Tuesday Cuddly Wombats Ellis Report2

download Tuesday Cuddly Wombats Ellis Report2

of 35

Transcript of Tuesday Cuddly Wombats Ellis Report2

  • 8/8/2019 Tuesday Cuddly Wombats Ellis Report2

    1/39

    Effect of aspect ratio, initial temperature, and air

    speed on the heat transfer coefficient of a hanging

    vertical plate

    Submitted by:

    Cuddly Wombats

    Team Members:

    Eric EllisRobert Martin

    Tom McCrocklin

    Jose Villanueva

    Team Leader:

    Tom McCrocklin

    Instructor:

    Josh Strodtbeck, [email protected]

    Dr. Mohamed Hassan Ali, [email protected]

    University of Kentucky

  • 8/8/2019 Tuesday Cuddly Wombats Ellis Report2

    2/39

    Dept. of Mechanical Engineering

    ME 311-002 Experimentation II

    Experiment Conducted on:

    February 23, 2010

    Report Submitted on:

    March 9, 2010

  • 8/8/2019 Tuesday Cuddly Wombats Ellis Report2

    3/39

    Table of Contents

    Nomenclatures

    7

    1. Abstract8

    2. Background &

    Theory

    8

    3. Experimental

    Arrangement

    12

    3.1 Facilities...

    ................................12

    3.2 Diagnostics and Sensor

    Calibration........................13

    3.2.1 Small Plate

    Thermocouple/DMM

    14

    3.2.2 Large Plate

    Thermocouple/DMM

    14

    3.2.3 Air Flow

    Rate

    ..14

    3.3 Experimental Set-

    up.............................

    .14

    3.4 Experimental

    Procedure

    ..16

    3

  • 8/8/2019 Tuesday Cuddly Wombats Ellis Report2

    4/39

    1. Results and

    Analysis

    .16

    5.1Test

    Matrix..........

    ........................16

    5.2 Experimental

    Calculations

    ..18

    5.3 Response

    Plots...................

    ..............20

    5.4 Regression Model and

    Residuals........................22

    5.5 Contour

    Plots................

    ................23

    1. Discussion and

    Conclusions

    ..24

    2. References

    27

    3. Appendices

    28

    8.1 Appendix A: Thermocouple/DMM

    Calibrations.28

    8.2 Appendix B: Converting Response

    Values.30

    8.3 Appendix C: Decision Limit and Effect Calculations..

    .32

    4

  • 8/8/2019 Tuesday Cuddly Wombats Ellis Report2

    5/39

    8.4 Appendix D: Response Plot Calculations...

    .33

    8.5 Appendix E: Residual Model

    Calculations34

    8.6 Appendix F: Contour Plot

    Calculations..35

    5

  • 8/8/2019 Tuesday Cuddly Wombats Ellis Report2

    6/39

    List of Tables

    Table 1: List of Equipment and Serial

    Numbers.12Table 2: Experimental

    Factors.

    17

    Table 3: Test matrix with the eight treatments

    defined..17

    Table 4: Test matrix with heat transfer coefficients, averages, and

    variance..19

    Table 5: Temperatures for large plate thermocouple

    calibration.27

    Table 6: Temperatures for small plate thermocouple

    calibration.28

    Table 7: Heat Transfer Coefficient

    Calculations30

    Table 8: Results of Heat Transfer Coefficient calculations with

    levels..31

    Table 9: Results of Statistical

    Analysis.32

    Table 10: Effect

    Calculations

    ..32

    Table 11: Error

    Calculations

    33

    Table 13: Residual Error

    Calculations..3

    4

    6

  • 8/8/2019 Tuesday Cuddly Wombats Ellis Report2

    7/39

    Table 14: Contour Plot Calculations for Large

    Plate..35

    Table 15: Contour Plot Calculations for Small

    Plate36

    7

  • 8/8/2019 Tuesday Cuddly Wombats Ellis Report2

    8/39

    List of Figures

    Figure 1: Forced Convection (2)...9

    Figure 2: Natural Convection (2)

    ..9

    Fig. 3: Large and Small Aluminum Plate

    Dimensions..10

    Fig. 4: Biot Number

    Variables

    11

    Figure 5: Large Aluminum

    Plate...12

    Figure 6: Small Aluminum

    Plate..13

    Figure 7:

    Furnace

    ....13

    Figure 8: Experimental

    Schematic..

    15

    Figure 9: Experimental

    Photo..

