The effect of shape of afterbody on propulsion

TH _{EFFECT OF SHAPE OF AFTERBODY ON PROPULSION.}

BY

J.]). VAN MANEN AND

_{J. KAÌ1PS.}

Publication nr. 175 of the Netherlands Ship Model

_Basin.

NEDERLAPIDSCH SCHEEPSBOUWKUNDIG BLZ.

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J.D. VAN MAIN AND

J. KA}4PS.

Publication

, 175

_{of the Netherlands Ship Model Basin.}

Introduction.

The inequality of the flow at the location of the ship propeller

forms a complex of problems, which troubles many scientists already

for years

.

[i

_{J L23 [3}

The recent development in ship size and engine

power per screw

has given a new injection for further research In this field.

The different facets of the problems, introduced by the

non

uniform flow at the propeller, may be summarized in four grotips.

The efficiency loss of the propeller due to unsteady flow

phe-nome na .

The Interaction between ship's hull a

propeller.

o. Cavitation phenomena on the propeller.

d. The forces excited by the propeller in the hull and the shaft.

With respect to groupaitcanbe stated that, according to

theoretical calculations, the loss in efficiency of the propeller

due to unequal flow effects is in the order of magnitude of about

one or two per cent.

_[+]

Group b comprises the Influence of the hull form

on total

resistance, total propulsive efficiency and on thrust deduction.

The dimensions of the screw aperture are in this case also included

in

the hull form. In general the rule holds, that an iprovernent

in resistance qualities does rt consequently include as

a matter

of course a reduction of the required horse power at a certain

speed. The reduction in resistance is in many cases counterbalanced

by a change in interaction effects between hull and propeller.

The purpose of the investigation, described in this paper, is to

homogenize the flow at the propeller by modifying the hull shape,

in particular the afterbody, in such

a way that no increase of the

required horse power in the service conditions

occurs.

In 1932 Igner has already presented results of tests with

an

extreme shape of afterbody. L remarkable reduction of the

circum-ferentia]. inequality of the wake was attained with a single screw

ship model, the resistance however was increased by

_5.5

_{per cent.}

Paper to be published at the annual meeting of the Society of Naval Architects, Nov. 1959e

Doctor of Science, Assistant Director, Netherlands Ship Model Basin, Wageningen.

Chief Draughtsman, Netherlands Ship Model Basin, Wageningen,

I

T1 EFFECT OF SHAPE OF AFTERBODY ON PROPULSION.

NEDERLANOSCH SCHEEPSBOUWKUNDIG BIZ.

at the service speed arxi nc propulsion tests were carried out.

The boom in high-powered tanker-building after the last war

has led to many cases of vibration troubles axil cavitation-erosion

damage on the propeller blades.

For this reason a group of scientists

in Germany attacked the

propulsion problems of single screw ships with new experimental

techniques and theories. [53 [63

[7_J [83

Simultaneously the main part of propeller research at the

Netherlands Ship 'bdel Basin was directed to the dynamical

pheno-mena excited by the non uniform flow behind the ship.

9[10 [11]

Three years ago a large systematical investigation into the

effect of shape of afterbody on propulsion was started at the

N.S.N.B.

The basic ship type was a 39000 tons deadweight tanker, the

maximum size that can pass the Suez Canal in loaded condition.

The examined variations in afterbody are:

Optimum shape from an efficiency point of view, based on

sta-tistical data of the N.S.M.B. (MDderately U-shaped sections).

Extremely V-shaped sections.

Extremely ti-shaped sections.

Cigar-shaped stern with Mariner rudder arrangement (Ibgner

afterbody).

Extremely U-shaped sections combined with a screw in a nozzle.

Extremely U-shaped sections combined with two

screws, each

fitted inaIx)zzle,one above the other.

A twin screw arrangement.

Resistance- and selfpropulsiori tests were carried out with

four- and five bladed propellers in the loaded and light condition.

Wake measurements with Pitot tubes and flow observations with tufts

have been made. Cavitation tests in the tunnel with adjustable flow

were carried out. Finally the variations in the propeller thrust

and torque during one revolution were recorded and analysed.

1. Description of the investigated hull forms arid propellers.

The designs have been made for a 39000 tons deadweight

_tanker,

having an engine power of 16,000 S.H.P. arid

_{a speed of 16 knots.}

The principal dimensions arid coefficients are given in Table

1a

_and

NEDERLANDSCH SCHEEPSBOUWKUNDIG BIZ.

The bodyplans and screw arrangements of the afterbody variations

are presented in fig. 1, 2, 3 and 1

The scale of the models is 30. The models have been manufactured

of paraffine wax. Each model except the ttHogner" model is built

up

of two half s

a forebody and an afterbody. The afterbody models have

al]. been tested with the saine forebody model. A trip wire,1 mm

dia-meter, was fitted to girth the model at a section 5 per cent. LBP

abaft F.P.P. for turbulence stimulation.

The characteristics of the various propellers are given In

fig.

5a

and

5b

The screws have been designed according to the

circulation

theory for wake adapted propellers. [12]113J

The nozzle arrangements have been designed from the data given

in ref. 113]

Screw k and B are respectively +- and 5-bladed wake adapted

screws for afterbodies I, II and III. Screw C Is a four bladed wake

adapted screw for afterbody IV. Screw D belongs to afterbody V and

screws E and F to afterbody VI. The three bladed screws G have been

designed for the twin screw arrangement afterbody VII.

