Welcome to the Ship Resistance...

Welcome to the Ship Resistance Predictor!

What does this Excel Sheet do?

This Excel sheet helps you calculate the Total Calm Water Resistance for a Ship at a given forward speed

It also calculates from the resistance the Effective Power (P E ) required for propulsion

Formula

RF = Frictional Resistance as per ITTC 1957 friction ]formula

k1 = Form Factor describing viscous resistance of the Hull Form in relation to RF

RAPP = Resistance of Appendages

RW = Wave Resistance (Wave Making and Wave Breaking Resistance)

RB = Additional Pressure Resistance of Bulbous Bow near Water surface

RTR = Additional Pressure Resistance of Immersed Transom Stern

RA = Model-Ship Correlation Resistance

How to use this Excel Sheet

The user is asked for some inputs for the Vessel. The Input cells are highlighted in blue.

The user has to provide all the inputs highlighted in blue in the Worksheets "Inputs - Vessel" and "Inputs - Appendages".

ONLY INPUT THE CELLS HIGHLIGHTED IN BLUE. LEAVE ALL OTHER CELLS UNTOUCHED!

For some inputs, Tables and charts are required to be referred. These Tables and charts are provided alongwith for the user to enter these inputs.

In the 'Speeds' excel sheet, the speeds at which resistance is to be estimated have to be input.

Once all inputs and speeds are provided, the components of the calm water resistance are calculated in different worksheets to give the final Calm Water Resistance

for each speed. Then the resistance curve is plotted from the resistance values at different speeds

Limitations

1. This application is limited to a displacement vessel, with Hull forms resembling the average ship. It cannot be used for unusual hull forms, high speed crafts and barges

References

1. An Approximate Power Prediction Method, J.Holtrop and G.G.J.Mennen, 1982

2. A Statistical Power Prediction Method by J. Holtrop and G.G.J. Mennen, International Shipbuilding Progress, Vol. 25, October 1978.

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Change Log (Rev 02)

1. User can now input design speed at which the report will be generated. The curve will be generated for all speed values input by user in the "Speeds" worksheet

2. Bulbous bow resistance - formula corrected for the case when there is no bulbous bow

The total calm water resistance is given by:

RC = RF(1 + k1) + RAPP + RW + RB + RTR + RA

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Company Name:

Project Name:SHIP RESISTANCE Doc. No:

Date:

Revision No:

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Stern Shapes

Stern Shape Code

Particular Value Default Value Units Normal Section Shape 1Acceleration due to Gravity g 9.81 9.81 m/s2

V-shaped Sections 2

Density of air ρair 1.23 1.23 kg/m3U-Shaped Sections with Hogner Stern 3

Density of Water ρwater 1025 1025 kg/m3

Viscosity of Water ν 0.0000012 0.0000012 m2/s

Particular Value Units

Vessel Name Barge 1

Length Between Perpendiculars (LBP) LBP 200 m

Length on Waterline (LWL) L 205 204 m (Default value 1.02*LBP)

Breadth B 32 m

Depth D 15 m

Longitudinal Center of Buoyancy fwd of

Midship (+ve fwd and -ve aft of Midship) lcb -1.5375 2.00 m (Default value 0.01*LBP)

Mean Draft at Midship T 10 m

Trim (trim by aft +ve, by fwd -ve) Trim 0 m

Block Coefficient Cb 0.5716

Midship Section Coefficient CM 0.98

Waterplane Coefficient CW 0.75

Stern Type (See Table 1 and enter code) 3Transverse area of immersed part of Transom

Stern(only if the stern is transom stern,else

input 0) AT 16.000 m2

Ratio of Bulb Transverse Section Area to

Midship Area ABT/Amid 0.043 0.100 (Default value 0.1)

Vertical distance from baseline to center of

bow bulb cross sectional area hB 4.00 4.00 m (Default value 0.4T)

Angle of Half Entrance (angle of Waterline at

bow)* iE 12.170 12.17 degrees (Default Value: See Formula)

Wetted Surface Area* S 7354.32 7354.32 m2(Default Value: See Formula)