    15

    Figure 10: Three dimensional depiction of the test matrix..

    ..18

    Figure 11: Pareto Chart..

    ..20

    8

  • 8/8/2019 Tuesday Cuddly Wombats Ellis Report2

    9/39

    Figure 12: Factor A Response

    Plot....20

    Figure 13: Factor C Response

    Plot....21

    Figure 14: Interaction of AB Response

    Plot.21

    Figure 15: 3 dimensional test matrix with response

    values...22

    Figure 16: Residual

    Plot

    ....23

    Figure 17: Large Plate Contour

    Plot..24

    Figure 18: Small Plate Contour

    Plot...24

    Figure 19: Large Plate Thermocouple Calibration

    Curve....28

    Figure 20: Small Plate Thermocouple Calibration

    Curve....29

    9

  • 8/8/2019 Tuesday Cuddly Wombats Ellis Report2

    10/39

    1. Nomenclature

    A Plate Surface Area FactorB Initial Temperature Factor

    C Air Flow Rate Factor

    h Heat Transfer Coefficient

    Se Standard Deviation

    n Replicates

    df Degrees of Freedom

    DL Decision Limit

    T Temperature at time t

    T Air temperature

    Ti Initial Temperature

    t Time (in seconds)

    As Surface Area

    Density

    V Volume

    c Specific heat

    Bi Biot number

    Ts Surface temperature

    RcondThermal resistance due to conduction

    RconvThermal resistance due to condvection

    DMM Digital Multimeter

    k Thermal Conductivity

    Rex Reynolds Number

    Pr Prandtl Numberu Fluid velocity

    Viscosity

    S2 VarianceSe Standard deviation of errorSeff Standard deviation of effect

    10

  • 8/8/2019 Tuesday Cuddly Wombats Ellis Report2

    11/39

  • 8/8/2019 Tuesday Cuddly Wombats Ellis Report2

    12/39

    temperature variations in the fluid [1]. As can be seen in Figure 2, with

    a hot object and a cold fluid, the fluid is warmer near the surface of the

    object, so the fluid rises due to a decrease in density. Depending on

    the situation, it is possible to consider on type of convection negligible,

    or it may be necessary to analyze both types of convection.

    Fig. 1: Forced Convection (2)

    Fig. 2: Natural Convection (2)

    The general equation for convective heat transfer is:

    q=hAs(Ts-T) (1)

    In this experiment, it was assumed that forced convection was

    significant and free convection was insignificant. This is a safe

    assumption because for this experiment, a fan was moving air past

    12

  • 8/8/2019 Tuesday Cuddly Wombats Ellis Report2

    13/39

    both sides of an aluminum plate. Certainly free convection existed in

    this experiment, however it can be assumed to be insignificant based

    on the experimental setup.

    To calculate the heat transfer coefficient in this experiment, the

    lumped capacitance method was used. The lumped capacitance

    method simplifies much more complicated analysis methods by

    assuming that the thermal resistance due to conduction within the

    solid is small compared with the thermal resistance between the solid

    and its surroundings [1]. This assumes a relatively uniform

    temperature throughout the solid and performs an energy balance

    using a single temperature for the solid, rather than a temperature

    gradient within the solid. In order to make this assumption, the Biot

    number must be considered.

    Bi=Ts,1-Ts,2Ts,2-T=RcondRconv=hLk (2)

    To justify the use of the lumped capacitance method:

    Bi

  • 8/8/2019 Tuesday Cuddly Wombats Ellis Report2

    14/39

    Fig. 3: Large and Small Aluminum Plate Dimensions

    Fig. 4: Biot Number Variables

    Using the lumped capacitance method, the heat transfer

    coefficient can be calculated.

    T-TTi-T=exp-hAsVct (4)

    Controlled FactorsPlate surface areaInitial temperature

    Air flow rateResponse VariableHeat transfer coefficient

    Uncontrollable FactorsEnvironmental factors (ambient pressure, air temperature, etc.)ConductionRadiation

    Factors Not Considered

    14

  • 8/8/2019 Tuesday Cuddly Wombats Ellis Report2

    15/39

    Free convectionPlates hanging at an angle

    15

  • 8/8/2019 Tuesday Cuddly Wombats Ellis Report2

    16/39

    3.Experimental Arrangement

    3.1 FacilitiesThe experiment was conducted in room 303 of the Ralph G.

    Anderson building, part of the University of Kentuckys College of

    Engineering. The room was equipped with a furnace, aluminum plates,

    hangers to hold the plates, fans, and measurement equipment. The

    large aluminum plate can be seen in Figure 5, the small aluminum

    plate can be seen in Figure 6, and the furnace can be seen in Figure 7.

