Resistance data of hull form 115

(1)

S ept ember 1912

LABORATORIUM VOOR

SCHEEPSBOUWKUNDE

TECHNISCHE HOGESCHOOL DELFT

RESISTANCE DATA OF HULL FORD" 115

by

Ir. J.J. v.d. Bosch

Report No. 356

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o

Contents Nomenclature List of figures Introduction

4,

Model data Test procedure Test results

7, iscussion of the test results

8.

References

94. Appendix 1 : Summary of measurements 10. Appendix 2 : Table of offsets of model

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1. Nomenclature A A

[A] = E

v2/3 Bc A

B

=-era L cmax

Horizontal projection .of the area bounded by chines. 4114

transom, excluding external spray strips

Breadth over chines at any cross section

Average breadth of area A

Maximum breadth over chines

Span of planing surface, i.e. actual breadth of planing surface measured at main spray point

Incremental resistance coefficient

Speed-displacement coefficient based on volume of displacement

at rest

Centre of gravity

Acceleration due to gravity

L Length of A

1c Wetted length of chiné, measured parallel to the keel

from transom to main spray point

1k Wetted length of keel measured from transom 1 *1

1-

c k Mean wetted length

m 2 [M] . -2 1/3 Resistance RA Incremental resistance S Wetted surface

[s]

= S 42/3

Weight density of water

V Ship or model speed

X Centre of area Ap

G Rise of centre of gravity

a Angle of incidence, i.e. angle between still water surface and keel

(4)

-1-rTh

initial trim atrafgae eee

at

illwialt4e0 7-Sitirorf

]earise angle

:Skip or ;Fade' weigtk

Kinematic viscosity

:Ms density of Waarter

Distancke Of X

front traOSTorn

e`ekt

P'

g_)stance of G from:t'ir:ansom-at. Istera,

G alaeme 1Dase

-aqh1meof 0,e

aispioc

ement of 'Male

sia-

v.,(04

- A

(5)

2. List of figures K_J

Figure 1. Lines and form characteristics of the hull

Figure 2. Resistance-weight ratio of the standard ship and angle

of attack

Figure 3. Wetted surface and mean wetted length ratio's

Figure 4. Wetted length ratio's and rise of centre of gravity Figure 5. Resistanceweight ratio as a function of A and

FnV

3. Introduction

The tested model was one of a series of three

.the numbers114, 115 and 116.

The aim of the test series was to compare the three hull forms with regard to the resistance in smooth water and the behaviour in irregular head seas

in the speed range betwee Fn7 = 2 and F1-17 = L. This was done in order to develop a hull form with a good overall performance at sea which could

function as a parent for a systematic series.

In this report the resistance data of hull form 1-5 in sea water are

given for displacements of up to 300 metric tons. For the information about the other test results the reader is,referred to the references [1]

[2] and [3] .

The tests, although being a part of the research program of-the Ship-building Laboratory of the University of Technology, were carried out at the Netherlands Ship Model Basin under the responsibility of the

Netherlands Ship Research Centre, TNO.

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4 5 6 7 8

4.

Modeldata 9 o

The hullform is shown in figure 1.

2

The main particulars of the model 115 are given in the following table

3 4 5 6 7 A

.93312

m2 8 9 Bcmax

0.54

0

0.432

2 cm 3 4 L

2.16

5 6 4 7 /Bcmax 8 9 L/Bcm 5 3 :5 6 7 9 0.1 2 3 4 5 6 7 8 9 o 2 3 4 6 7 8 9 O 2 3 4 5 6 7 8 9 AX AG KG [A] Lml Test 1

.04665

1.008

0.864 .18

7.2

6 m3 m m m

4

Test 2

.06133

1.008

0.864 .197

6

5.477

m3 m

(7)

"ar

5. Test procedure

The model was tested at the loading conditions stated in the preceding section, over a speed range which correspOnded to the range of Froude

numbers from FnV = 1.6 to FnV = 4.0.