Forward Vessel Speed V 5.5 m/s

Operational Inputs

SHIP RESISTANCE CALCULATION - VESSEL INPUTS

General Particulars

Vessel Particulars

Principal Dimensions

Coefficients

Bow and Stern Information

Floating Status

Table 1: Stern Shape Types

*The default value of iE (Angle of Half entrance) is given by:

iE = 1 + 89 exp{-(L/B)0.80856 (1 - Cwp)0.30484(1 - Cp - 0.0225 lcb)0.6367 (LR/B)0.34574(100DV/L3)0.16302}, Cp =

Prismatic Coefficient, LR = Length of Run, Dv = Volumetric Displacement

Wetted Surface Area

*The default value of Wetted Surface is given by

S = L (2T + B) √CM (0.453 + 0.4425 CB - 0.2862 CM - 0.003467 B/T + 0.3696 CWP) + 2.38 ABT/CB

Particular Value Default Value Units Rudder Type Code

Rudder Type (Enter code from Table 2) 2 Rudder Behind Skeg 1

Rudder Wetted Area AR 50 100.00 m2(Default Value = 0.05*LBP*T) Rudder Behind Stern 2

Shafts Wetted Area ASH 0.00 m2Twin screw balance rudders 3

Shaft Brackets Wetted Area ASHB 0.00 m2

Skeg Wetted Area ASK 0.00 m2

Strut Bossings Wetted Area ASTB 0.00 m2

Hull Bossings Wetted Area AHB 0.00 m2

Stabilizer Fins Wetted Area ASTF 0.00 m2

Dome Wetted Area ADOME 0.00 m2

Bilge Keels Wetted Area ABK 0.00 m2

Particular Value Default Value UnitsBow Thruster Tunnel Opening Diameter ( Enter value

zero if no bow thruster is present) dBT 0 0.00 m

Is the Bow Thruster located in the cylindrical part of

Bulbous Bow? (Write 'Y' for Yes and 'N' for No,'NA' if

no Bow Thruster is present) NA NA

Appendages

Table 2: Rudder Types

Rudder Type

Bow Thruster Tunnel Openings

SHIP RESISTANCE CALCULATION - APPENDAGE INPUTS

Please click the 'Input Speeds' button below to input the various vessel speeds at which you want to calculate resistance

INPUT VESSEL SPEEDS

Doc. No:

Date:

Revision No:

Prepared By:

of 14

Particulars Notation Value Units

Density of Water ρwater 1025 kg/m3

Viscosity of Water ν 0.0000012 m2/s

Length on Waterline L 205 mWetted Surface Area S 7354.32 m2

Vessel Fwd Speed (including Current) V 5.5 m/s

Reynolds Number R 939583333.3

Friction Coefficient (ITTC 1957) CF = 0.075 / [log10 R)-2]2 0.001543

Frictional Resistance RF 17.93 MT


Length of Waterline L 205 m

Breadth B 32 m

Prismatic Coefficient Cp = Cb/CM 0.5833

Longitudinal Center of Buoyancy lcb -1.5375 m

lcb as %age of L -0.7500

Length of Run LR 81.38 m

T/L 0.0488

Stern Type U-shaped with Hogner Stern

Cstern 10

c12 0.5102

c13 1.03

Form Factor 1 + k1 1.1564 MT

Calculation of Frictional Resistance

SHIP RESISTANCE CALCULATION - FRICTIONAL RESISTANCE

1+k1 = c13{0.93 + c12(B/LR)0.92497(0.95-Cp)-0.521448(1-Cp+0.0225lcb)0.6906; where LR/L = 1 - Cp +

0.06 Cp x lcb /(4Cp -1); (LR = Length of Run), Cp = Prismatic Coefficient

c12 = (T/L)0.2228446 for T/L > 0.05, 48.20(T/L - 0.02)2.078 + 0.479948 for 0.02 < T/L < 0.05, and 0.479948 for T/L <

0.02; C13 = 1 + 0.003 Cstern,

where Cstern = 0 for Normal Stern, -10 for V-shaped Sterns and +10 for U-shaped sections with Hogner Stern

Frictional Resistance RF = 1/2 ρwaterSV2 X CF

ρwater = Density of Water, S = Wetted Surface Area, V = Vessel Fwd Speed (including current speed), CF =

Resistance Coefficient as per ITTC 1957 (CF = 0.075 / [log10 R)-2]2 where R = Reynolds Number (R = VL/ν), ν =

Viscosity of Water, L = Waterline Length

Calculation of Form Factor

Form Factor (1 + k1)