    Table 1 lists the complete set of equipment.

    Table 1: List of Equipment and Serial Numbers

    EquipmentSerial Number (if

    applicable)

    1 DMMsCCL030910976

    CCL0202612195

    2Large Aluminum

    PlateN/A

    3Small Aluminum

    PlateN/A

    4 Fans N/A

    5Type K

    ThermocouplesN/A

    6 Stand/hangers N/A

    7 Anemometer 9416193

    Stopwatch N/A

    Furnace N/A

    16

  • 8/8/2019 Tuesday Cuddly Wombats Ellis Report2

    17/39

    Fig. 5: Large Aluminum Plate

    Fig. 6: Small Aluminum Plate

    17

  • 8/8/2019 Tuesday Cuddly Wombats Ellis Report2

    18/39

    Fig. 7: Furnace

    3.2 Diagnostics & Sensor Calibration

    Two thermocouples were used during this experiment. They

    were embedded into the aluminum plates at used to measure the

    temperature. As was discussed in the Background and Theory (section

    2), the plates were assumed to have a uniform temperature, so only

    one thermocouple was needed in each plate. Further calibration

    details can be found in Appendix A.

    3.2.1 Small Plate Thermocouple/DMM

    One Type K thermocouple was connected to a DMM to measure

    the temperature of the small aluminum plate. Using this system,

    temperatures were recorded for boiling water and for an ice bath. A

    linear calibration curve was created using these two reference points.

    All measurements in the experiment were between these two

    reference temperatures. More calibration details can be found inAppendix A. The DMM/thermocouple calibration curve is equation 7

    below. The variable x is the true temperature and y is the measured

    temperature in degrees Fahrenheit.

    y=1.0588x-34.24 (7)

    18

  • 8/8/2019 Tuesday Cuddly Wombats Ellis Report2

    19/39

    3.2.2 Large Plate Thermocouple/DMM

    Similarly, a Type K thermocouple was connected to a DMM to

    measure the temperature of the large aluminum plate. Again,

    temperatures were recorded for boiling water and for an ice bath.

    Using these two reference points, a linear calibration curve was

    created. All measurements in the experiment were between these two

    reference temperatures. More details can be found in Appendix A.

    The DMM/thermocouple calibration curve is seen in equation 8 below.

    The variable x is the true temperature and y is the measured

    temperature in degrees Fahrenheit.

    y=1.0651x-38.41 (8)

    3.2.3 Air Flow Rate

    To measure the air flow rate, a digital anemometer was used.

    The plates and fan were arranged such that air flowed past both sides

    of the plate at equal velocities. This was verified by measuring the air

    speed on both sides of the hanging aluminum plate directly prior to

    taking measurements.

    3.3 Experimental Set-up

    A diagram of out experimental set-up can be seen in Figure 8

    below. The stand was placed in front of the fan such that the air flow

    hit the thin edge of the plate, then passed along the broad sides of the

    plate. It was set up such that the air passed at equal velocities on both

    sides of the plate. The thermocouple was embedded into a small hole

    that was drilled through the middle of the plate and secured there to

    ensure that the measured temperature was the temperature of the

    plate, not the passing air. Two entire setups were constructed so that

    the fans would not have to be moved to change the high flow rate and

    low flow rate treatments, therefore reducing variability.

    19

  • 8/8/2019 Tuesday Cuddly Wombats Ellis Report2

    20/39

    Fig. 8: Experimental Schematic

    Fig. 9: Experimental Photo

    3.4 Experimental Procedure1. Locate all necessary equipment identified in Section 3.1

    Facilities.

    2. Calibrate the thermocouples as described in Section 3.2

    Diagnostics and Sensor Calibration.

    20

  • 8/8/2019 Tuesday Cuddly Wombats Ellis Report2

    21/39

    3. Align fans with plate hangers. Measure flow rates on both

    sides of each plate to ensure accuracy.

    4. Embed the thermocouples into the aluminum plates.

    5. Heat aluminum plates to a temperature hotter than 150F or

    120F depending on which treatment is being conducted. Use

    caution when handling hot plates and working with furnace.

    6. Place hot aluminum plate on hanger and turn on fan. Wait

    until the temperature of the plate reaches 150F or 120F

    (depending on which treatment is being conducted).

