a hypothesis of an appropriate model, estimate the model’s parameters, and forecast passengers for 2023-2025.
  2. Illustrate an exponential smoothing model using an alpha of .1 and then an alpha of .5.
  3. In doing some analysis, they assume each show has about 500 attendees.  Each magician they hire can work up to 50 shows a year and is paid $1500 per show up to 50 shows.  Recently, magicians complained that they are under contract for 50 shows but only paid for shows they work.  If each magician is paid $500 per show she/he does not work, what does this policy cost per year?

 

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EAT223 – THERMOFLUIDS AND ENGINES


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University of Sunderland

Faculty of Applied Sciences

Department of Computing, Engineering and Technology

EAT223 – THERMOFLUIDS AND ENGINES

Assignment 1 of 1

The following learning outcomes will be assessed:

Knowledge

Critical knowledge of the fundamental concepts and analytical methods in the solution of a range of problems related to thermodynamics, fluid mechanics, and heat transfer.

Skills

Design and analyse a variety of air standard cycles and vapour power cycles.

 

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Important Information

You are required to submit your work within the bounds of the University Infringement of Assessment Regulations (see your Programme Guide). Plagiarism, paraphrasing and downloading large amounts of information from external sources, will not be tolerated and will be dealt with severely. Although you should make full use of any source material, which would normally be an occasional sentence and/or paragraph (referenced) followed by your own critical analysis/evaluation. You will receive no marks for work that is not your own. Your work may be subject to checks for originality which can include use of an electronic plagiarism detection service.

Where you are asked to submit an individual piece of work, the work must be entirely your own. The safety of your assessments is your responsibility. You must not permit another student access to your work.

Where referencing is required, unless otherwise stated, the Harvard referencing system must be used (see your Programme Guide).

Please ensure that you retain a duplicate of your assignment. We are required to send samples of student work to the external examiners for moderation purposes. It will also safeguard in the unlikely event of your work going astray. Submission Date and Time Before 4pm, Wednesday 22nd March 2017
Submission Location SunSpace Dropbox

 

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Assignment help-EAT216 – COMPUTER AIDED ENGINEERING


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Moderated October 2016
University of Sunderland
Faculty of Applied Sciences
Department of Computing, Engineering and Technology
EAT216 – COMPUTER AIDED ENGINEERING
Assignment 3 of 3, 2016 – 2017
The following learning outcomes will be assessed:
Knowledge
An understanding of the use of commercial mathematical software packages to assist in solving engineering problems.
Skills
the ability to develop and analyse mathematical models of the behaviour
of a component or system due to external influences and so predict the performance of that component or system.
Important Information
You are required to submit your work within the bounds of the University Infringement of Assessment Regulations (see your Programme Guide). Plagiarism, paraphrasing and downloading large amounts of information from external sources, will not be tolerated and will be dealt with severely. Although you should make full use of any source material, which would normally be an occasional sentence and/or paragraph (referenced) followed by your own critical analysis/evaluation. You will receive no marks for work that is not your own. Your work may be subject to checks for originality which can include use of an electronic plagiarism detection service.
Where you are asked to submit an individual piece of work, the work must be entirely your own. The safety of your assessments is your responsibility. You must not permit another student access to your work.
Where referencing is required, unless otherwise stated, the Harvard referencing system must be used (see your Programme Guide).
Please ensure that you retain a duplicate of your assignment. We are required to send samples of student work to the external examiners for moderation purposes. It will also safeguard in the unlikely event of your work going astray.
Submission Date and Time
Before 4pm, Wednesday 15th March 2017
Submission Location
SunSpace Dropbox
Page 2 of 4
Moderated October 2016
Part 1: Drag coefficient for flow around a sphere
Using the tutorial provided concerning air flow around a sphere as a basis, you are required to
validate the SolidWorks flow simulation software. To do this, derive the drag coefficient CD at the
following Reynolds numbers: 1 10, 100, 10,000, and 100,000.
You will be required to compare your values with those shown in Fig. 1 (final page). To do this you
may use Fig. 1 and superimpose your values, plotted by hand. You should submit this as part of
your report.
Part 2: Flow over a cone
Develop a flow simulation for a three dimensional cone pointed into the airflow, as represented by
Fig. 2. You should create a three dimensional cone with the value of the half-vertex angle (ε)
assigned to you. This is the angle measured from the centreline of the cone to one of its walls, also
shown in Fig. 2. You should also derive the value of the drag coefficient CD, for a Reynolds number
anywhere in the range 105 and 106.
Fig. 2: Cone
Note that for both the sphere and the cone, Reynolds number is given by the following equation,
where D is the diameter of the sphere, or the base of the cone as shown in Fig. 2:

