TAKE HOME EXAM

HAMBATAN DAN PROPULSI KAPAL

I. UKURAN UTAMA DAN BESARAN

LWL = 127.92 m
LPP = 123.00 m
B= 20.20 m
H= 11.50 m
T= 8.80 m
Vsea = 14.0 knots = 7.2016 m/s
Cb = 0.7100 (block coefficient)
Cp = 0.7200 (prismatic coefficient)
Cm = 0.9850 (midship coefficient)
Cwp = 0.7992 (waterplane coefficient)
= 16548.35 ton
WSA = 3285.61 m2
= 1025 kg/m3
= 1.025 ton/m3
V= 16144.73 m3
LCB = 0.047 % 0.06 m
g= 9.81 m/s

vt
Fn
g LWL
= 0.203

II. PERHITUNGAN HAMBATAN

METODE HOLTROP

Rn ( Reynold Number )
Rn =
V s
L w l.
v

Rn= 780702264

Cfo ( Friction Coefficient )

Cfo =
0.075
(log Rn 2) 2
 Cf = 0.0015787361

Form Factor of the Hull

1 + K1 =
1 .0 6 8 1 0 .4 6 1 1 0.1 2 1 6 0.3 6 4 9
L3
0,93 0, 487.c
B
.
T
.
L
. . 1 C
L L L R

c= 1+0.011 cstern
cstern = 0 ( karena normal section shape )
= 1

B/L= 0.1579112

T/L= 0.068793

LR/L =
0.06 C P . LCB
1 CP
4C P 1
0.2813284

LWL^3= 129.65358

1+k1= 1.2233

V^1/3 / 0.197578

Resistance of Appendages
Wetted Surface Area

ABT= 10%*B*T*Cm cross sectional area of bulb in FP

0 Karena tidak ada bulb

S =L 2T B C M 0.5 (0.4530 0.4425C B 0.2862C M 0.003467B 0.3696CW P ) 2.38 ABT

T CB
s= 3708.2152

S Rudder
= C1 . C 2 . C 3 . C 4 .
1.75 .L.T
100

C1 = 2223105C43.7861(T/B)1.0796(90-iE)(-1.3757)
 C4 = B/L
0.158

iE = 125.67(B/L) - 162.25Cp2 + 234.32Cp3 + 0.1551(LCB + (6.8(Ta-Tf)/T))3

23.194

C1 = 2.58

C2 = e(-1.89) AbtRb
BT(Rb+i)
= 1.00000 (tanpa bulbous bow)

C3 = koefisien pengaruh bentuk transom stern terhadap hambatan

C3 = 1 - 0,8 x AT
B x T x Cm
dimana ;
AT = 0 m
C3 = 1

C5 = koefisien dengan fungsi koefisien prismatik (Cp)

dimana ;
Cp = 0.720
Untuk (Cp 0.8), maka C5 dihitung sebagai berikut :
C5 = 8.0798Cp 13.8673Cp2 + 6.9844Cp3
C5 = 1.236

C6 = koefisien pengaruh terhadap harga L3/V

dimana ;
L3/V = 129.65
= -1.694

S = 1.75 . L . T
Rudder C1 . C 2 . C 3 . C 4 .
100

= 16.068634

m1 = 0.01404 (L/T) - 1.7525 (V1/3/L) - 4.7932 (B/L) - C5

-2.1346258

m2 = C6 x 0.4 x e-0.034 x Fn^(-3.29)

= -0.001100127
 = 1.446Cp - 0.03 L/B
0.8511398

W = gV kN
162339.32

d= -0.9

RW C1C2C3 em1 x Fn^d + m2 cos (Fn^-2)

W 0.0003337935

RW= 54.187811

CA 0.006
= (LWL + 100 )-0.16-0.00205
= 0.0004671324

WSA = L(2T+B)Cm0.5(0.4530+0.4425Cb-0.2863Cm-0.003467(B/T)+0.3696Cwp) + 2.38(ABT/Cb)