Particulars Notation Value Units Appendage Area, S APP 1 + k2 (1 + k2) S APP

Density of Water ρwater 1025 kg/m3 Rudder 50 1.5 75

Viscosity of Water ν 0.0000012 m2/s Shafts 0 4.0 0

Length on Waterline L 205 m Shaft Brackets 0 3.0 0

Total Surface Area of Appendages ΣSAPP 50.00 m2 Skeg 0 2.0 0

Vessel Fwd Speed V 5.5 m/s Strut Bossings 0 3.0 0

Reynolds Number R 939583333.3 Hull Bossings 0 2.0 0

Friction Coefficient (ITTC 1957) CF = 0.075 / [log10 R)-2]2 0.001543 Stabilizer Fins 0 2.8 0

(1 + k2)eq 1.5 Dome 0 2.7 0

Bow Thruster Tunnel Opening Diameter dBT 0.00 m Bilge Keels 0 1.4 0

Bow Thruster Opening Coefficient CBTO 0.000 ΣSAPP 50 Σ(1 + k2)SAPP 75


SHIP RESISTANCE CALCULATION - APPENDAGE RESISTANCE

Calculation of Appendage Resistance

Appendage Resistance RAPP = 1/2 ρwater(ΣSAPP) V2 x (1 + k2)eq x CF + ρwaterV

2 πdBT

2CBTO

ρwater = Density of Water, ΣSAPP = Total Wetted Surface Area of all Appendages , V = Vessel Fwd Speed (including

current speed), CF = Resistance Coefficient as per ITTC 1957 (CF = 0.075 / [log10 R)-2]2 where R = Reynolds Number

(R = VL/ν), ν = Viscosity of Water, L = Waterline Length, (1 + k2) = Appendage Resistance Factor = Σ{(1 + k2)

SAPP}/(ΣSAPP), where (1 + k2) value for different appendages are taken from Table 3, dBT = Diameter of Bow

Thruster Tunnel, CBTO = Coefficient ranging from 0.003 to 0.012 (0.003 being taken for Bow Thruster Tunnel

located in cylindrical part of bulbous bow)



Acceleration due to Gravity g 9.81 m/s2

Length on Waterline L 205 m

Breadth B 32 m

L/B Ratio L/B 6.4063

Draft(mean) T 10 m

Volumetric Displacement DV 36585.34 m3


L3/Dv Ratio L3/Dv 235

Froude Number Fn 0.1226

Angle of Half Entrance iE 12.17 degrees

Bulb Transverse Section Area ABT 13.4848 m2

Transom Transverse Wetted Area AT 16 m2

Prismatic Coefficient Cp 0.5833

Fwd Draft TF 10.00 m

Position of centre of ABT above keel line hB 4.00 m

c7 0.1561

c1 1.4044

c3 0.0121

c2 0.8120

λ 0.6513

c16 1.3809

m1 -2.1251

c15 -1.69385

m2 -0.0007

c5 0.9592

Wave Resistance RW 0.03 MT

Calculation of Wave Resistance

Wave Resistance RW = c1c2c5DV ρwater g exp{m1Fnd + m2 cos(λFn

-2)}

ρwater = Density of Water, g = Acceleration due to gravity, DV = Volumetric Displacement,

Fn = Froude Number = V/√gL where L = Waterline Length, V = Vessel speed + Current Speed ,

c1 = 2223105 c73.78613

(T/B)1.07961

(90-iE)-1.37565

,

c7 = 0.0229577 (B/L)0.33333 when B/L < 0.11, B/L when 0.11 < B/L < 0.25, 0.5 - 0.0625 L/B

when B/L > 0.25, iE = angle of Half entrance (angle of waterline at the bow in degrees)

c2 = exp(-1.89√c3), c3 = 0.56 ABT1.5

/ {BT(0.31√ABT + TF - hB), TF = Fwd Draft, hB = position of

centre of transverse area ABT above keel line

SHIP RESISTANCE CALCULATION - WAVE RESISTANCE






Vessel Fwd Speed V 5.5 m/s


Froude Number based on immersion Fni 0.7458

Measure of emergence of Bow PB 0.5141

Additional Resistance of Bulbous Bow RB 0.00 MT

Calculation of Additional Pressure Resistance of Bulbous Bow near Water Surface

RB = 0.11 exp(-3PB-2) Fni

3ABT1.5 ρwater g/(1 + Fni

2)