UD
Re 
You can assume the density and dynamic viscosity of air when using this equation are 1.177 kg/m3
and 1.84610-5 Pa s, respectively.
ε D
Page 3 of 4
Moderated October 2016
Report
Your report should include the following information:
Description
Mark
Part 1
Demonstration of working simulation of flow over a sphere (in class).
10
Derivation of drag coefficient CD at the required values of the Reynolds number (report).
20
Plot of CD versus Re (report).
10
Part 2
Demonstration of working simulation of flow over a cone (in class).
10
A description of how the problem was tackled in SolidWorks. This should include any assumptions made and a tabulated summary of the boundary conditions used. It should also include screenshots of the model and mesh, and vector and contour plots of the resulting flow (report).
30
Derivation of drag coefficient CD, for a Reynolds number between 105 and 106 (the value you have used must be stated).
20
Marks will be deducted for untidy or illegible work.
Reference
Hoerner, S. F., 1965. Fluid-Dynamic Drag. 1st ed. Bricktown New Jersey: Hoerner Fluid Dynamics
K. Burn
October 2016
Page 4 of 4
Moderated October 2016
Fig. 1: CD versus Reynolds number for flow across a sphere (Aerospaceweb.org, 2012)

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CHEG 3300 – Mass Transfer-Mechanistic Engineering Approach to Improve Mass Transfer in Unit Operations


