Ship Power Prediction - Holtrop and Mennen

The resistance estimation in this calculator is based on the empirical method developed by Holtrop and Mennen. Statistic data from the Netherlands ship model basin has been used by Holtrop and Mennen to develop the method using regression analysis. It has since been further expanded to also cover high-block with low L/B ratio ships and slender navy ships.

Propeller efficiency approximation is caried out using a simplified equation for the Wageningen B-series propeller. Propeller manufactures can typically make propellers with a slightly better efficiency than than what is optained by using B-Series propellers.

Please be aware that Accuracy is best for conventional hull forms and ship types and that this method do not account for all factors affecting the resistance and power requirements. It can be used at a early stage of the design but cannot replace CFD and model testing.

For example see this link

See the article descriping ship form coefficients for detailed description of some the input needed for the power prediction.

Cstern - Aft ship shape factor

The Cstern coefficient is chosen based on the aft ship shape as described in the table below.

Afterbody form Cstern
V-shaped sections -10
Normal sections 0
U-shaped sections with Hogner stern +10

Ship particulars

Property Symbol Unit Value
Waterline length at T L [m]
Beam at the wateline B [m]
Draft T [m]
Displacement at T ∇ [m3]
Longitudinal center of buoyancy forward of 0.5L as a percentage of L lcb [%]
Midship section coefficient CM [-]
Water plane coefficient CW [-]
Wetted surface area - Estimated if 0 is entered S [m3]
Aft ship shape factor (See table above) Cstern [-]
Half angle of entrance - estimated if 0 is entered iE [o]
Max speed for the power prediction Vs,max [knots]
Bulbous Bow
Transverse sectional area of the bulb at the position where the still-water surface intersects the stem ABT [m2]
Position of the centre of the transverse area ABT above the keel line hB [-]
Transom
Immersed part of the transverse area of the transom at zero speed AT [m2]
Appendages
Forward bow thruster diameter dBTO [m]
Appendage Symbol Unit Wet area of the appendage
Rudder behind skeg Sapp [m2]
Rudder behind stern Sapp [m2]
Twin-screw balance rudders Sapp [m2]
Shaft brackets Sapp [m2]
Skeg Sapp [m2]
Strut bossings Sapp [m2]
Hull bossings Sapp [m2]
Shafts Sapp [m2]
Stabilizer fins Sapp [m2]
Dome Sapp [m2]
Bilge keels Sapp [m2]
Input for propulsion factor estimation
Propeller diameter D [m]
Number of propellers
Stern type
Relative rotative efficiency (typically between 0.95 and 1.05) ηR
Shaft efficiency ηS
Service allowance [%]

Results

The results can be transferred to the Optimum B-Series Propeller calculator by pressing here.
Please notice that propeller efficiency will differ as propeller efficiency is estimated by a simplified empirical equation in the Ship Power Prediction - Holtrop and Mennen calculator.

Hull properties

Description Symbol Value unit
Block coefficient Cb 0.572
Prismatic coefficient Cp 0.583
Half angle of entrance iE 12.1 deg
Wetted surface area S 7381 m3
Form factor 1+k 1.156

Resistance

Symbol Description
Vs Ship speed
RT Total resistance - RT=RF(1+k)+RAPP+RW+RB+RTR+RA
RF Frictional resistance according ot the ITTC-1957 friction formula
1+k Form factor describing the viscous resistance of the hull form in realtion to RF
RAPP Resistance of appendages
RW Wave making and wave breaking resistance
RB Additional pressure resistance of bulbous bow near the water surface
RTR Additional pressure resistance of immersed transom stern
RA Model-ship correlation resistance
Vs Fn RF RW RA RAPP RTR RB RT
[knot] [-] [kN] [kN] [kN] [kN] [kN] [kN] [kN]
1.0 0.011 2.12 0.00 0.35 0.02 0.42 0.00 3.24
2.0 0.023 7.69 0.00 1.41 0.08 1.59 0.00 11.97
3.0 0.034 16.37 0.00 3.18 0.17 3.40 0.00 25.67
4.0 0.046 28.01 0.00 5.65 0.29 5.74 0.00 44.04
5.0 0.057 42.49 0.00 8.82 0.44 8.49 0.00 66.87
6.0 0.069 59.76 0.00 12.71 0.62 11.55 0.00 93.94
7.0 0.080 79.74 0.00 17.29 0.83 14.80 0.01 125.09
8.0 0.092 102.40 0.01 22.59 1.07 18.12 0.01 160.13
9.0 0.103 127.68 0.03 28.59 1.33 21.41 0.01 198.92
10.0 0.115 155.57 0.13 35.29 1.62 24.54 0.01 241.37
11.0 0.126 186.01 0.43 42.70 1.94 27.41 0.01 287.47
12.0 0.138 218.99 1.21 50.82 2.28 29.91 0.02 337.32
13.0 0.149 254.49 2.91 59.64 2.66 31.91 0.02 391.25
14.0 0.161 292.47 6.14 69.17 3.05 33.31 0.02 449.70
15.0 0.172 332.93 12.30 79.41 3.47 34.00 0.03 513.96
16.0 0.184 375.84 21.09 90.35 3.92 33.86 0.03 583.59
17.0 0.195 421.18 36.63 101.99 4.39 32.77 0.03 662.56
18.0 0.206 468.94 60.90 114.35 4.89 30.63 0.03 752.73
19.0 0.218 519.10 85.44 127.40 5.42 27.32 0.04 845.52
20.0 0.229 571.65 117.98 141.17 5.96 22.72 0.04 948.51
21.0 0.241 626.57 176.95 155.64 6.54 16.73 0.04 1080.00
22.0 0.252 683.86 269.49 170.81 7.13 9.24 0.04 1247.03
23.0 0.264 743.50 379.09 186.69 7.76 0.12 0.05 1432.94
24.0 0.275 805.48 478.16 203.28 8.40 0.00 0.05 1620.75
25.0 0.287 869.79 556.84 220.57 9.07 0.00 0.05 1791.72