The design R.P.M. for 16,000 S.H.P. at a speed of 16 knots are

for screws A, B, C and D

106 r.p.m.

for screws E and F

210 r.p.m.

tor screw G

120 r.p.m.

All propeller models have been manufactured of bronze. The

nozzle for afterbody V has been manufactured of "perspex",

_a

colour-less transparent material.

2. ResIstance and Propulsion Tests.

A summary of the results of the resistance arid propulsion

tests in the loaded and light condition Is given In table

11a

and

Full details of the results are presented in the Appendix.

Tables II

and

11b

show:

The hull form I, (moderately U-shaped sections) which is

op-timum according to statistical data of the N.S.M.B., Is still

optimum with respect to delivered horse power at 16 knots.

Afterbody II, (extremely V-shaped sections) is to be

recom-mended from a viewpoint of resistance. However the propulsive

elf iciencyis low, which is mainly due to the low hull

efficien-cy. The reduction of the thrust deduction from 0.26to o.2

by application of the five bladed screw B behind afterbody II

is noteworthy.

NEDERLANDSCH SCHEEPSBOUWKUNDIG BIZ.

PROEFSTATION WAGENINGEN _NO.

3)

Afterbody III (extremely U-shaped sections) is respectively

3 and 2 per cent. worse in resistance and power absorption

than afterbody I.

L1.) The cigar shaped after'body IV, (Igner) is really bad from a

view point of resistance. However the propulsive efficiency

is such, that In the loaded condition only 3 per cent, more

power than for afterbody I is required. In the light condition afterbody IV requires 2 per cent, more power than the

optimum hull form.

Afterbody V, (extremely U-shaped sections combined with a ducted propeller) is practically equal to the optimum hull form with respect to power absorption.

Afterbody VI, (extremely U-shaped sections and two screws in nozzles one above the other) is from a power absorption view-point very bad.

The normal twin screw arrangement, afterbody VII Is In the loaded and light condition respectively 5 and 6 per cent. worse in power absorption than afterbody I. The higher r.p.m.

chosen for this twin screw arrangement is partly explaining this higher power absorption.

3.

Results of the wake surveys.

Pitot-tube measurements have been carried out both in the

loaded and the light condition for afterbody I and in the loaded condition only for the other afterbodies.

In fig. 6a,b and 7 the results of the wake surveys are given.

From these figures it can be seen that

The extreme wake values for afterbody I and III are practically equal.

In the light condition the circumferential unequality is more

pronounced than in the loaded condition. (Afterbody I).

The circumferential unequality behind afterbody II is worse than that behind afterbody I and III.

Afterbody VII, the twin screw arrangement, shows a reduced

circumferential unequal wake pattern as compared with that of the afterbodies I, II and III.

-Aft erbody IV, the Hogner hull form, shows the most homogeneous wake pattern of all afterbody variations.

NEDERLANDSCH SCHEEPSBOUWKUNDIG RIZ.

f.

Flow observations with tufts.

With an underwater camera and two flash lamps the flow around the various afterbodies could be observed photographically. The photographs I

are reproduced in fig. 8a arid

It appears that the models without propellers do not show marked separation phenomena. However 1f a propeller Is fitted all after-bodies show a disturbed flow at the cruiser stern directly over the

screw in the loaded condition.

In the light condition the propeller of afterbody IV suffers from air sucking.

In general it may be concluded that the flow observations at the examined afterbodies do not indicate bad qualities of the lines.

5.

Tests in the cavitation tunnel with flow regulator.

Cavitation tests with propeller models are generally carried out In the cavitation tunnel with flow regulator. The best result to be obtained in this tunnel is, that the cavitation picture is considered to be acceptable. Acceptable means in this respect that only a small

stationary sheet of cavitation occurs in the vertical position of the blades. The sheet Is considered to be stationary if no traces of cloud cavitation leave the trailing edge of the sheet. In these

cavitation tests, the full scale conditions are reproduced as close as possible.

The observations, made during the tests In the cavitation tun-nel with flow regulator are presented In fig. 9 andlOa,b.

From these figures It appears that:

The screws do not suffer from face cavitation, except screw B with afterbody I in the light condition.

Screw A behind afterbody I, II and III does not show large dif-ferences in the cavitation pattern.

There are no large differences in cavitation pattern between screw A (four bladed) and screw B (five bladed) behind afterbody I under different loading conditions.

Screw C behind afterbody IV (Hogner) suffers less from cavitation than the other, single screw arrangements.. There is a considerable reduction of the back cavitation. The tip vortex Is strongly

de-veloped over wide range of the circumference due to the high

wake.

NEDERLANDSCH SCHEEPSBOUWKUNDIG BLZ.

Screw D ja the nozzle shows a remarkable reduction In cavitation phenomena in regard to screws A and B. Especially if the much

smaller diameter of screw D is taken in mind (5700 _imii).

Screw G of the twin screw arrangement has the most favorable cavitation picture if compared with the other investigated variations, despite the fact that the inequality of the flow behind the twin screw ship is greater than behind the Hogner

form. This result is due to the decrease in screw loading.