3707.6654 m

Sbilge = luasan bilge keels

= 0.6 Cb L (0.18/(Cb-0.2))
= 76.933 m

Sapp = Skemudi + Sbilge

= 93.001

Stotal = WSA + Sapp

3800.667

R
R T 1 V 2 S tot C F 1 k C A W W
2 W
296.47564 Kn

Rt dinas= RT+10%
326.12321

Wake Fraction
w 0.5cb - 0.05
0.305
k 0.7 - 0.8
0.8

t k*w
0.244

Forces

Towing Resistance
Rt (1-t)T*THP
KN

Thrust Force
T Rt/(1-t)
392.1635

Propulsive Coefficient
PC= h*o*r
0.64893 kW

EHP/PC 4920.737

Power Effective

2.348609 kW

Thrust Power Depends on open water test Efficiency

PT= PE (1 )/(1 t)
2.348609 Kw

PD ( Input Power Delivered to Propeller )

PD = PT/(o r)
3.619202 Kw

Shaft Power
Ps =
3.807282 Kw

Brake Power

3.904504
PB = 3.904504 kW
= 5.23594 HP ( Normal Continous Rating )

PB = 4.49018 kW
= 6.021331 HP ( Max Continous rating )

Velocities

Ship's Speed
Vs 7.2016 m/s

Arriving water velocity to propeller

Va (1-w)Vs
5.005112 m/s

Effective wake velocity

Vw V-Va
2.196488

Wake Friction Coefficient

W V-Va
V
6.5066

Hull efficiency Stern tube and bearing efficiency

h (1-t)/(1-w) s 0.98 for machinery aft
1 b 0.97 for machinery amidship

Relative Rotative Efficiency

Rr = 1.05 1.02 r 1.05

Open Water Efficiency

Wageningen B-Series
o = 0.669 0.50 0 0.669

Rotative Efficiency
r = 0.97 0.97 r 1.07

Effective Horse Power

EHP Rt dinas x Vs
2348.6088923 kw 1HP= 0.7355
 3193.2139936 HP
Thrust Horse Power
THP EHP/h
2348.6088923 KW 3193.214 HP

Delivery Horse Power

DHP EHP/PC
3619.2022133 KW 4920.737 HP

SHAFT HORSE POWER

Kapal dengan kamar mesin di belakang
SHP DHP/0.98
3693.063483 KW 5021.16 HP

BREAK HORSE POWER

BHP = SHP / t
( 1-li )
li = 0.010 for each gear reduction
li = 0.005 for the trusth bearing
li = 0.010 for a reversing gear path

t = ( 1 - 0,010 ) x ( 1 - 0,005 ) x ( 1 - 0,010 )

0.9751
BHP = SHP / 0,975
= 3787.757418 kw 5149.9081148 HP

BHPScr = SHP/hg
3768.432126 kw 5123.633073 HP

BHP MCR= bhpscr +15%bhpscr

4333.696944 kw 5892.1780345 HP

Pemilihan Engine
Type Engine = MAN B&W S35MC Mark 7
Jumlah silind = 6
Bore = 350 mm
SFOC = 178 g/kwh
STROKE = 1400 mm
STROKE = 2
Cylinder Pitc = 600 mm
BHP = 6060 KW
SFOC Charg = 131 g/bph
Dry Mass = 75 ton
Speed = 173 rpm
Power Sourc = dual-fuel, gas, diesel
Power min =
Power Max = 4440 Kw (6036.71 hp)

