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Perhitungan Perancangan Propeller Menggunakan Dasar Princhipal Naval Architechture II I. UKURAN UTAMA DAN BESARAN LWL = 38,454 m {=L ; PNA II, p.91} LPP = 37,7 m B= 7,3 m H= 3,2 m T= 2,6 m vservice = 11,70 kn = 6,02 m/s vtrial = 12,87 kn = 6,62 m/s d= 0,57 {block coefficient, Cb} j= 0,69 {prismatic ...

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Perhitungan Perancangan Propeller Menggunakan Dasar Princhipal Naval Architechture II I. UKURAN UTAMA DAN BESARAN LWL = LPP = B= H= T= vservice = vtrial = d= j= Cm = Cw = D= LCB =

Fn =

= r=

38,454 37,7 7,3 3,2 2,6 11,70 12,87 0,57 0,69 0,820 0,783

m {=L ; PNA II, p.91} m m m m kn = 6,02 m/s kn = 6,62 m/s {block coefficient, Cb} {prismatic coefficient, Cp} {midship coefficient} {waterplane coefficient}

419,73 ton = 0,152 m

vt g ´ LWL

3 409,493 m

{data-data: TR II Kurva Hidrostatik & Bonjean}

6,62 9,81 𝑋 38,454

0,341 3 1025 kg/m

Referensi: Harvald, Resistance and Propulsion of Ships, John Wiley and Sons, NY, 1985. Lewis, Edward V., Principles of Naval Architecture Volume II: Resistance, Propulsion, and Vibration, The Society of Naval Architects and Marine Engineers, NJ, 1988. Van Lammeren, W.P.A., Troost, L., Koning, J.G., Resistance, Propulsion, and Steering of Ships: A Manual for Designing Hull Forms, Propellers, and Rudders, The Technical Publishing Company H. Stam-Haarlem, 1948

Laporan Praktikum Propulsi Kapal Fishing Vessel Hidayat

II. PERHITUNGAN DAYA MESIN INDUK Untuk perhitungan daya mesin induk digunakan metode Holtrop. Referensi: Lewis, Edward V., Principles of Naval Architecture, Volume II Resistance, Propulsion, and Vibration, The Society of Naval Architects and Marine Engineers, NJ, 1988.

A. Perhitungan (Rw / W) Fn =

0,341 {lihat: I.Ukuran Utama dan Besaran}

Untuk Fn ≤ 0.4 maka: A.1 Koefisien: C1 C1 = 2,223,105 x C4 3.7861 x (T/B)1.0796 x (90 - iE )-1.3757 (PNA II, p. 92)

=

0,190

Untuk 0,11 ≤B/L ≤ 0,25 maka C4= B/L C4 =

0,190

iE = ½ (sudut masuk garis air muatan penuh) dalam derajat =

10,5

o

{data: TR I Rencana Garis; sudut masuk = 21o } Maka: 3.7861 x (3,2/7,3)1.0796 x (90 - 10,5)-1.3757 C1 = 2,223,105 x (0.19)

=

3,284

A.2 Koefisien: C2 C2 = koefisien pengaruh bulbous bow = 1,000 {untuk kapal tanpa bulbous bow } A.3 Koefisien: C3 C3 = koefisien pengaruh bentuk transom stern terhadap tahanan gelombang. = 1 - 0.8 x A T / (BxTxCm)

AT =

{PNA II, p. 93}

2 0,199 m {area of transom ; data: TR I Rencana Garis}

= 1 - 0.8 x 0,199 / (7,3x3,2x0.82) =

0,990

A.4 Parameter: d d= -0,9 {tetapan untuk Fn ≤ 0.4} A.5 Koefisien: m1 m1 = 0.01404 L/T - 1.7525 V 1/3 /L - 4.7932 B/L - C5

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C5 = 8.0798 Cp - 13.8673 Cp 2 + 6.9844 Cp 3 = 8.0798 x 0.69 - 13.8673 x 0.69 + 6.9844 x 0.69 = 0,826

{untuk Cp ≤ 0.8}

Maka: 1/3 m1 = {0.01404 x 38,454/2,6} - {1.7525 (409,493) /27.03} - {4.7932 x 7,3/38,454} - 0.706 = -1,867

A.6 Koefisien: m2 -3.29

m 2 = C6 ´ 0.4 ´ e - 0.084 ´ Fn

L3 /V = 38,454/409,493 =

138,860 -1,694 {untuk L3 /V ≤ 512}

C6 = Maka:

m 2 = - 1 .694 ´ 0 .4 ´ e =

- 0 .084 ´ 0 .273 - 3 .29

-3,735E-02

A.7 Koefisien: l L/B = 38,454/7,3 = 5,268 l = 1.446Cp - 0.03 L/B

{untuk L/B ≤ 12}

= 1.466 x 0.69 - 0.03 x 38,454/7,3 = 0,854

Maka nilai Rw / W adalah sbb.: W = rgV x 10-3 kN {PNA II, p. 64-65} -3 = 1025 x 9.81 x 409,493 x 10

=

{r air laut = 1025 kg/m3 ; g =9.81 kg.m/s 2 } 4.117,55 kN

d Rw = C1C2C3 ´ e m1 ´ Fn + m2 cos (lFn - 2 ) W = 3,284 x 1 x 0,99 x e + -3,735E-02 cos 0,707 x