    7. Record temperature measurements every 10 seconds until the

    plate temperature has dropped to 120F for the high

    temperature treatments, or 85F for the low temperature

    treatments.

    8. Repeat steps 5-7 for all treatments defined by the test matrix.

    9. Turn off furnace and allow aluminum plates to cool

    completely.

    10. Conduct statistical analysis and draw conclusions.

    4. Results and Analysis

    5.1 Test Matrix

    The following tables outline the factorial design approach for the

    experiment. The first table identifies the experimental factors and

    defines the high and low levels of each one. The second table shows

    the eight different treatments that were executed in the experiment.

    Table 2: Experimental Factors

    Experimental Factors

    ASurface Area 0.0758m2 +

    0.0291m2 -

    21

  • 8/8/2019 Tuesday Cuddly Wombats Ellis Report2

    22/39

    B

    Initial

    Temperature 150F +

    120F -

    C Air Flow Rate 2.5 m/s +

    1.5 m/s -

    Table 3: Test matrix with the eight treatments defined.

    Test MatrixTreatme

    nt Factors Interactions

    A B C AB AC BC ABC

    1 - - - + + + -

    2 + - - - - + +

    3 - + - - + - +

    4 + + - + - - -5 - - + + - - +

    6 + - + - + - -

    7 - + + - - + -

    8 + + + + + + +

    22

  • 8/8/2019 Tuesday Cuddly Wombats Ellis Report2

    23/39

    Figure 10: Three dimensional depiction of the test matrix

    5.2 Experimental Calculations

    In this experiment, significant factors were identified by

    calculating the effect and comparing it to the decision limit. For any

    factor or interaction, if the effect is greater than the decision limit, that

    factor or interaction is considered significant. In this experiment, the

    decision limit is 1.89 and factors A and C, as well as interaction AB are

    significant. Appendix B and Appendix C show the details of converting

    the response temperatures to heat transfer coefficients.

    23

  • 8/8/2019 Tuesday Cuddly Wombats Ellis Report2

    24/39

    Table 4: Test matrix with heat transfer coefficients, averages, and variance.

    Test Matrix

    Factors Interactions Replicate

    Varian

    ce

    A B C AB AC BC ABC I II III

    Avera

    ge S2

    1 - - - + + + -

    31.4

    1

    36.5

    2

    31.4

    1 33.11 8.72

    2 + - - - - + +

    33.9

    4

    28.7

    8

    31.3

    2 31.35 6.65

    3 - + - - + - +

    31.0

    0

    35.6

    1

    34.0

    4 33.55 5.49

    4 + + - + - - -

    27.0

    9

    27.0

    9

    28.5

    9 27.59 0.74

    5 - - + + - - +

    28.9

    8

    28.9

    8

    28.9

    8 28.98 0.00

    6 + - + - + - -

    28.7

    8

    26.3

    3

    31.3

    2 28.81 6.23

    7 - + + - - + -

    29.5

    3

    34.0

    4

    28.0

    8 30.55 9.64

    8 + + + + + + +

    27.0

    9

    27.0

    9

    25.6

    3 26.60 0.71

    Se 2.18

    Y+

    114.

    36

    118.

    29

    114.

    95

    116.

    28

    122.

    07

    121.

    61

    120.

    48 Seff 0.89

    Y-

    126.

    19

    122.

    25

    125.

    60

    124.

    26

    118.

    47

    118.

    93

    120.

    06 DL 1.89Y+)

    av

    28.5

    9

    29.5

    7

    28.7

    4

    29.0

    7

    30.5

    2

    30.4

    0

    30.1

    2 alpha 0.05Y-)a

    v

    31.5

    5

    30.5

    6

    31.4

    0

    31.0

    6

    29.6

    2

    29.7

    3

    30.0

    2 n 3Effe

    ct -2.96 -0.99 -2.66 -1.99 0.90 0.67 0.10 df 16

    t

    alpha 2.12

    TR 8

    N 24

    24

  • 8/8/2019 Tuesday Cuddly Wombats Ellis Report2

    25/39

    Figure 11: Pareto Chart

    5.3 Response Plots

    For all factors and interactions, mean responses were calculated.

    These mean responses can be seen in the table above. Using these

    values, response plots were created. Details for the calculations used

    to generate these plots can be found in Appendix D.