ρwater = Density of Water, ABT = Bulb Transverse Section Area, g = Acceleration due to gravity, Fni =

Froude number based on immersion, PB is a measure of emergence of the bow PB = 0.56

√ABT/(TF - 1.5 hB), Fni = V/sqrt{g(TF - hB - 0.25 √ABT) + 0.15 V2}, TF = Forward Draft, hB = position of

centre of transverse Bulb area above keel

SHIP RESISTANCE CALCULATION - Additional Resistance due to Bulbous Bow



Breadth B 32 m

Waterplane area Coefficient CWP 0.75

Transom Transverse Section Area AT 16 m2




Froude Number based on transom immersion FnT 2.3230

c6 0.1071

Additional Resistance of Bulbous Bow RB 2.71 MT

Calculation of Additional Pressure Resistance of Immersed Transom

RTR = 1/2 ρwater V2 AT c6

ρwater = Density of Water, AT = Immersed part of transverse transom area, V = Fwd speed of

Vessel (including current), FnT = Froude number based on transom immersion, FnT =

V/sqrt{2 g AT/(B + B CWP)} , CWP = Waterplane area coefficient

c6 = 0.2(1 - 0.2 FnT) when FnT < 5, 0 when FnT >= 5

SHIP RESISTANCE CALCULATION - Additional Resistance due to Immersed Transom



Waterline Length L 205 m

Breadth B 32 m

Draft(Mean) T 10 m

Block Coefficient CB 0.571646

Wetted Surface Area S 7354.32 m2






Ratio TF/L TF/L 0.0488

c3 0.0121

c2 0.8120

c4 0.0400

CA 0.000352

Model-Ship Correlation Resistance RA 4.10 MT

Calculation of Model-Ship Correlation Resistance

RA = 1/2 ρwater V2 S CA

ρwater = Density of Water,g = Acceleration due to gravity, S = Wetted Surface Area, , V =

Vessel fwd speed (including current), CA = Correlation Allowance Coefficient

CA = 0.006(L+100)-0.16 - 0.00205 + 0.003√(L/7.5) CB4 c2(0.04 - c4), c4 =

TF/L when TF/L <= 0.04, 0.04 when TF/L > 0.04 c2 = exp(-

1.89√c3), c3 = 0.56 ABT1.5 / {BT(0.31√ABT + TF - hB) , TF = Forward Draft, hB = position of centre

of transverse Bulb area above keel, ABT = Bulb Transverse Section Area

SHIP RESISTANCE CALCULATION - Model-Ship Correlation Resistance

Company Name:

Project Name:CARGO FORCES AND ACCLERATION CALCULATION Doc. No:

Date:

Revision No:

Prepared By:

of 14

RF = Frictional Resistance as per ITTC 1957 friction ]formulak1 = Form Factor describing viscous resistance of the Hull Form in relation to RF

RAPP = Resistance of AppendagesRW = Wave Resistance (Wave Making and Wave Breaking Resistance)RB = Additional Pressure Resistance of Bulbous Bow near Water surfaceRTR = Additional Pressure Resistance of Immersed Transom SternRA = Model-Ship Correlation Resistance


Form factor k1 1.1564

Appendage Resistance RAPP 0.18 MT

Wave Resistance RW 0.03 MT

Additional Resistance of Bulbous bow RB 0.00 MT

Additional Resistance of Immersed Transom Stern RTR 2.71 MT

Model-ship Correlation Resistance RA 4.10 MT

27.75 MT

Effective Power, PE = RC x V x g (in kW) PE 1497.36 kW

Final Forces

Effective Power, PE = RC x V x g (in kW)

Results Summary

Total Calm Water Resistance, RC

The total calm water resistance is given by:

RC = RF(1 + k1) + RAPP + RW + RB + RTR + RA

Speed Resistance Effective Power (PE)

(m/s) (MT) (kW)

3 9.06 266.6

4 15.45 606.3

5 23.3 1142.9

5.5 27.75 1497.3

6 32.56 1916.5

7 43.37 2978.2

8 56.21 4411.4

0

10

20

30

40

50

60

0 1 2 3 4 5 6 7 8 9

Resistance vs Speed

Resistance vs Speed

Speed (m/s) --->

Res

ista

nce

(M

T)

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Welcome to the Ship Resistance...

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