6. Measurements of thrust and torque variations.

The recording

and

analysis of the force-vibrations in the shaft, excited by the propeller model, is a kind of experimental research which has been developed In the various ship model la-boratories during the last years. [1oj

An example of the dynamic thrust and torque records is shown in fig. 11.

In table Iflttanalyzed thrust and torque measurements are given.

The following conclusions can be based On table lU.

a _{The first harmonic component of the records of the four bladed}

screws (i.e. at a frequency of four times the r.p.m. or r.p.s.) is the most important.

The five bladed screw B does not show marked differences in the

amplitudes of the first

_and

second harmonic components (i.e. at

freguencies of ₅ resp. 10 times the r.p.m. or r.p.s.)

Afterbody IV, the Ibgner hull form, reduces the thrust and torque variations considerably due to the decrease in circum-ferential inequalities of the wake flow.

Afterbody V, i.e. Afterbody III combined with a screw In a

nozzle, produces smaller thrust variations. The torque variations do not show this homogenizing effect of the nozzle.

The thrust and torque variations of the five bladed screw are much smaller than those of the four bladed screws. However the variations in bending moments In the shaft excited by the pro-peller have not been considered in these measurements.

NEDERLANDSCH SCHEEPSBOUWKUNDIG SLZ.

7, Final considerations ar Conclusions.

This investigation gives a review of different model testing techniques. It Is tried to present the results of the tests in a

form both instructive and meaningful.

The investigation Into the effect of shape of afterbody on propulsion being completed, it may be asked which hull form has to

be recommended.

Afterbody II, with the extremely V-shaped sections ar

after-body VI, with extremely U-shaped sections and two screws in nozzles, one above the other, cannot be recommended at all. The high absorbed

horse power at service speed ar r particular advantages of the

other examined qualities are the main reasons for this conclusion. Afterbody VII, the twin screw arrangement, has some advantages with respect to cavitation and thrust and torque variations. However the 5 resp. 6 percent. higher power absorption at service speed

must be considered asa serious draw back.

Afterbody III, with extremely U-shaped sections, is considered to be acceptable.

Afterbody V, i.e. afterbody fI with a screw in a nozzle, shows too small improvements to convince the constructors to consider the mechanical problems of the manufacture of a nozzle, having a

5.7 ni

inner diameter.

Finally afterbody I, representing the optimum shape based on statistical data of the N.S.N.B. and afterbody IV the Hogner hull form remain. Both solutions are considered to be good.

Afterbody I is optimum from a power absorption point of view. Afterbody IV is to be preferred from a cavitation as well as from a thrust and torque variations point of view.

M.ich depends on the experience of the shipowner or the

ship-builder. Is a sole piece in the screw aperture applied or not? If

for mechanical constructive reasons a screw aperture with sole piece should be applied, afterbody I is recommended from a

hydro-dynamical point of view.

If the sole piece is omitted the Hogner hull form i.e. after-body IV is recommended. In the experience of the N.S.M.B. the

NEDERLANDSCH SCHEEPSBOUWKUNDIG BIZ.

application of afterbody I without sole piece in the screw aperture

combined with a "Mariner" rudder is useless, The thicker Mariner

rudder leads to a two per cent, higher power absorption. Afterbody

IV is the logical consequence of the omittance of the sole piece.

If the Mariner rudder is accepted, full advantage should be

taken of the possibility to homogenize the wake flow by the shape

of the afterbody.

The effect of the shape of the Ikgner form on course stability

and the rudder area is an item for further research.

The favorable results with the screw in the nozzle, having an

inner diameter of

5.7

m, this being i .+ n less than the open screw

of afterbody IV, justify further research. Therefore the N.S.M.B.

intends to continue the research on afterbody IV, the I,gner hull

form, in combination with a nozzle. A complete nozzle ring can be

fitted with four brackets to this afterbody and a converitial Oertz

rudder can be applied. This solution might contain

some promises

for the near future.

NEDERLANDSCH SCHEEPSBOUWKUNDIG BLL

PROEFSTATION WAGENINGEN _NO.

TABLE 1a

Principal dimensions and coefficients of the ships. Iaded Condition:

L.C.B. L.C.B.

L.C.B.

of afterbodies I, II, III, V and VI 0.015 LB forward of

'station 10.

of afterbody IV 0.019 LB? forward of station 10.

of afterbody VII 0.011+

_LB.p.

forward of station 10.

Light Condition:

In the light condition the immersed volume is

V =

3,000

the drafts of the ships with the afterbodies I, II, III, IV, V and

VI

df

d = 7.696

m daft = 8.077 Zn,

that of the ship with afterbody VII

d

= 7.887

m (at even keel)

Length between perpendiculars LBP 205.1+5 Zn

Breadth B

28.50

m

Draf t d 10.79 m

Wetted Surface s 8,1+oo

Immersed Volume

V

1+8,900 Zn3

Half angle of entrance

26.50

Blockcoefficient _¿B.?. 0.71+1+

Midship Area coefficient ¡3 _0.996

Prismatic coefficient _TBSP. 0.777

NEDERLANDSCH SCHEEPSBOUWKUNDG BLZ.