PERHITUNGAN ENGINE

BHP MCR 4440 KW

BHP SCR BHP MCR - 15% x BHPScr

 3874.7351812 KW

SHP 0.98 x BHP SCR

3797.2404775 KW

DHP SHP x 0.98

3721.295668 KW

RPM main engine : 173 rpm

RPM propeller : 173 rpm
DHP : 3721.29567 KW
Va : 5.0051 m/s
: 9.7300 knot

0. 5
N propeller xPd
B p1 2. 5
Va
35.736424
0,1739.Bp 1.0395733
1.04

Type
0.1739 (BP)1/2 P/Do 1/Jo o o
Propeller
B3-35 1.04 0.679 2.375 240.51 0.585
B3-50 1.04 0.677 2.356 238.58 0.569
B3-65 1.04 0.708 2.3 232.91 0.545
B3-80 1.04 0.772 2.2 222.78 0.522
B4-40 1.04 0.716 2.26 228.86 0.563
B4-55 1.04 0.71 2.27 229.87 0.558
B4-70 1.04 0.74 2.245 227.34 0.548
B4-85 1.04 0.78 2.16 218.73 0.535
B4-100 1.04 0.845 2.5 253.16 0.545
B5-45 1.04 0.767 2.167 219.44 0.55
B5-60 1.04 0.752 2.195 222.2785 0.554
B5-75 1.04 0.761 2.174 220.1519 0.549
B5-90 1.04 0.799 2.138 216.5063 0.539
B5-105 1.04 0.846 2.681 271.4937 0.525

Calculation of Do, Db, b, P/Db, b

Do (ft) = Vaxo
N
Db (ft) = 0.96 x Do (single screw)
 Db (ft) = 0.98 x Do (twin screw)
b = DbxN
Va
1/Jb = 0.009875 x b

Type single screw

b 1/Jb P/Db b
Propeller Do (ft) Db (ft)
B3-35 13.52674325 12.9856735202 230.886076 2.28 0.875 0.593
B3-50 13.418529304 12.881788132 229.038987 2.26176 0.765 0.58
B3-65 13.099582937 12.5755996195 223.594937 2.208 0.89 0.556
B3-80 12.530035853 12.0288344187 213.873418 2.112 0.98 0.533
B4-40 12.871764103 12.3568935392 219.706329 2.1696 0.8 0.575
B4-55 12.928718812 12.4115700593 220.678481 2.1792 0.856 0.571
B4-70 12.786332041 12.2748787591 218.248101 2.1552 0.866 0.46
B4-85 12.302217019 11.8101283383 209.98481 2.0736 0.766 0.557
B4-100 14.238677105 13.6691300212 243.037975 2.4 0.876 0.4325
B5-45 12.342085315 11.8484019024 210.665316 2.08032 0.877 0.569
B5-60 12.501558499 12.0014961586 213.387342 2.1072 0.765 0.562
B5-75 12.381953611 11.8866754665 211.345823 2.08704 0.787 0.572
B5-90 12.176916661 11.6898399941 207.846076 2.05248 0.76 0.557
B5-105 15.269557328 14.6587750348 260.633924 2.57376 0.88 0.462

Diameter of propeller is determined by

D = 0,7T
D = 6.16 m

Dmax = D - 0,08D
= 5.6672 m
Type D
Db (ft) Db (m) D dipakai (ft) Db < Dmax
Propeller max (m)
B3-35 12.98567352 3.96 5.6672 18.5931759 excelent
B3-50 12.881788132 3.93 5.6672 18.5931759 excelent
B3-65 12.57559962 3.83 5.6672 18.5931759 excelent
B3-80 12.028834419 3.67 5.6672 18.5931759 excelent
B4-40 12.356893539 3.77 5.6672 18.5931759 excelent
B4-55 12.411570059 3.78 5.6672 18.5931759 excelent
B4-70 12.274878759 3.74 5.6672 18.5931759 excelent
B4-85 11.810128338 3.60 5.6672 18.5931759 excelent
B4-100 13.669130021 4.17 5.6672 18.5931759 excelent
B5-45 11.848401902 3.61 5.6672 18.5931759 excelent
B5-60 12.001496159 3.66 5.6672 18.5931759 excelent
B5-75 11.886675466 3.62 5.6672 18.5931759 excelent
B5-90 11.689839994 3.56 5.6672 18.5931759 excelent
B5-105 14.658775035 4.47 5.6672 18.5931759 excelent
Ap : Projected Area from Propeller
= AD x ( 1,067 -( 0,229[P/Db])
(Principles naval architecture, hal 182, pers 59)
VR2 = Va + ( 0,7 x p x n x D)
2 2