    Figure 12: Factor A Response Plot

    Figure 13: Factor C Response Plot

    Figure 14: Interaction of AB Response Plot

    25

  • 8/8/2019 Tuesday Cuddly Wombats Ellis Report2

    26/39

    Figure 15: 3 dimensional test matrix with response values

    5.4 Regression Model and Residuals

    A regression model was generated for the responses from this

    experiment. Using Microsoft Excel, a plot was generated based on

    Equation 9, which can be seen below. This regression plot can be seen

    in Figure 15. Appendix E shows the table used to generate the residual

    plot.

    Y=30.07-1.48A-1.33C-1.00AB (9)

    Figure 16: Residual Plot

    5.6 Contour Plots

    The contour plots below were created using the regression model

    equation. For these plots, the factors were changed from (-1) to (1) at

    intervals of (0.2). Due to the discrete sizes of the plates, plots were

    26

  • 8/8/2019 Tuesday Cuddly Wombats Ellis Report2

    27/39

    created that show the variation in the initial temperature and the air

    flow rate at each plate size. The results were used to generate Table

    14 and Table 15 in Appendix F, which were in turn used to generate

    the contour plots seen below as Figure 17 and Figure 18, respectively.

    Figure 17: Large Plate Contour Plot

    Figure 18: Small Plate Contour Plot

    5.Discussion and Conclusions

    The objective of this experiment was to determine the effects

    that surface area, initial temperature, and air flow rate have on the

    heat transfer coefficient of a vertical aluminum plate. As can be seen

    in Figure 11, the surface area and the air flow rate were determined to

    be significant factors. Additionally, the interaction between surface

    area and initial temperature was also determined to have a significant

    impact on the heat transfer coefficient of the plate.

    The most significant factor was determined to be the surfacearea. As can be seen in the response plot for factor A, the smaller

    plate yielded the highest heat transfer coefficients. This result is

    consistent with the base equation (Equations 4) used to calculate the

    heat transfer coefficient. The equation for heat transfer coefficient,

    found by manipulating Equation 4, can be seen here.

    h=lnT-TiT-TVcAst (10)

    It is apparent that surface area is inversely related to the heat transfer

    coefficient. The experimental results support this.

    The next significant factor is the air flow rate past the plate. The

    results show that as the air flow rate increases, the heat transfer

    coefficient decreases. This result was an unexpected result. Air

    velocity is not a direct factor in the equation used for heat transfer

    27

  • 8/8/2019 Tuesday Cuddly Wombats Ellis Report2

    28/39

    coefficient. However, it can be studied another way. According to

    Incropera et. al., for a flat plate in parallel flow, the heat transfer

    coefficient is

    h=kx0.664Rex1/2Pr1/3 (11)

    Also, it is known that

    Rex=ux (12)

    Equation 12 shows that the Reynolds number is directly proportional to

    the velocity of the fluid, u. Furthermore, equation 8 shows that the

    heat transfer coefficient is directly related to the heat transfer

    coefficient. Based on these equations, the heat transfer coefficient

    was expected to be directly proportional to the velocity. However, the

    experimental results showed the opposite correlation. More

    experiments should be conducted to explore this phenomenon. The

    experimental setup and equipment is a strong possibility for this error.

    The air speed was measured on both sides of the plate prior to each

    series of temperature readings. However, the low air flow rate was 1.7

    m/s and the high air flow rate was 2.5 m/s. This was limited by the

    capabilities of the fans in the lab. It is possible while the

    measurements were being taken, other environmental factors had a

    great impact on the heat transfer coefficient than the slight variation in

    air speed. If conducted again, we would have a much greater

    difference between the high and low air flow rates.

    This experiment also showed that the initial temperature of the

    plate was not a significant factor in the heat transfer coefficient. The

    results show that temperature dropped with time at approximately the

    same linear rate across all of the temperatures that were used in this

    experiment. This factor could be investigated further by using

    temperatures that had a more significant difference. However, for the

    temperatures used in this experiment, the initial temperature of the

    plate is an insignificant factor.

    28

  • 8/8/2019 Tuesday Cuddly Wombats Ellis Report2

    29/39

    There are a few major potential sources of error in this

    experiment. Slight variations in the setup could have a significant

    effect on the air flow around the plate. In order to create parallel flow

    across both sides of a vertical plate, the fan and plate had to be

    oriented very precisely, and this had to be repeated for all trials in the

    experiment. Due to heating and moving the plates and turning the fan

    on and off, there is strong potential for misaligning the plate and fan

    setup. Although the air flow rates were monitored at the thermocouple

    location on both sides of the plate prior to each reading, variation

    could still exist and have a significant impact on the experimental

    results.