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Project Work (CHEG 3300 – Mass Transfer)
Mechanistic Engineering Approach to Improve
Mass Transfer in Unit Operations
Submission due dates: March 13 and April 21
Project Description
A chemical engineer has a task to enhance the hydrodynamic and mass transfer rate in the fluid by
developing a mechanistic engineering approach to vary the physical properties of the fluid,
intensify the absorption and diffusion process. One of the approaches could be incorporating
nanofluids or nanoparticles to enhance the performance of gas absorption systems. The principal
advantages of using nanoscopic fluids or nanoparticles are: (a) amount of chemical absorbents can
be decreased (b) tower or column height can be reduced, both by achieving larger mass transfer
coefficients with nanoscopic fluids or particles. The major objective of this project work is to
propose a comprehensive mass transfer model to enhance the mass transfer rate either in a packed
bed column or a plate column.
Investigate how to enhance the gas side mass transfer coefficient. Thoroughly investigate various
operating conditions by specifying the characteristic parameters of the system in the first step.
Consider a laminar flow for both the compressible gas and incompressible fluid. The effects of
pressure and concentration on the physical properties of the gas phase must be studied. It is
important in the first step to achieve the equilibrium state for the interacting components.
Investigate the transport properties such as molecular diffusion to achieve the state. Thoroughly
study the thermodynamics in the solution and how to accomplish the equilibrium steady states by
sequentially investigating the properties of the system, variables, parameters to be evaluated and
their corresponding boundary conditions to understand the contributions, limitations of latent heat
and sensible heat combined with hydrodynamic properties to maintain the equilibrium throughout
the column height.
Mass transfer coefficients can be influenced by the forces acting on the Brownian motions of the
nanoparticles. The direction of flow must be towards the interface. Your approach should be
directed towards increasing the mass transfer coefficients in the column resulting in larger
diffusion flux of the gas into the liquid phase. Consider the residence time distribution in the
column. For example, an increase in the gas flow rate reduces the residence time. Mass transfer
rate can be enhanced because of the large reaction rate. Facilitating larger liquid velocity closer to
the gas-liquid interface is another phenomenon that can enhance the mass transfer rate. Overall,
liquid flow rate plays an important role in the column performance.
Natural convection heat transfer of nanofluids can be considered. You should study the
advantages of using nanofluids compared to conventional micro fluids and how the volume
fraction of nanofluids has an advantage over the micro fluids. Study the heat conductivity
coefficient, enthalpy changes that limit the enhancement heat transfer of nano and micro fluids.
For example when compared to water, nanofluids deteriorate the convection heat transfer
(determined by the volume fraction). Also please note that the heat conductivity coefficient cannot
compensate for the increasing viscosity of the nanofluid. A continuity equation combined with
momentum equation (relating the above behavior) can be evaluated in terms of thermal
conductivity, specific heat and temperature of mixed nanofluid. Enhancement heat transfer can be
accomplished at high temperature differences. The driving force initially is derived from the
temperature difference. Adding nanoparticles not only increases the heat conductivity but also
increases the viscosity of the fluid which creates the viscous forces for the natural convection heat
transfer. At low temperatures, viscous forces play a major role for heat conduction. Therefore the
heat transfer performances at lower temperatures will be worse than the higher temperatures. You
also need to study on how to increase the collisions between these nanoparticles to increase
convection heat and mass transfer. Please note: (a) driving forces increase with temperature
difference (b) dynamic equilibrium in an equilibrium process can be at steady state, but a steady
state need not be in equilibrium in the irreversible process.
Assumptions: Assume that the mixed nanofluid is a continuous medium. There is no motion slip
between nanoparticles and fluids. But there should be thermal equilibrium between nanoparticles
and the mixed fluid. Neglect the effects of column shape, type of material and any presence of
rotating magnetic fields. Assume that the liquid phase composed of nanofluids is a homogeneous
continuous medium. Use fluid mechanics and hydraulic concepts to explain the hydrodynamic
behavior of the column. The liquid and gas flow counter currently in the column. The same
approach can be generalized for the entire column. In its standard state, the enthalpy change of
formation of any element has to be zero. (Note: Enthalpy is proportional to temperature change
or temperature gradient, only in an adiabatic process. An isothermal process will have enthalpy
change). The system has to be in dynamic equilibrium to achieve steady state.
Propose a continuity equation which captures the above phenomena mentioned for an
incompressible liquid phase and a compressible gas phase.
1. Assuming laminar flow, propose an equation of motion for the gas phase.
2. What can be the species continuity equations for liquid and gas phases in the column (nonconductive
systems)?
3. How do we derive the driving force for the overall mass diffusion flux? Use Fick’s law
combined with flow factors of the fluid.
4. Propose a gas phase and a liquid phase mass transfer model which explains the overall
phenomenon at the interface.
Target Assessment Dates:
A. By Monday, March 13, submit the outline/proposal (3-4 pages) for 50% grade:
 A conceptual model of the proposed system …………….. (15 points).
 Proposed approach defining ……………….(20 points)
o variables
o parameters and
o boundaries or limitations
 Conditions leading to interfacial thermal equilibrium (steady state) ….(15 points)
B. By Friday, April 21, submit the following full project report (8-10 pages including the
previous proposal of March 13) for 50% grade:
 Questions 1-4 mentioned above.
Project Write-Up Structure (valid only for the final report of April 21):
• Problem Statement ………………………………………………..(5 points)
• Task Identified (Include the proposal outline of Mar 13 here)….(5 points)
• Parameters Selected …………………………………………………(5 points)
• Background ……….…………………………………………………(5 points)
• Approach …………………………………………………………..(10 points)
• Description …………………………………………………………(10 points)
• Conclusion ……….…………………………………………………(5 points)
• References ……………………………………………………………(5 points)

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Need help-Heron’s Fountain


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1 Mark every piece of work with your name (all names in the group for group work), module title and your tutor’s name.