(Harvald,SV. Tahanan dan propulsi kapal, hal 199)

: sea water density (1,025 ton/m3)
Ao : x x Db2

Type Ae or AD
Ae/Ao Ao (ft2) Ap (ft2) Va (m/s) n (rps)
Propeller (ft2)
B3-35 0.35 132.3727576661 46.3304652 40.15 5.0051 3
B3-50 0.5 130.2632654 65.1316327 58.09 5.0051 3
B3-65 0.65 124.1443790456 80.6938464 69.65 5.0051 3
B3-80 0.8 113.5838931154 90.8671145 76.56 5.0051 3
B4-40 0.4 119.8638620819 47.9455448 42.37 5.0051 3
B4-55 0.55 120.9269509988 66.509823 57.93 5.0051 3
B4-70 0.7 118.2780291114 82.7946204 71.92 5.0051 3
B4-85 0.85 109.4911181238 93.0674504 82.98 5.0051 3
B4-100 1 146.6734156965 146.673416 127.08 5.0051 3
B5-45 0.45 110.2019326979 49.5908697 42.95 5.0051 3
B5-60 0.6 113.0681893858 67.8409136 60.50 5.0051 3
B5-75 0.75 110.9150471111 83.1862853 73.77 5.0051 3
B5-90 0.9 107.2721018847 96.5448917 86.21 5.0051 3
B5-105 1.05 168.6805531329 177.114581 153.29 5.0051 3

VR2 = Va2 + ( 0,7 x p x n x D)2

Type C
Vr2 calculation c 0.7R Kavitasi ?
Propeller diagram
B3-35 654.27324 0.3448592929 0.287373 0.136251 yes
B3-50 644.24596 0.2420920488 0.291846 0.137918 yes
B3-65 615.16038 0.211428629 0.305645 0.142903 yes
B3-80 564.96205 0.2094410502 0.332804 0.152088 yes
B4-40 594.81332 0.3594314079 0.316101 0.146532 yes
B4-55 599.86662 0.2607067583 0.313438 0.14562 yes
B4-70 587.27521 0.2144827446 0.320159 0.147909 yes
B4-85 545.50741 0.2001415486 0.344673 0.155869 yes
B4-100 722.25015 0.0987059846 0.260325 0.125586 NO
B5-45 548.88621 0.3842494846 0.342552 0.155203 yes
B5-60 562.5107 0.2661961187 0.334254 0.152557 yes
B5-75 552.27593 0.222370258 0.340449 0.154539 yes
B5-90 534.95952 0.1964340389 0.35147 0.157976 yes
B5-105 826.85911 0.0714753185 0.227389 0.11099 NO
 0.3 6 4 9
L3
. 1 C
p
0.6 0 4 2

ABT
6CW P ) 2.38
CB
mal Continous Rating )

Continous rating )

efficiency
or machinery aft
or machinery amidship
 #DIV/0!
#DIV/0!
1.04 1.04
 calculation of thrust coefficient
tC = (T/ Ap) / ( 1/2 x r x VR2)
= T / (1/2 x x Ap x VR2)
T = EHP / ((1-t) x Vs x 0.514444)
= 431.34301

Calculation of cavitation
determine the number of cavitation by using this formula;

0,7R = (1,882+19,62(h))/Va2+4,836n2D2
(Principles naval architecture, hal 182, pers 61)
where :
h : Distance between draft and the propeller center line
= T (0,04 x T) (0,35 x T)
= 5.37 m