TABLE Screw characteristics. Screw A B C D E F G Diameter D in 6900 6800 7100 5700 3300 3300 5900 Pitch at hub h in +37+ 11.311 +362 6786 21+35 331+6 1+100 Pitch at tip P0 in n 5660 579f 5356 7510 1+002 14.010 14.755 Pitch at O,7R Po in 5250 5358 1+876 681+7

3535

3508 1+755

Pitch ratio 0.761 0.788 0.687 1.201 1.071 1.063 o.8o6

Disc area ratio AnJA0 0.529 0.571+ 0.527 0.6+3 0.787 1.035 0.351

Number of blades 5 14- 1+ 14. 14. 3

NEDERLANDSCH SCHEEPSBOUWKUNDIG BIZ.

?ABLE

11b

Results of resistance andseif propulsion tests

- Light condition - Speed 17 knots.

Afterbody

Screw

Number

of

blades

total resistance

in percentages

(afterbody

1=100)

D.H.P.

In percentages (afterbody 1=100)

propulsive

coefficient

thrust

deduction t

wake

fraction w

relative

rotative efficiency

X (moderately U-shaped) A 14. 100 100

O.7

0.22 0.35 1.05 II (extremely

V-shaped)

A + 97 1o6 0.67 0.26 0.31

III (extreme- ly U-shaped)

A + 103 102 0,75 0.23 0.+2 1.03 IV (Rogner form) C + 1o8 103 0.77 0.23 0.+3 1.02 V (III + nozzle) D 103 101 0.75 VI (III + 2

nozzles)

E and F Lf,) 106 11+ 0.69 VII (twin screw) G 3 100 105 0.70 I (moderately

U-shaped)

B 5 100 S 101 0.73 0.23 0.35 1.05 II (extremely

V-shaped)

B 5 97 103 0.69 0.2+ 0.32 III (extremely U-shaped) B 5 103 101 0.76 0.23 0.+2 1.0+

Afterbody

Screw

Number

of

blades

total resistance

in percentages

(afterbody 1=100)

D,H.P,

in percentages

_{(afterbody 1=100)}

propulsive

coefficient

thrust

deduction

t

wake

fraction

w

relative

rotative

efficiency

I (moderately

U-shaped)

A )f 100 100 0.77 0.23 0.38 1 .05 I-v. (lkgner form) C + 107 102 0,81 0.23

0.7

1.01 VII (twin screw) G 3 97 106 0.70 I (moderately

U-shaped)

B 5 100 100 0.77 0.23 0.39 1.05 TABLE U

l.,z

- w

o In Lu w X o VI

'no

-JIn IL w W wnC Zo.

TABlE Ifl.Results of dynamic thrust and torque

measurements.

Loaded condition speed 16 knots Light condition speed 17 knots Amplitudes of Amplitudes of Amplitudes of Amplitudes of number the harmonic the harmonic the harmonic the

harmonic

Afterbody screw of

components of

components of

components of

components of blades the thrust as the torque as the thrust as the torque as a percentage a percentage a percentage a percentage of the total of the total of the total of the total thrust torque thrust torque. i st 2ixl 3rd 1 st 2nd 3rd 1 st 2nd 3rd 1 st 2nd 3rd I (moderately A 13 1 12 3 1 17 3 1 9 1 0 U-shaped) II (extremely A L1. 1L1. 3 3 8 1 1 V-shaped) III (extremely A 17 L1. 1 10 1 0 U-shaped)

IVkgnerforin)C

9 5 2 1 0 12 2 9 0 0 V(III + nozz1e D 13 1 2 10 1 1 I (moderately B 5

3.

2 1 2 1 0 2 2 1 2 1 0 U-shaped) II (extremely B 5 2 3 1 2 1 0 V-shaped) III (extremely B 5 6 3 0 1 1 0 U-shaped)'

Literature.

E

i]

Kampf, G. and Foerster, E.: "Hydromechanisehe Probleme des

_{Schlffsantrlebs't, Chapter V, Hamburg, 1932.}

[ 2J

Nartinek, J. and Yeh, G.C.K.: "Final report on theoretical

_{studies on steady fluid motion under a free}

surfacet', Reed Research Inc.-Project RR-1373,

i 958.

Martinek, J., Yeh, G.C.K. and Crawford,

L.: "Firl report on

research and investigation on thrust deduction",

Reed Research Inc.-Project RR-815, 1953.

14artinek, J., Yeh, G.C.K. and Zorn, B.C.: "Theoretical studies

of wake and thrust deduction, A contribution to

potential theory in three dimensions", Reed

Research Inc.-Project RR-815 B, 1955.

E3]

Manen, J.D. van and Troost, L.: "The design of ship screws of

_{optimum diameter for un unequal velocity field",}

Trans. of the S.N.A.M.E., 1952.

E+1

Lerbs, H.W.:

"The loss of energy of a propeller in a locally

varying wake field", D.T.N.B.-Report no. 862,1953.

E5]

Schuster, S. and Walinski, E.A.: "Beitrag zur Analyse des

_{Propellerkraftfeldes", Schiffstechnlk, Heft 23,}

i 9 57.

i: 61

Nitzki, L.:

"Versuch einer vergleichenden Auswertung der

_{Meilenmessfahrten der "Olympic Cloud" und der}

Ìdellversuche", Schiff und Hafen, 195+.