2 If your work has more than one part ensure that all parts are secured together.

3 Complete all details in the table below.

4 Attach the form securely to your assignment before you submit it.

5 Late submission of a piece of assessed coursework will be penalised by 10% if submitted no more than 24 hours after the published deadline. Once the deadline has been exceeded by 24 hours it will not be accepted without evidence of mitigating circumstances (see student handbook).

Programme   Group:  A    B    C    D    E

1     2    3    4     5   (Please circle)

6     7    8    9     10

    Module Title:
Known as:

(If applicable)

  UoL Number:
Date due:  

 

Date submitted:
Module Tutor:

 

 

  Assignment Title:

 

Comments

 

 

 

 

 

 

 

 

 

 

 

 

 

Mark

 

 

The mark shown is provisional only and subject to confirmation by the Module Assessment Board.

I confirm that this work is submitted in accordance with the University of Lincoln ISC regulations.  I fully understand that penalties may be incurred if any of the rules and regulations are infringed.

In addition I confirm that this is all my own work. If group work, separate declarations are required.

Signed:                                                                                                                                 Date:

 

Practical Assignment: Fluid mechanics, 2014.

Heron’s fountain

.

[http://arxiv.org/ftp/physics/papers/0310/0310039.pdf]

Often called the magic fountain, Herons Fountain may look like an example of perpetual motion machine;

Your task is to explain how the water ends up at a higher height than it begins.

How the marks will be awarded:

8 marks will be awarded for this task.

  1. Who was the person who first came up with the device which appeared to raise water to a greater height without any energy input? [2marks]
  2. Labelled diagram Which fully explains how a ‘Herons Fountain works [4marks]
  3. Worked example predicting the height increase with known fluid/pipe diameters [2marks]

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Engineering Assignment help


Engineering Assignment help

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Help write-Lab #6, Stimulus Control: Attention


Help write-Lab #6, Stimulus Control: Attention

Lab #6             Stimulus Control: Attention

Cover page                       

Introduction

 Introduces concept threads.

Please note the experiment is based on a methodology of identifying configural cues, elements, and stimulus and contextual dimensions.  By then, presenting specific stimuli with single or multiple elements we are able to infer attention.  A reference that uses this methodology will be a good tread to weave the last lab report.

 

Method

Participant

Apparatus

 Procedure

*There were (15) stimuli in the pretest and 17 in the post test due to the addition of the SD and the S Δ in the second elements test.

 Results

Relevant data to be highlighted is based on concept threads and discussion.

  1. Responding during the first elements test

Figure-Ground

Color (wavelength)

Interactions

Responding during the discrimination training.

Rate between and within multiple schedules of SD and SΔ

 

  1. Responding during the second (post-training) elements test

Figure-Ground

Color (wavelength)

            Interactions

 

Discussion

Discuss

Excitation & Inhibition

Figure-Ground

Color (wavelength)

Interactions

Other, dimensions, elements, e.g. brightness or Gestalt

 

Threads woven together.

Close

 

References : ONLY ONE ARTICLE CAN BE USED.

Figure Captions

Figures

 

Format F Procedure D Results C Data concepts B

Treads that weaves report together B A. Whole report in APA format.

 

Need help-Wind Turbine Investigation


Need help-Wind Turbine Investigation

The following experiment enables you to:

  • Measure the energy in the wind.
  • Assess a commercially available wind turbine in an environmental wind tunnel.
  • Determine the power curve of a wind turbine and obtain cut-in speeds
  • Calculate the coefficient of performance of a turbine
  • Calculate the Solidity and Tip-speed ratio.
  • See how the energy is converted stored and utilised.
  • Examine the Beaufort wind scale.