The model was attached to the towing carriage in its centre of gravity by an airlubricated support, which allowed the model to Ditch, heave

and roll freely.

The following parameters were measured

the modelspeed, which equalled the carriage speed the resistance, measured by a strain-gauge dynamometer

the rise of the centre of gravity, measured by a potentiometer the trim angle, measured by a gyroscope

the form and magnitude of the area wetted by'solid water were

determined from visual observation.

6.

Test results'

The actual results are given in the appendix 1. The faired results are given in the figures 2 to 5. InlIgure 2 the resistance/weight ratio is given for a standard displacement of A = 16000 kg in seawater with a weight density of 1025 kg/m3 and a temperature of 15oC, using the I.T.T.C.

1957 extrapolator4without roughness allowance. When it is desired to take into account this additional resistance, use can be made of the curve in the lower part of the figure where the additional resistance/weight ratio RA is given forsan incremental resistance coefficient

_{_}

0A = 0.0002.

This curve holds for any value of the ship's displacement; for

12 CA.V

S

= 0.0001.F 2. S

pgV ny

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In figure 3 the wetted surface and the mean length of the wetted

surface are

given, reduced to nondimensional coefficients.

In figure 4 the wetted length at the keel and at the chine are giyen and the

rise of the centre of gravity, also reduced to nondimensional coefficients.

In figure 5 the resistance/weight ratio is

given for displacements of

1

to

250 metric tons. The resistance has been computed for seawater with w = 1025

kg/m3 and t = 15o C. Use has been made of the I.T.T.C. 1957

e4.mtrapolator without

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1

2 3

5

6

Discussion of test results

There are no exceptional things to report.

The resistance and trim curves are smooth without accessive humps. The resistance characteristics are good, considering the high deadrise

of the hull.

References

"Resistance data of hull form 114"

Shipbuilding Laboratory of the University of Technology, Delft.

Report no.

355.

"Resistance data of hull form 116"

Report no. ₃₅₇

[3)

"Comparative model tests of three planing hulls in calm water and

irregular head waves"

Report no.

358.

7 8

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3 4 5 6 7 8 9 Appendix I o

2 Results of resistance test with model 115 in still water

3 4 5 Test 1 6 Displacement

46.65 am3

7 8 Temperature

21.8

centigrade 9 o

2 model rise of trim model wetted wetted wetted

3 speed centre of angle resistance length of length of surface

4 gravity keel chine

5 6 m/sec cm degrees kg cm cm m2 7 8 9

3.04 -

2.77

5.15

202 194

1.070

o

_3.73

1.21

3.27

6.04 -

-

-.1 2

4.48

2.24

3.47

6.75 -

-

-3

4.41

2.19

3.45

6.76 -

-

-4 5

5.17

2.40

3.47

7.47 -

-

-6

5.21

2.60

3.43 _7.50

-

-7

_5.94

_2.88

_3.35

8.57

8 _ _ _ 9

5.84

2.88

3.23

8.44

_

_-

_ o 1

6.69

3.39

3.10

9.57 -

-

-2

7.52

4.14

2.78

11.00 -

-

-3 4

4.50

_

-

194.0

170.0 .995

5

5.20 -

_

-

191.5

172.0 .970

6 7

7.54

_ _

-

_186.0

_157.5

_.940

8 9 o 1 2 3 4 5 6 7 8 9 o 2 3 4 5 6 7 8 9

8-o

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2 3 4 5 6 7 8 9 o Test 2 1 Displacement

61.33 dm3

2 Temperature

21.8

centigrade 3 4 5 6 rr 8 9 0 1 2

Results of resistance test with model 115 in still water

3 4 5 7 8 9 o 1 2 3 4 5 o 1 2 3 4 5 D 7 8 9 D 1 2 3 4 5 5 1 id 9 o 1 2 3 J, 5 5 7 3 9

