Top Banner

of 30

MAR 2010 - Course Work 1

Apr 06, 2018

Download

Documents

Welcome message from author
This document is posted to help you gain knowledge. Please leave a comment to let me know what you think about it! Share it to your friends and learn new things together.
Transcript
  • 8/3/2019 MAR 2010 - Course Work 1

    1/30

    Rod Sampson - School of Marine Science and Technology

    Preliminary Predictionof Power

    CourseworkMAR2010

  • 8/3/2019 MAR 2010 - Course Work 1

    2/30

    Rod Sampson - School of Marine Science and Technology

    Preliminary prediction of power for:

    A single screw bulk carrier 15 knot service speed

    The contract requires that on a fully loaded

    trial the ship achieves a speed 1 knot greater

    than the required service speed with the engines

    developing 85% MCP

    Plot PE(trial) PE(service)& VSvs

  • 8/3/2019 MAR 2010 - Course Work 1

    3/30

    Rod Sampson - School of Marine Science and Technology

  • 8/3/2019 MAR 2010 - Course Work 1

    4/30

    Rod Sampson - School of Marine Science and Technology

    Vessel Particulars

    LBP = 135.34m

    B = 19.30m

    T = 9.16mCB = 0.704

    Enter your speed and

    deadweight into

    NEWAT2 to obtainthese values

  • 8/3/2019 MAR 2010 - Course Work 1

    5/30

    Rod Sampson - School of Marine Science and Technology

    Vessel Particulars

    LBP = 135.34mB = 19.30m

    T = 9.16m

    CB = 0.704

    LBP = 444.03 feetB = 63.32 feet

    T = 30.05 feet

    CB = 0.704

    Take GREAT care with your units

    Convertto feet

  • 8/3/2019 MAR 2010 - Course Work 1

    6/30

    Rod Sampson - School of Marine Science and Technology

    Stage 1 - Effective Power Prediction

    Objective - use average C values to estimate PEfor trial and service condition

    Note:For the C notation you may use

    (C), or C

    ITTC standard notation is and will be adopted hereCc

  • 8/3/2019 MAR 2010 - Course Work 1

    7/30

    Rod Sampson - School of Marine Science and Technology

    Stage 1 - Effective Power Prediction

    Specify a speed range which includes the trial

    and service speeds

    2kne.g. of the trial speed

    Vs(trial) = Vs(service) + 1knot = 16 knots

    Vsrange = Vs(trial) 2knots = 14 ~ 18 knots

  • 8/3/2019 MAR 2010 - Course Work 1

    8/30

  • 8/3/2019 MAR 2010 - Course Work 1

    9/30

    Rod Sampson - School of Marine Science and Technology

    It is not important to use exact speed values in knots

    Use the range for the speed

    This will avoid double interpolation in your

    method causing an error.

    It is also SIMPLER to use

    VsL

  • 8/3/2019 MAR 2010 - Course Work 1

    10/30

    Rod Sampson - School of Marine Science and Technology

    VsL

    0

    500

    1000

    1500

    2000

    EffectivePower(kW

    )

    0.65

    0.700.75

    0.80.85

    13.69 knots

    17.91 knots

    Speed units are arbitrary as you need to interrogate

    graph both ways therefore USEVsL

  • 8/3/2019 MAR 2010 - Course Work 1

    11/30

    Rod Sampson - School of Marine Science and Technology

    The model data used is the BSRA standard series. It wasgenerated for a standard vessel of:

    400ft x 55ft x 24ft

    Therefore to use it you must first scale your vessel down

    to this size

  • 8/3/2019 MAR 2010 - Course Work 1

    12/30

    Rod Sampson - School of Marine Science and Technology

    Actual ship dimensions

    L x B x T = 135.34 x 19.30 x 9.16 [m]

    L x B x T = 444.03 x 63.32 x 30.05 [ft]

    BSRA ship dimensions

    LB BB TB = 400 x 55 x 24 [ft]

  • 8/3/2019 MAR 2010 - Course Work 1

    13/30

    Rod Sampson - School of Marine Science and Technology

    Scale factor

    =L

    LB

    444.03

    400= 1.11 = 1.11

    LSD BSD TSDL

    B

    T

    444.

    031.11

    =

    L

    B

    T

    =

    =

    =

    = 27.027 ft

    = 57.045 ft

    = 400 ft

    Dimensions

    correct for length

    63.32

    30.