    29

  • 8/8/2019 Tuesday Cuddly Wombats Ellis Report2

    30/39

    6. References

    1) Incropera, F., DeWitt, D., Bergman, T., and Lavine, A.,Introduction to Heat Transfer, John Wiley and Sons, Inc, NewYork, 2007. (pages 6-9)

    2) http://images.anandtech.com/old/cooling/heatsinkguide/convection.gif(forced convection image)

    3) Montgomery, Douglas C. Design and Analysis of Experiments. 7th. Danvers:John Wiley & Sons, INC., 2008.

    30

    http://images.anandtech.com/old/cooling/heatsinkguide/convection.gifhttp://images.anandtech.com/old/cooling/heatsinkguide/convection.gifhttp://images.anandtech.com/old/cooling/heatsinkguide/convection.gifhttp://images.anandtech.com/old/cooling/heatsinkguide/convection.gifhttp://images.anandtech.com/old/cooling/heatsinkguide/convection.gif
  • 8/8/2019 Tuesday Cuddly Wombats Ellis Report2

    31/39

    Appendices

    8.1 Appendix A: Thermocouple/DMM Calibration

    Both thermocouples used in this experiment were calibrated inorder to be certain to yield accurate temperature readings throughout

    the experiment. In order to calibrate the thermocouples, temperature

    readings were taken at known temperatures (freezing and boiling), and

    a calibration curve was constructed. The thermocouples were inserted

    into boiling water and an ice bath. For both thermocouples, the

    readings and calibration curves can be seen here. In the calibration

    equations, Equation 7 and Equation 8, x is the actual temperature

    and y is the measured temperature, measured in degrees Fahrenheit.

    Large Plate TC

    Table 5: Temperatures for large plate thermocouple calibration.

    Ideal

    (R)

    Measured

    (R)Freezi

    ng 492 498

    Boiling 672 667

    Figure 19: Large Plate Thermocouple Calibration Curve

    Small Plate TC

    Table 6: Temperatures for small plate thermocouple calibration.

    Ideal

    (R)

    Measured

    (R)

    Freezing 492 497

    Boiling 672 667

    Figure 20: Small Plate Thermocouple Calibration Curve

    31

  • 8/8/2019 Tuesday Cuddly Wombats Ellis Report2

    32/39

  • 8/8/2019 Tuesday Cuddly Wombats Ellis Report2

    33/39

    Table 8: Results of Heat Transfer Coefficient calculations with levels.

    Test MatrixFactor

    s Interactions Replicate Variance

    A B C

    A

    B

    A

    C

    B

    C ABC I II III Average S2

    1 - - - + + + - 31.41 36.52 31.41 33.11 8.72

    2 + - - - - + + 33.94 28.78 31.32 31.35 6.65

    3 - + - - + - + 31.00 35.61 34.04 33.55 5.49

    4 + + - + - - - 27.09 27.09 28.59 27.59 0.74

    5 - - + + - - + 28.98 28.98 28.98 28.98 0.00

    6 + - + - + - - 28.78 26.33 31.32 28.81 6.23

    7 - + + - - + - 29.53 34.04 28.08 30.55 9.64

    8 + + + + + + + 27.09 27.09 25.63 26.60 0.71

    33

  • 8/8/2019 Tuesday Cuddly Wombats Ellis Report2

    34/39

    8.3 Appendix C: Decision Limit and Effect calculations

    S2=i=1n(yi-y)2n-1 (13)

    Se=s2/TR (14)

    Seff=Se4/N (15)

    DF=n-1TR (16)

    DL=Sefft (17)

    Table 9: Results of Statistical Analysis.

    Se 2.18Seff 0.89

    DL 1.89

    alpha 0.05

    n 3

    df 16

    t alpha 2.12

    TR 8

    N 24

    Table 10: Effect Calculations

    Y+ 114.36118.29 114.95116.28122.07 121.61120.48

    Y- 126.19122.25 125.60124.26118.47 118.93120.06

    Y+)av 28.59 29.57 28.74 29.07 30.52 30.40 30.12

    Y-)av 31.55 30.56 31.40 31.06 29.62 29.73 30.02

    Effect -2.96 -0.99 -2.66 -1.99 0.90 0.67 0.10

    34

  • 8/8/2019 Tuesday Cuddly Wombats Ellis Report2

    35/39

    8.4 Appendix D: Response Plot Calculations

    Standard error calculations were done using Microsoft Excel.The

    response plots seen in section 5.3 were created using the numbersbelow. The calculation for Error Percent can be seen in equation 18.