-9

3.11 .34

3.62

3.98

1.80

4.28

8.76

_ _ _

4.67

3.20

4.17

9.17 -

-

-5.58

3.91

3.42

9.71 -

-

-6.22

4.43

3.30

10.29

190.5

143.0 .905

6.97

5.18

3.50

11.06 -

_ _

7.82

5.35

2.82

12.02 -

-

-3.08

_

-

_204.5

_198.5

_1.125

3.92 -

-

199.5

177.5

2.085

4.64 -

-

195.0

163.0 .960

7.85 -

-

187.5

139.0 .900

model rise of trim model wetted wetted wetted

speed m /sec centre of gravity cm angle degrees resistance kg length of keel cm length of chine cm surface 2 m

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4 5 6 7

-8 9 o Appendix II

Table of offsets of model 115

4 ord 0 ord 2 ord 4 ord 6 ord 7 ord 8 ord 9 ord 10

5 6 mm MM M171 171M MM 1/1171 MM 111M 7 8 o

_2.7

2.7

9 o 4 102.8 102.8 102.8

99.3

88.4

61.9

1 8 183.0 190.5 189.0 174.4 153.1 112.7 37.1 2 3 12 199.9

236.9

261.0

236.5

206.7

156.1

71.0

4 16

212.0

252.3

280.5

276.8

251.6

195.2 103.7 5 6 20 24

221.9

264.1 231.1

275.2

295.1

307.8

295.7

311.8

274.9

294.6

225.9

135.0

251.3

164.8

21.3

I 9 28

239.6

285.2

319.9

326.1

311.6

273.8

194.4 54.3 2 Deckline Chine 3

4 ord Beam Height ord Beam Height

5 6 7 o 240

300.0

o 180

75.0

8 2 289

315.6

2 225.1 97.1 9 o 4

328.4

331.2

4

260.3

119.0 6

_341.4

_346.8

6

267.3

142.3 2 3 7

331.4

354.6

7

249.0

155.8 8

_304.6

_362.4

8

206.3

171.8 5 6 9

249.7

370.2

9 128.7 191.4

lo

147.9

378.0

10

2.7

216.0

9

o Keel and 3tem

2 ord Beam Height

3 4 6

2.7

o 5 7

2.7

.1 6 7 8

2.7

3.7

8 9

2.7

41.6

9 o

lo

2.7

216.0

2 3 5 6 7 8 9

-

10 o

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46.67 % L 0 8 st. 3-10 DETAIL SPRAYSTRIPS

SCALE 1 : 5 FOR A a 15 TON

Fig.1

Lines and formoharocteristies

of the hull of model 115.

A 120 100 80 60 .4,-;'''

NI

di 60 50 40 90

Illii4

-91-Ht. MEAN

_...allim

BUTTOCK% 4

..

40 20, %

I

L/10

A

116k

1

20 CENTE OF Ap PP-20 30 40 50 60 70 80 90 1'

(14)

21E4R. etc

4

7 .2

o

FatV

fig. 2 Resistance-weight ratio of the standard ship and angle of attack

Restsrafice toieRsersn

IN SEAlorret

ceE-FFILIEWM

AO 48 : hioao lei

hIbiN4 7746 .17Tc., '357

lairmour

Re1aNNE46-Atom:vim.

6 14] .--.

--- ---

[Pi ---. 72

1.2

MaDEL. 1/5 % 4

...

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fig. 4 Wetted length ratio's and risë of centre of gravity

.10

741

'05

(16)

R.

lo

60

4 .pey,g7ONS

fig. 5 A Resistance-weight ratio as a function of A and F _LA)

_1.2

(17)

8

3 o

11111 FAV

fig. 3 Wetted surface and mean wetted length ratio's

-

. _

CS 7

bvicg

ikTr.72

/*JD& #5

17* 2

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.2o

3o

4-0

--m.4 PlErR le TOMS

fig. 5 B Resistance-weight ratio as a function of A and .F tAl= 6

nv