Introduction:

The power available to a wind turbine is the kinetic energy passing per unit time in a column of air with the same cross sectional area A as the wind turbine rotor, travelling with a wind speed U0. Thus the available power is proportional to the cube of the wind speed. See the figure below.

Equipment

The equipment is provided by Marlec and the following information is from their web page but has been modified slightly for this labsheet.

The Rutland 913 is designed for marine use on board coastal and ocean going yachts usually over 10m in length. This unit will generate enough power to serve both domestic and engine batteries on board.
The Rutland 913 is a popular sight in marinas, thousands are in use worldwide, boat owners like it’s clean, aerodynamic lines and its quiet and continuous operation. Without doubt this latest marine model accumulates more energy than any other comparable windcharger available, you’ll always see a Rutland spinning in the lightest of breezes!

  • Low wind speed start up of less than 3m/s
  • Generates 90w @ 37m/s, 24w @ 20 m/s
  • Delivers up to 250w
  • Modern, durable materials for reliability on the high seas
  • SR200 Regulator – Shunt type voltage regulator prevents battery overcharge

Theory:

During this experiment you will make use of the following equations to calculate key parameters

Key formulae

Energy in the wind E = (watts)

Swept area of rotor A=πR2

 

Electrical power output P=VxI (watts)

 

Coefficient of performance

 

Tip speed ratio

 

 

 

Solidity = blade area/swept area

 

R is the rotor radius (m)

ρ is air density say 1.23 kg/m3

Uo is the wind speed (m/s)

V is voltage (volts)

I is current (amps)

ω (rads/sec) is the angular velocity of the rotor found from

 

 where N is the rotor speed in revs/min

 

 

 

Procedure:

 

Step 1         Ensure that everything is setup for you and switch on the tunnel.

Step 2         Adjust the wind speed and let it stabilize

Step 3         Measure the wind speed, voltage and current

Step 4         If available measure the rotor speed with the stroboscope.

Repeat steps 2 – 4 for other wind speeds up to a maximum of 10m/s if achievable.

 

Gather your data by completing tables 1 and 2

 

Wind speed

Uo  (m/s)

Beaufort

number

Effect on land Output voltage

V (volts)

Output current

I (amps)

Rotor speed

N (revs/min)

Table 1 measured data

 

Calculate the following

Rotor radius use a ruler to measure from center to tip of turbine R =
Swept area A=πR2

 

A =
Blade area = blade area + hub area

do your best!

  =
Solidity = blade area / swept area.   =

Table 2 measured data

 

 

 

Now analyse your data by completing table 3.

 

Energy in the wind Electrical power Coefficient of performance Tip speed ratio
E =  (watts) P = V x I

 

(watts)

P/E

(or column 2 /column 1)

Table 3 Analyse your data

 

Present your data:

Now present your results in graphical format to give you a better understanding of the data you have gathered and analysed.

 

Use excel and the x-y scatter chart for this.

 

Graph 1

Plot the values Uo (x-axis) against P (y1-axis) and E (y2-axis).

 

Graph 2

Plot the values of Uo (x-axis) against Cp (y-axis).

 

What conclusions do you draw?

 

How efficiently are you converting the kinetic energy in the wind into electrical energy that is stored chemically in the batteries?

 

Write up the laboratory formally and submit to turnitin. Please ensure presentation is clear and quote fully any references.