Nitzki, L., Book, W. and Zhlke, S.: "Einige Beiträge zu

Propulsionsfragen aus Messungen an der

Gross-ausführung und an Versuchsserien", Schiff stechnik,

Heft 23 & 2+, 1957.

[ 7]

Metzmeier, E.: "Die gekoppelten Längs- und Torsionsschwingungen

der Wellenleitung", Schiffstechnik, Heft 27, 1958.

i:

8]

Krohn, J. :

_{verschiedener Hinterschiffsform auf die Schub-}

"aber den Einflusz der Propellerbelastung bei

und Drehinomentschwankungen am Modell", Schiff

und Hafen, 1958.

[9]

Lammeren, W.P.A. van: "Testing screw propellers in a cavitation

_{tunnel with controllable velocity distribution}

over the screw disc", Trans. of the

S.N.A.M.E.,

1955.

[io]

Manen, J.D. van and Wereldsma, R.: "Dynamic measurements on

propeller models", Symposium onthe Towing Tank

Facilities Instrumentation and Measuring Technique,

Zagreb, Sept. 1959.

[ii]

Wereldsma, R.: "Model tests for determining critical vibrations

of the rudderpost of a "mariner" rudder'1, Deif t

Conference - The Institute of Physics - Stress

Analysis Group, April 1959.

Manen, J,D. van and Lainmeren, W.P.A. van: "The design of

wake-adapted screws and their behaviour behind the

ship", Trans. of the I.E.S.S., 195+/55.

Manen, J.D. van: "Open-water test series with propellers in

nozzles", Intern. Shlpb. Progr., No. 2, 1951+.

Manen, J.D. van: "Recent research on propellers in nozzles",

Journal of Ship Research, vol. 1, nr. 2, 1957,

Intern. Shipb. Progr., No. 36, 1957.

Manen, J.D. van and Superina, A.: "The design of screw-propellers

in nozzles", Intern. Shlpb. Progr., No. 55, 1959.

NEDERLANDSCH SCHEEPSBOUWKUNDIG BIZ.

AP P

MDIX

Bi. 14.

Meu1t

of re3itaflc

and seLf propulilon

st

in

h

1oadd condition.

ID3IANCE TX$

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in knots

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0.729

11I.11

0.227

0.3+3

0.378

0.585

.05)3

I?

)0996

91.I1

0.710

15)19

1Q),3

0.727

121.119

0.225 0.312

0.382

0.583

.060

17.5

12372

102.05

0.732

17)16

108.6

0.723

_1?3.06

0.227

0.338 0.386 o.SCo

.o67

le

_l392

112.61

_0.758

19591

_1)3.3

_0.71)

1+6.27

0.l3O

0.336

0.392

0.576

.06k

1)3.5

17l

121.10

0.79)

221

118.3

0.703

)62.3'+

0.236

0.332

0.398

0.572

.073

19

193

138,5+

0.83)3

26222

_123.6

0.690

131.68

0.237 0.337 0.l2 0.562

.068

Afterbodv II

I1

_5F29

56.+)

0.628

8085

86.7

0.67)

76.)3

0.259

0.3111 0.31+8

_0.603

_.032

(xtromo1

111.5

6062

60.83

0.630

9018

89.13

_0.672

82.26

0.261

0.31+ 0.3f9

0.602

.035

V-hapod)

15

67'6

65.F3

0.61

10083

93.2

0.669

88.66

0.262

0.3)2 0.3f9

0.602

.035

with sorow A

_i5.5

₇₅₃₀

70.69

0.&2

11269

_96.7

0.668

95.75

0.262

0.311

_0.35)

0.601

.o8

i..biaded

16

_8'36

_76.70

o.651

12586

100.3

0.670

103.5)

0.259 0.309

0.352

0.600

.012

16.5

91*51

_83.33

0.667

₁₊₀₇₆

I0F.l

_0.671

1)1.95

0.26 0.308 0.355 0.599

.01+2

17

₁₀₆₆₉

91.31

0.688

15820

108.0

0.671F

121.62

0.249 0.307

0.359

0.597

.01+1+

17.5

)20'E8

100.16

0.713

17900

112.1+

_0.673

12.66

0.2)15

0.302

0.361

0.595

.o'+5

18

13652

1 t0.31+

0.713

20333

1 17,0

0.671

1+5.59

0.2+2

0,298

0.365 0.593

.0+9

18.5

15511

121.)8

_0.776

23200

_12).?