Propulsion factors

Symbol Description
Vs Ship speed
Fn Froude number
Va Advance speed
w Wake fraction
t Thrust deduction factor
ηH Hull efficiency
CTh Thrust loading coefficient
ηo Propeller efficiency in open water
ηT Total efficiency
Vs Fn Va w t ηH CTh ηo ηT
[knot] - [m/s] - - - - - -
1.0 0.011 0.4 0.285 0.175 1.154 1.127 0.646 0.731
2.0 0.023 0.7 0.277 0.175 1.142 1.018 0.657 0.736
3.0 0.034 1.1 0.274 0.175 1.136 0.960 0.664 0.739
4.0 0.046 1.5 0.271 0.175 1.132 0.921 0.668 0.741
5.0 0.057 1.9 0.269 0.175 1.129 0.890 0.672 0.743
6.0 0.069 2.3 0.268 0.175 1.127 0.865 0.675 0.745
7.0 0.080 2.6 0.267 0.175 1.125 0.843 0.677 0.747
8.0 0.092 3.0 0.266 0.175 1.124 0.824 0.679 0.748
9.0 0.103 3.4 0.265 0.175 1.122 0.807 0.681 0.749
10.0 0.115 3.8 0.264 0.175 1.121 0.792 0.683 0.751
11.0 0.126 4.2 0.263 0.175 1.120 0.778 0.685 0.752
12.0 0.138 4.6 0.263 0.175 1.119 0.766 0.686 0.753
13.0 0.149 4.9 0.262 0.175 1.119 0.756 0.688 0.754
14.0 0.161 5.3 0.262 0.175 1.118 0.748 0.689 0.754
15.0 0.172 5.7 0.261 0.175 1.117 0.744 0.689 0.754
16.0 0.184 6.1 0.261 0.175 1.116 0.741 0.689 0.754
17.0 0.195 6.5 0.260 0.175 1.116 0.745 0.689 0.753
18.0 0.206 6.9 0.260 0.175 1.115 0.754 0.688 0.752
19.0 0.218 7.2 0.260 0.175 1.115 0.759 0.687 0.751
20.0 0.229 7.6 0.259 0.175 1.114 0.768 0.686 0.749
21.0 0.241 8.0 0.259 0.175 1.114 0.793 0.683 0.746
22.0 0.252 8.4 0.259 0.175 1.113 0.833 0.678 0.740
23.0 0.264 8.8 0.259 0.175 1.113 0.876 0.673 0.734
24.0 0.275 9.2 0.258 0.175 1.113 0.909 0.670 0.730
25.0 0.287 9.5 0.258 0.175 1.112 0.925 0.668 0.728

Power

Symbol Description
Vs Ship speed
Fn Froude number
T Thrust
PE Effective power
PD Delivered power
PS Shaft power
Vs Fn T PE PD PS
[knot] [-] [kN] [kW] [kW] [kW]
1.0 0.011 3.9 41.7 55.9 57.1
2.0 0.023 14.5 153.9 205.0 209.2
3.0 0.034 31.1 330.1 437.7 446.7
4.0 0.046 53.4 566.5 748.8 764.1
5.0 0.057 81.0 860.0 1133.8 1157.0
6.0 0.069 113.8 1208.2 1589.2 1621.6
7.0 0.080 151.6 1608.7 2111.5 2154.6
8.0 0.092 194.0 2059.4 2697.7 2752.7
9.0 0.103 241.0 2558.4 3345.2 3413.4
10.0 0.115 292.5 3104.3 4052.1 4134.8
11.0 0.126 348.3 3697.1 4818.3 4916.7
12.0 0.138 408.7 4338.3 5646.2 5761.5
13.0 0.149 474.0 5031.8 6541.9 6675.4
14.0 0.161 544.9 5783.6 7513.7 7667.1
15.0 0.172 622.7 6610.1 8586.2 8761.5
16.0 0.184 707.1 7505.6 9750.7 9949.7
17.0 0.195 802.8 8521.3 11082.9 11309.1
18.0 0.206 912.0 9681.0 12618.3 12875.8
19.0 0.218 1024.4 10874.3 14194.0 14483.7
20.0 0.229 1149.2 12198.8 15954.8 16280.4
21.0 0.241 1308.6 13890.0 18253.6 18626.1
22.0 0.252 1510.9 16038.2 21235.8 21669.2
23.0 0.264 1736.2 18429.2 24589.2 25091.0
24.0 0.275 1963.7 20844.7 27980.1 28551.2
25.0 0.287 2170.9 23043.5 31028.1 31661.3