    Table 11: Error Calculations

    Term Mean

    Standard

    Error Error Percent

    All 30.07

    A -1 31.55 2.3 7.29

    1 28.59 2.3 8.04

    B -1 30.56 0.06 0.201 29.57 0.06 0.20

    C -1 31.40 1.2 3.82

    1

    125.6

    0 1.2 0.96

    AB -1 31.06 0.9 2.90

    1 29.07 0.9 3.10

    BC -1 29.62 0.2 0.68

    1 30.52 0.2 0.66

    AC -1 29.73 0.1 0.34

    1 30.40 0.1 0.33ABC -1 30.02 0.07 0.23

    1 30.12 0.07 0.23

    Error Percent=100Standard ErrorMean (18)

    35

  • 8/8/2019 Tuesday Cuddly Wombats Ellis Report2

    36/39

    8.5 Appendix E: Residual Model Calculations

    The regression equation, Equation 9 was used to generate theresidual plot. The equation was used to calculate the Model value in

    the table below. The residual plot, Figure 16, was created using these

    calculations.

    Error=Model-Response (19)

    Table 13: Residual Error Calculations

    Treatme

    nt

    Significant

    factors/interactions Model Error

    A C AB I II III

    1 -1 -1 -1 33.88

    2.4748

    83

    -

    2.6401

    8

    2.4748

    83

    a 1 -1 -1 30.92

    -

    3.0237

    9

    2.1352

    92

    -

    0.4006

    3

    b -1 1 -1 31.22

    0.2217

    06

    -

    4.3860

    2

    -

    2.8167

    1

    ab 1 1 -1 28.26

    1.1670

    11

    1.1670

    11

    -

    0.3261

    5

    c -1 -1 1 31.88

    2.9007

    56

    2.9007

    56

    2.9007

    56

    ac 1 -1 1 28.92

    0.1352

    92

    2.5895

    94

    -

    2.4006

    3

    bc -1 1 1 29.22

    -

    0.3064

    2

    -

    4.8167

    1

    1.1356

    06abc 1 1 1 26.26 -

    0.8329

    -

    0.8329

    0.6314

    96

    36

  • 8/8/2019 Tuesday Cuddly Wombats Ellis Report2

    37/39

    9 9

    37

  • 8/8/2019 Tuesday Cuddly Wombats Ellis Report2

    38/39

    8.6 Appendix F: Contour Plot Calculations

    Using the regression model, Equation 9, the contour plots, Figure17 and Figure 18, were created. These plots vary the significant

    factors from (-1) to (1) in the regression model. These plots show

    initial temperature vs air flow rate with either the large surface area or

    the small surface area. In this experiment, the surface area was

    discrete based on the size of the plates available, while the initial

    temperature and air flow rate could be more precisely controlled.

    Therefore, contour plots were generated comparing these two

    variables. The tables used to make these plots are included here.

    Table 14: Contour Plot Calculations for Large Plate

    Factor C (Air Flow Rate)

    -1 -0.8 -0.6 -0.4 -0.2 0 0.2 0.4 0.6 0.8 1Fac

    tor

    B

    (Ini

    tial

    Te

    mp

    era

    tur

    e)