0.666

161.12

0.2+3

0.296

0.372

0.589

.053

19

17816

136.42

_0.825

27050

127.+ 0.659

i)3i)

Ò.2+7

0.300

0.386

0.580

.055

Aforhodv II

)lI. _{5+29 56.1+)}

_0.628

₇₈₅₃

8) 0.69)

7l77

_0.2}6

_0.3)5

_0.391

_0.603

.01+)

(oxtromo1y

11+.5

6062

60.133

_0.630

13751

8.1

0.693

80.77

0.21+7

0.3)6

0.35)

0.602

.1)1+5

V-hapod)

%5 671+6

65.'+3

o.61+

₉₇₇₅

9) .3

0.690

87.03

0.21+8

0.3)8

0.3'f 0.60)

.O+2

wit))

CrW B

_5.5

₇₅₃₀

_70.69

0.642

₁₀₉₀₇

9+.6

0,690

93.70

0.21+6

0,315

0.31+

0.60)

.01+3

5b1ad4d

16

)3+36

76.70

0.651

12177

9)3.2

0.693

lOI .19

0.21+2

0.316

0.350

_0.599

.01+3

16.5

9)151

83.33

0.667.

l652

_101.9

0.692

l09.0

0.239

0.313

0.359

0.590

_.0)15

17

1066e

91.31

0.688

1452/

105.13

0.692

¶19.31

0.23,5

0.312

0.363

0.595

ol5

17.5

1201+13

100.16

_0.713

1751p

110.2

0.608

10.75

0.231

0.308

0.36? 0.593

.01+9

18

13652

1 l0.3+

_0.713

_l99f52

I )l)3

o.6)3+

I t)+.09

0.23+ 0.306

0.373

_0.58?

.053

18.5

1511

121.8

0.776

228+)

119.6

0.679

159.35

0.235 0.305

0.38)

0.58+

.057

19

1716

136.62

0.825

26556

125.2

0.67)

177.60

_0.232

0.303

0.39)

0.577

.055

A6terbody III

i1+ 5869

60.98

0.679

7I56

81 .1+

0.777

78.32

0.221

0.1+31 0.1+21+

0.555

.023

(cxtremo1y

)15

6559

65.8)

0.683

8492

)7+.8

0.772

81+.5)3

0.222

0,1+26 0.1+23

0.556

.025

U-hapd)

I 5 7303

70 .83

0 .6)36 95313

88.2

_0.766

_{9 I .39}

0.225 0 .1+23

0 .1+23

0.556

_.025

W1Ih icrow A

15.5

8)20

76.2)

0.692

1068G

91 .6

0.'/60

98.60

0.227

0.1+20 0.1+23

_0.556

.025

1+-biad.y.t

16

90l+

81.96

0.699

12016

95.2

0.750

06.61+

_0.231

0.1+16 0.1+21

_0.556

_.025

)6,5

10019

)33)

0.708

13565

99.0

0,739

i6.o+

0.29 0.+12

0.'+2

_0.555

.027

I?

11270

96.6

0,727

15+26

_103.3

0.731

26.91+

0.2lO

0.1)08

0.+27

0.553

.02Q

17.5

)279)3 106.1+0

0.757

17550

)07.8

0.729

39.19

0.236

0.1+01 0,1+28

_0.552

.0

18

11+61+1+

118.36

0.797

2002)

112.6

0.731

52.95

0.226

0.391+

0.+3l

0.511+

.010

18.5

16717

131.62

0.839

229)7

1)7.8

0.730

68.89

0.221

0.390 o.+6 0.546

.o1+8

)9

19146

I 6.60

0.886

2666'+

_123.5

0.718

_89.17

0.225 0.386

o.1++

L°'1

.052

Aft+bodv III

11+ ₅₈₆₉

60.98

0 .679

785

80.5 0 .77l

7)3. 58 0.221+ 0 .1+35 0.1+31+

0.5+7

.029

(oxtrenioly

)l+5

6559

65,8)

0.683

8+59 133.7

0.775

8'+.99

0.226

0.1+30 0.1+31 0.51+9

.038

U-Jhap3d)

I 5

7303

70 .83

0.6)36

91+58 _{87 .0}

_{0 .772}

_{91 .79}

_{0 .223}

0 .'+28 o .1+31 0. 519 .01+1+

with 3ow B

1 5.5

81 20

76.21

0.692

l089

90 . O .767 9)3.1313

_{0 .229}

_{0 .1+25} 0 .1+3) 0 , f9 .1)1+2

5-b1athd

16 9011+

81 .96

_0.699

I 1890

_93.

o.y8

106.78

0.232

0)+21

o.!31

0.51+9

_.0i0

16.5

10019

88.&1+

0.708

13392

97.6

0.7+8

115.35

0.23)+

0111q

0.1+30

0.550

()l)4)

17

11270

96.46

0.727

15156

101,7

0,71++

125.30

_0.230

o,'of

0.1+30

0.50

.o8

17.5

12738

106,I,o

0.757

17190

105.9

Ø,7)1

137.02

0.223

0.1+07

0.+35 0.6

.012

18

jI)341

_1)8.36

_0.797

₁₉₆₁₁₊

_{110,5 0.71+7}

151.01+

_0.216

_0.1+02

_0.'+9

l).5l

_.030

18.5

l677

1».62

0.89

22530

115,6 0.7+3

168.06

0.21?

0.l00

o.l++7

0,53

.05)3

19

191+6

1+6,60

0,86

26227

12).0

0.730

188.91

0.22+

0,l01

o.+58

0.529

.066

Aftoibody 1V

11+ 5981

62,16

0.692

7571

82,)

0.789

80.62

0.230

0.1+1+1+ 0.1+00

0.557

.023

(lbgnor

ori)

_1+.5

6730

67.51

0.70)

81+8

85.3

0.791

_87.l0

0.228

0.l+1+1*

0.l02 0.556

_.025

with orow 0

15

7531+

73.08

0.708

9546

88.7

0.789

9'+.52

0.227

0.1+39

0.i0o

0.55?