    05

  • 8/3/2019 MAR 2010 - Course Work 1

    14/30

  • 8/3/2019 MAR 2010 - Course Work 1

    15/30

    Rod Sampson - School of Marine Science and Technology

    Volume of actual ship ( )

    = CB LB T

    = 0.704 135.34 19.3 9.16

    = 16844.25m3

  • 8/3/2019 MAR 2010 - Course Work 1

    16/30

  • 8/3/2019 MAR 2010 - Course Work 1

    17/30

    Rod Sampson - School of Marine Science and Technology

    O values are now required from Table 2

    by interpolation

    Actual ship L = 444.03 or 135.34m

    135 0.0732

    140 0.0726O1 = 0.07320

    Scaled down ship L = 400 or 121.92m

    120 0.0743

    125 0.0739O2 = 0.07406

  • 8/3/2019 MAR 2010 - Course Work 1

    18/30

    Rod Sampson - School of Marine Science and Technology

    O values are now required from Table 2

    by interpolation

    Actual ship O1 = 0.07320

    Scaled down ship O2 = 0.07406

    1 O2 = 0.07320 0.07406

    1 O2 = 0.00086

  • 8/3/2019 MAR 2010 - Course Work 1

    19/30

    Rod Sampson - School of Marine Science and Technology

    Using interpolate for using Table 1VsL

    CB

    to obtainCc

    average

    0.65 0.70

    0.700 0.694 0.713

    0.701 0.698 0.724

    0.704 0.6956 0.7174

    If you use you do this once for each set,

    otherwise you interpolate for AND for

    VsL

    VsL

    CB

  • 8/3/2019 MAR 2010 - Course Work 1

    20/30

  • 8/3/2019 MAR 2010 - Course Work 1

    21/30

    Rod Sampson - School of Marine Science and Technology

    Calculate Lc

    Lc=

    VgL

    4

    Lc

    = 1.055 VL

    (Lc)0.175Finally

    knots

    Feet

  • 8/3/2019 MAR 2010 - Course Work 1

    22/30

    Rod Sampson - School of Marine Science and Technology

    (Cc)DesignCalculate

    Calculate Kc

    Kc =V

    1

    6

    4

    2gKc =

    V

    168441

    6

    4

    2g

    Kc

    = 0.22354 V

    (your volume)

    (metres/sec)

    (Cc)Design = (Cc)400 + [O1 O2] S

    c (Lc)0.175

  • 8/3/2019 MAR 2010 - Course Work 1

    23/30

    Rod Sampson - School of Marine Science and Technology

    Calculate displacement

    =g = 1025 9.81 16884

    =1 .6937 108(N)

    (kg)

    (large!)

    (Kc)2 = (0.22354 V)2 1.6937 108

    (Kc)2 = 8463472.7 V2 (metres/sec)

  • 8/3/2019 MAR 2010 - Course Work 1

    24/30

    Rod Sampson - School of Marine Science and Technology

    Total resistance and effective power

    RT =

    Cc

    Design

    (Kc)2

    1000

    RT = CcDesign

    8463472.7 V2

    1000

    PE =RT

    1000 V[kW]

    (metres/sec)

    (metres/sec)

  • 8/3/2019 MAR 2010 - Course Work 1

    25/30

    Rod Sampson - School of Marine Science and Technology (1 + x

    (1 + x)froude = 0.973

    Calculate sea margin

    (1 + x)froude = (0.44 + 2.229 [L]1

    4 + 10.058 [L]1)1

    20

    (where L is your vessel length)

  • 8/3/2019 MAR 2010 - Course Work 1

    26/30

    Rod Sampson - School of Marine Science and Technology

    Final Power Prediction

    PE(trial) = (1 + x)froude PE

    PE(service) = 1.2 PE(trial)

  • 8/3/2019 MAR 2010 - Course Work 1

    27/30

    Rod Sampson - School of Marine Science and Technology

    Assemble data in a spreadsheet

  • 8/3/2019 MAR 2010 - Course Work 1

    28/30

    Rod Sampson - School of Marine Science and Technology

    Plot PE(trial) PE(service)& vs Vs

    0

    2000

    4000

    6000

    8000

    10000

    12000

    10 12 14 16 18 20Speed (knot)

    Po

    wer(kW)

    PE (kW)

    Pe Trial (kW)

    PE Service

  • 8/3/2019 MAR 2010 - Course Work 1

    29/30

    Rod Sampson - School of Marine Science and Technology

    A basic report is required for the assignment.

    Take 1 speed e.g close to your design speed and

    provide a worked example for this speed showing

    how you generated the spreadsheet

    If you make an error (very easy on this assignment)

    the worked example should provide method marks

    ensuring a good grade

  • 8/3/2019 MAR 2010 - Course Work 1

    30/30

    Rod Sampson - School of Marine Science and Technology

    End of Section 1