 

The Beaufort Wind Speed Scale

Beaufort
Number
Wind Speed at 10m height Description Wind Turbine
effects
Effect on
land
Effect at
Sea
  m/s          
0 0.0 -0.4 Calm None Smoke rises vertically Mirror smooth
1 0.4 -1.8 Light None Smoke drifts; vanes unaffected small ripples
2 1.8 -3.6 Light None Leaves move slightly Definite waves
3 3.6 -5.8 Light Small turbines start – e.g. for pumping Leaves in motion; Flags extend Occasional breaking crest
4 5.8 -8.5 Moderate Start up for electrical generation Small branches move Larger waves; White crests common
5 8.5 -11.0 Fresh Useful power Generation at 1/3 capacity Small trees sway Extensive white crests
6 11.0 -14.0 Strong Rated power range Large branches move Larger waves; foaming crests
7 14.0 -17.0 Strong Full capacity Trees in motion Foam breaks from crests
8 17.0 -21.0 Gale Shut down initiated Walking difficult Blown foam
9 21.0 -25.0 Gale All machines shut down Slight structural damage Extensive blown foam
10 25.0 -29.0 Strong gale Design criteria against damage Trees uprooted; much structural damage Large waves with long breaking crests
11 29.0 -34.0 Strong gale Widespread damage
12 >34.0 Hurricane Serious damage Disaster conditions Ships hidden in wave troughs

Supplementary Theory

The power available to a wind turbine is the kinetic energy passing per unit time in a column of air with the same cross sectional area A as the wind turbine rotor, travelling with a wind speed u0. Thus the available power is proportional to the cube of the wind speed.

We can see that the power achieved is highly dependent on the wind speed. Doubling the wind speed increases the power eightfold but doubling the turbine area only doubles the power. Thus optimising the siting of wind turbines in the highest wind speed areas has significant benefit and is critical for the best economic performance. Information on power production independently of the turbine characteristics is normally expressed as a flux, i.e. power per unit area or power density in W/m2. Thus assuming a standard atmosphere with density at 1.225kg/s :

Wind speed m/s     Power W/m squared               5.0                76.6              10.0               612.5              15.0              2067.2              20.0              4900.0              25.0              9570.3

The density of the air will also have an effect on the total power available. The air is generally less dense in warmer climates and also decreases with height. The air density can range from around 0.9 kg/m3 to 1.4kg/m3. This effect is very small in comparison to the variation of wind speed.

 

In practice all of the kinetic energy in the wind cannot be converted to shaft power since the air must be able to flow away from the rotor area. The Betz criterion, derived using the principles of conservation of momentum and conservation of energy gives a maximum possible turbine efficiency, or power coefficient, of 59%. In practise power coefficients of 20 – 30 % are common. The section on Aerodynamics discusses these matters in detail.

 

Most wind turbines are designed to generate maximum power at a fixed wind speed. This is known as Rated Power and the wind speed at which it is achieved the Rated Wind Speed. The rated wind speed chosen to fit the local site wind regime, and is often about 1.5 times the site mean wind speed.

The power produced by the wind turbine increases from zero, below the cut in wind speed, (usually around 5m/s but again varies with site) to the maximum at the rated wind speed. Above the rated wind speed the wind turbine continues to produce the same rated power but at lower efficiency until shut down is initiated if the wind speed becomes dangerously high, i.e. above 25 to 30m/s (gale force). This is the cut out wind speed. The exact specifications for designing the energy capture of a turbine depend on the distribution of wind speed over the year at the site.

 

Performance calculations

 

Power coefficient Cp is the ratio of the power extracted by the rotor to the power available in the wind.

It can be shown that the maximum possible value of the power coefficient is 0.593 which is referred to as the Betz limit.

where

Pe is the extracted power by the rotor (W)

V¥ is the free stream wind velocity (m/s)

A is area normal to wind         (m2)

ρ is density of the air              (kg/m3)

 

 

The tip speed ratio (l) is the ratio of the speed of the blade tip to the free stream wind speed.

 

 

where

w is the angular velocity of the rotor (rads/sec), and

R is the tip radius (m)

 

This relation holds for the horizontal axis machine which is the focus of these notes.

 

The solidity (g) is the ratio of the blade area to the swept frontal area (face area) of the machine

 

Blade area = number of blades * mean chord length * radius = N.c.R

 

Mean chord length is the average width of the blade facing the wind.

 

Swept frontal area is pR2

 

 Need help-Wind Turbine Investigation

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

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