.027

1ibiadd

15.5

8+18

79.02

0.717

10768

92.3

0.781

102.15

0.227 Q,)37

0.1+02

0.556

.023

16

9396

0.728

12170

96.0

0.772

110.59

0.227 0.+32

0.'+02

o,556

.020

16.5

10522

92.78

0.71+1+

13770

100,0

0.763

120.39

0.230

01+33

0.I07 0.2 1.018

17

11802

101,00

0.762

156)7

10.9 0.755

1)1.56

0.233

0.1+33 0.1+13

o.;+8

_1.018

17.5

110.70

0.789

17707

ion.2

0.751

141+.6+

0.235

0.1+32 0.1+19 0.91+1+

l,02i

18 1+987

121,11

0,817

20273

111.1

0.739

158.66

0.237

0.1+21+ 0.1+20 0.51+3

1.026

1)3.5 1703)3 133,1+4 0.051+

23333

110.3

0,730

l7l,87

0.2.3+

0.1+18

0.+23

0.91+1

1.026

19

19627

150.33

0.909

272)2

I2+.2

0,721

195.98

0.233

0,1+11+ 0.1+32

_0.535

_1.030

Afteibody V

11+ ₅₇₁₊₃

59.68

0.665

71+86

79.0

0.767

60.1+?

(XII + no2zlc)

1,1,5

6+26

6+.1+8

0.670

81+27

82.2

0,763

65.2'+

with

row D

15

7175

69.60

0.67

9'+6'+

85.3

0.758

'/0.55

1i-blado0

15.5

80)6

75.2'+

0.684

10628

88,6

_{0.751+ 76.515}

16

₈₉₃₀

81.20

0.693

11977

92,1

0.7'6

82,9+

16.5

9975

_87.95

0.706

13501

_95,9

_0.739

90,30

17

₁₁₁₅₆

9)5.1+?

_0.721

₁₉₃₁₊₆

_100,0

_0.727

_90.60

17.5

₁₂₅₆₃ lO +,1+1+ 0.71+5

1757)

1o'+.ó

0.715

108.28

18

11+263

115.28

0.776

20280

_109,0

0.703

1)9.85

18,5

16269 127,91+

0.817

231+61

115,0

0.693

112.66

19

₁₀₇₁₅

_11+3,31 0.1367

27)27

120,5 0.690

167.10

A1trbody VI

11+

₅₉₂₇

61.53

0.636

83)8

167,3

0.71)

_1+Q,16

(III +2

I)+,5

6630

66.52

0,69)

9380

171+.)

_0.707

_54.06

no1o)

15

71+00

71,77

0.696

₁₀₅₆₂

181,0

0.70)

59.10

with screw 8

_15,5

8262

_77,55

0.701+

11950

180,0

0,601

61+,56

and F

16

9230

83.93

_0.7)6

131+63 195.1+

0.686

/0/5

1+-bladad

_16,5

10316

90,95

0.7)0

152)2

_203.1

0.677

76.l

17

₁₁₅₆₉

90.02

_0.763

₁₇₎₆₉

211.6

0,667

3+.o1+

17,5

I302l

100,25

0.782

19802

220,6 0.58

_91.93

18

1 +731+ _{119.1)9 0.1303}

₂₂₇₀₃

230,5 0,6+9

_100.79

18.5

168«8

_132.57

0.01+6

₂₆₀₉₅

21+1,0 0.61+6

iio.1+5

19

19640

_150,38

0.909

30183

252,6

0,651

121.21

AItrbody VII

11+

5656

58.78

_0.652

7729

96.3

0.732

68.37

(twin so'sw)

i+.5

6271

62.92

0.650

8733

100,2

0.7113 7t+.36

with screw G

15

6979

67.69

0.651+

₉₈₁₇

1O+.1

_0.711

_80.90

3-bladed

15.5

7771+

72.97

0.669

11028

108.0

0.705

_87.98

16

872)

79.29

0,672

121+1+0

1)2,2

0.701

9)5.61

16.5

9778

86,21

.0.687

l'01+6

116.3

0.696

10+,05

17

₁₁₀₃₈

91+.+7

0.709

1'900

120.?

0,691+ 1 11+.co

17.5

12513

lO'+,03

0.737

1801+0

l)5,l

o.69+

125.1+1

18

₁₁₊₂₃₂

_115.0)

0,7/1

₂₀₅₈

130,1+

_0,691

138,24

1)3.5

16262

127.88

0.1312

₂₃₅₀₊

l35.5 0.692

_152,95

19

₁₈₇₁₂

11+3,23

_0,061

27167

111,)

O689

170.52

APP

MDIX

R03u1t$ of re3lstance and

e1f proju1i1on testa in the light condItion.

BI3I2AJ TE$1'

LF-ROP1JL3ION TE3S

$LIP, WAI

ETC.

Speed

in knots

BrItIsh

H2 '

liesistance

in tone

®

British

DHP

R.P.M.