    -1

    30.9

    2

    30.6

    5

    30.3

    9

    30.1

    2

    29.8

    5

    29.5

    9

    29.3

    2

    29.0

    6

    28.7

    9

    28.5

    2

    28.2

    6-

    0.8

    30.7

    2

    30.4

    5

    30.1

    9

    29.9

    2

    29.6

    6

    29.3

    9

    29.1

    2

    28.8

    6

    28.5

    9

    28.3

    2

    28.0

    6

    -

    0.6

    30.5

    2

    30.2

    5

    29.9

    9

    29.7

    2

    29.4

    6

    29.1

    9

    28.9

    2

    28.6

    6

    28.3

    9

    28.1

    2

    27.8

    6-

    0.4

    30.3

    2

    30.0

    6

    29.7

    9

    29.5

    2

    29.2

    6

    28.9

    9

    28.7

    2

    28.4

    6

    28.1

    9

    27.9

    2

    27.6

    6-

    0.2

    30.1

    2

    29.8

    6

    29.5

    9

    29.3

    2

    29.0

    6

    28.7

    9

    28.5

    2

    28.2

    6

    27.9

    9

    27.7

    3

    27.4

    6

    0

    29.9

    2

    29.6

    6

    29.3

    9

    29.1

    2

    28.8

    6

    28.5

    9

    28.3

    3

    28.0

    6

    27.7

    9

    27.5

    3

    27.2

    6

    0.2

    29.7

    2

    29.4

    6

    29.1

    9

    28.9

    2

    28.6

    6

    28.3

    9

    28.1

    3

    27.8

    6

    27.5

    9

    27.3

    3

    27.0

    6

    0.4

    29.5

    2

    29.2

    6

    28.9

    9

    28.7

    3

    28.4

    6

    28.1

    9

    27.9

    3

    27.6

    6

    27.3

    9

    27.1

    3

    26.8

    6

    0.6

    29.3

    3

    29.0

    6

    28.7

    9

    28.5

    3

    28.2

    6

    27.9

    9

    27.7

    3

    27.4

    6

    27.1

    9

    26.9

    3

    26.6

    60.8 29.1

    3

    28.8

    6

    28.5

    9

    28.3

    3

    28.0

    6

    27.7

    9

    27.5

    3

    27.2

    6

    27.0

    0

    26.7

    3

    26.4

    6

    38

  • 8/8/2019 Tuesday Cuddly Wombats Ellis Report2

    39/39

    1

    28.9

    3

    28.6

    6

    28.3

    9

    28.1

    3

    27.8

    6

    27.5

    9

    27.3

    3

    27.0

    6

    26.8

    0

    26.5

    3

    26.2

    6

    Table 15: Contour Plot Calculations for Small Plate

    Factor C (Air Flow Rate)

    -1 -0.8 -0.6 -0.4 -0.2 0 0.2 0.4 0.6 0.8 1

    Fa

    cto

    r B

    (Ini

    tial

    Te

    mp

    era

    tur

    e)

    -1 33.88

    33.6

    1

    33.3

    4

    33.0

    8

    32.8

    1

    32.5

    5

    32.2

    8

    32.0

    1

    31.7

    5

    31.4

    8

    31.2

    1

    -0.8 33.68

    33.4

    1

    33.1

    4

    32.8

    8

    32.6

    1

    32.3

    5

    32.0

    8

    31.8

    1

    31.5

    5

    31.2

    8

    31.0

    1

    -0.6 33.48

    33.2

    1

    32.9

    5

    32.6

    8

    32.4

    1

    32.1

    5

    31.8

    8

    31.6

    1

    31.3

    5

    31.0

    8

    30.8

    1

    -0.4 33.28

    33.0

    1

    32.7

    5

    32.4

    8

    32.2

    1

    31.9

    5

    31.6

    8

    31.4

    1

    31.1

    5

    30.8

    8

    30.6

    2

    -0.2 33.08

    32.8

    1

    32.5

    5

    32.2

    8

    32.0

    1

    31.7

    5

    31.4

    8

    31.2

    2

    30.9

    5

    30.6

    8

    30.4

    2

    0 32.88

    32.6

    1

    32.3

    5

    32.0

    8

    31.8

    1

    31.5

    5

    31.2

    8

    31.0

    2

    30.7

    5

    30.4

    8

    30.2

    2

    0.2 32.68

    32.4

    1

    32.1

    5

    31.8

    8

    31.6

    2

    31.3

    5

    31.0

    8

    30.8

    2

    30.5

    5

    30.2

    8

    30.0

    2

    0.4 32.48

    32.2

    2

    31.9

    5

    31.6

    8

    31.4

    2

    31.1

    5

    30.8

    8

    30.6

    2

    30.3

    5

    30.0

    8

    29.8

    2

    0.6 32.28

    32.0

    2

    31.7

    5

    31.4

    8

    31.2

    2

    30.9

    5

    30.6

    8

    30.4

    2

    30.1

    5

    29.8

    9

    29.6

    2

    0.8 32.0831.8

    231.5

    531.2

    831.0

    230.7

    530.4

    830.2

    229.9

    529.6

    929.4

    2

    1 31.88

    31.6

    2

    31.3

    5

    31.0

    8

    30.8

    2

    30.5

    5

    30.2

    9

    30.0

    2

    29.7

    5

    29.4

    9

    29.2

    2