=

5,630E-03

B. Perhitungan (1 + k) B.1 Koefisien: (1+k 1 ) 1+k 1 = 0.93 + 0.4871c (B/L)1.0681 (T/L)0.4611 (L/LR )0.1216 (L3 /V)0.3649 (1-Cp)-0.6042 {PNA II, p. 91} c = koefisien bentuk afterbody = 1 + 0.011cstern cstern = 0 (untuk bentuk potongan stern normal) Maka:

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c=

1,000

LR / L = 1 - Cp + 0.06Cp x LCB / (4Cp-1) = 1 - 0.69 + 0.06 x 0.69 (0.152) / (4 x 0.69 -1) = 0,314 Maka : 1.0681 (2,6/38,454)0.4611 (38,454 /0.414)0.1216 (138,86)0.3649 (1-0.69)-0.6042 1+k 1 = 0.93+0.4871x1x(7,3 / 38,454 )

=

1,096

B.2 Koefisien: (1+k 2 ) Koefisien ini merupakan koefisien akibat pengaruh tonjolan pada lambung kapal di bawah permukaan garis air. 1+k 2 =

1,500 {PNA II, Table 25 p. 92; for rudder of single screw ship only}

Maka nilai (1+k) : 1+k = (1 + k1 ) + [(1 + k2 ) - (1 + k1 )] x Stonjolan / Stotal {PNA II, p.92} Stonjolan =

2 2,06 m {data: TR IV Rencana Umum; Bab II, luasan daun kemudi}

2 S = 1713,95 m {data: TR II Kurva Hidrostatik & Bonjean; Tabel H}

Stotal = S + Stonjolan = 2.06 + 1713.95 2 = 1716,010 m

1+k = (1.073) + [ (1.5) - (1.073) ] x 12.4386 / 735.831 =

1,097

C. Perhitungan Tahanan Gesek, CF Untuk nilai tahanan gesek ini, diambil dari perhitungan dengan menggunakan metode Harvald. CF =

1,824E-03 {TR IV Rencana Umum; II.1.a Perhitungan Tahanan Gesek; Harvald(1985), eq. [5.5.7]}

D. Perhitungan model-ship allowance coefficient, CA T/ LWL = 2,6 / 38,454 = 0,068 CA = 0.006 (LWL + 100)-0.16 - 0.00205 -0.16

= 0.006 (38,454 + 100) = 6,761E-04

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- 0.00205

{untuk T/LWL ≥ 0.04; PNA II, p.93}

E. Tahanan Total, RT R R T = 1 rV 2 Stot [C F (1 + k ) + C A ] + W W 2 W

=

1,032E+05 N

F. Effective Horse Power, EHP EHP = RTV

{PNA II, p.153; Harvald(1985), eq. [9.6.3]}

= RT x v trial = =

683056,7966 Watt 928,698 HP

{ 1 HP (metric ) = 735,499 Watt }

Sesuai dengan rute pelayaran, EHP ditambah EHP = 924,855 x 1.2 = 1114,438 HP

20%

{TR IV R.U., rute 5000 SEA MILES}

G. Shaft Horse Power, SHP {Harvald(1985), eq. [9.6.15]} EHP SHP =

hT

hT = total efficiency = hH . hB . hS hH = efisiensi badan kapal =

1,13

{Harvald (1985), Gbr. 6.4.26; data TR IV Rencana Umum}

hB = efisiensi baling-baling di belakang kapal =

0,798

{Harvald (1985), Gbr. 6.3.11; data TR IV Rencana Umum}

hS = efisiensi poros =

0,700

{Harvald (1985); data TR IV Rencana Umum}

Maka: hT = 1.2116 x 0.75 x 0.97 = 0,631

SHP =

1765,536 HP 201951,794

H. Breake Horse Power (BHP) Kerugian daya untuk posisi mesin di belakang = BHP = SHP x 1,03 =

1818,502 HP

208010,348 (watt) I. Pemilihan Mesin Utama

5747,7 242955,609

Mesin utama yang digunakan adalah:

5|

Tipe : Kecepatan : Daya :

Caterpillar 3516 B 1800 rpm 2000 HP

3%

{PNA II, p. 202}

III. PERHITUNGAN DIAMETER PROPELER, Bp-d DIAGRAM Koefisien propeler Taylor:

Bp =

d =

n ( PD )0.5

(Va )2.5

{PNA II, p.191}

nD Va n = revolution per minute (rpm) of propeller PD = delivered power at propeller = daya mesin induk = 2000 HP Va = speed of advance D = diameter propeler = 1,69 m {data TR I Rencana Garis; D ≈ 0.65 x T}

A. Perhitungan Va Va = V ( 1 - w)

w = 0.10 + 4.5

{PNA II, p.146}

1æ E D ö + ç - - k' K ÷ 7 - 6Cvp 2.8 -1.8C p 2 è T B ø

(

CvpC p B L

)(

)

Cvp = vertical prismatic coefficient = Cb / Cw = = Cp = = B= = L= = T= = E=

0.57 / 0.783 0,728 prismatic coefficient 0,69 ship's breadth 7,3 m ship's length 38,454 m {LWL } ship's draft 2,6 m tinggi poros propeler dari baseline

= 1,161 m {data TR I Rencana Garis; E ≈ 0.4 x T} K = the rake angle of propeller blades, radians = 10 o {dirancang sendiri} = 0,175 rad k' = koefisien = 0,3 {bentuk stern normal}

W =

0,286

Maka : Va = Vt ( 1 - w) = 6,62 ( 1 - 0.268 ) = 4,727 m/s = 9,189 knots

6|

{PNA II, p.159 eq. 46}...