77,

Thrust

tons

t

w

slip

'

Aftorbod

I

1 ₆₀₈₃ 9.CO

0.720

₇₇₂₆

_8F,5

_0,767

76.

_O.233

_{0.398 0.372}

O,589

1.Oi.9

(inod?rately

_1.5

6813

_63.96

O.7:kO

₈₆₇₈

_87.9

_O.78

_83.

_0,234.

_O.391f

_0.372

_o.589

1.051+

U..shaped)

16

7636

69.+3

O.74

9789

91 .5

0.780

90.57

0.233

_0.389

_0.372

_0.589

I .O6

with sorew A

_16.5

_8'67

_75.53

_0.761

₁₁₀₉₁

_9Ç.2

_0.?72

_98,47

_0,233

_0.387

_{0.376 0.87}

_1.051

)+..bjaded

₁₇

₉₆₆₃

_82.70

_0.785

1258Ç

_99.2

_0.768

_107.12

_0.229

_0.380

_0.376

_0.587

_1.053

17.5

1093i

9Q.90

0.813

111.306

_103.+

_0.76

_117)i0

0,226 0.377

_0.380

_O.58'i.

_1.053

18

1226

_100.+3

_0.851

16322

_107,9

_0.761

_128.70

0.220

_0.370

_0.382

_0.583

_1.053

18.5

1F1tF9

111.27

o.8Q2

18726

112.7 0.76

_12.O6

_{0.217 0.365 0.388}

_0.579

_1.057

19 16193

12+.00

0.941

21778

118.1

_0.7

158.6?

0.219 0.361 0.97

0.57i.

1.057

19.5

1818

138.16

0.996

255+O

123.9

0.725

179.09

0.229

0.359 0.O7 0.567

1.062

20 21+60

156.11

_1.072

₃₀₊₅₀

130.1+

_0.705

_205.25

_0.239

_0.363

0)+26

0.551+

_1,065

Afterbody I

15

₆₀₈₃

_59.00

_0.720

₇₇₃₉

_83.3

_0.786

_75.59

_0.220

_0.fOi

_0.378

_0.586

_1,029

(niodorate1t

₆₈₁₃

_63.96

_0.70

_87O

_86.8

_0.780

_82.40

_0.22ff

_{0.396 0.378}

_{0.586 1.06}

U-.shaped)

₁₆

₇₆₃₆

_69.1f3

_0.7+

_981f6

_90.3

_0.776

_89.75

_0.226

_0.392

_0.379

_{0.585 1 .01}

with sorow B

_16.5

₈₅₆₇

_75,53

_0.761

11121

_93.9

_0.770

98.06

_0.230

_0.391

_0.383

_{0.582 1.o6}

5.'.bladed

17

966

_82.70

_0.785

₁₂₅₆₈

9.7 0.769

_10?.'i'6

_0.230

_0.388

_0.387

_0.580

_1.053

17.5

1093i.

90.90

0.813

1k292

101.9

0.765

117.80

0.228 0.38k

0.391

0.577

1.057

18

121f26

100.+3

_0.851

163

_106.3

0.760

129.79

0.226

0.381

0.196

0.57'i

1.059

18.5

1+19

111.27

0.692

18+7

111.1

_0.751

_VF3.69

_0.226

_{0.377 0.O2 0,569}

_1.062

19

_16i9

12+.00

0.9+1

₂₂₀₅₅

116.6

_0.731f

_160.71

_{0,228 0.37+ 0.12 0.562}

_1.060

19,5

1851

138.16

0.996

25966

122.+

0.71't

181.51+

0.29 0.37f

_{0.1F25 0.53 1061}

20

21+60

_156.11

_1,072

₃₀₉₃₁

128.8

_0,69

_207.70

0.28 0.376 0.+2 0.561

_1.065

Afterbody IV

15 6523

63.28

0.76'

7697

82.5 0.8i7

81.17

0.221

Q,).77

0.(99

_{0,558 1.020}

(}Iognor form)

15.5

₂₃₁₅

_68.67

_0.776

866o

_85.8

_o.8i+

_88.25

_0.222

0.i76 0.O2 0.556

_1,023

with soi'ow c

Ii..bladod

.

is

1 6 5

17

8180

9206

10369

7+.39

81 I 7

88.7f

0.789

0 81 o

0.83ti

9833

i i 2'7

12856

89.5

93 .3

97.2

0.832

0 81 8

0.806

96.15

1 0 5. 1 'i.

115.35

0.227

.

228

0.231

0.73

0

0.72

O.+03

O +07

o.+16

0.555

O 5'2

0.516

1 .023

1 016

1.013

.5

g13288

11726

97,)9

0.865

P+715

101.6

0.796

126.93

0.232

0.f66 Q.'18

o.5+5

1.018

i 8 5

i 51 +o

i i 9 .06

I07.iO

0.900

0 93'5

168/3

I 9+81

106,4

_{i i 1 .7}

0.787

_{0 .777}

1+0.00

_{1 55.1 2}

0,233

_{0 .233}

O.+7

_{0 .+47}

0.19

_{O .+20}

0.51i+

_s51+3

1.021,

_{1 .031}

19

17299

12.i6

0.999

22689

117.2 0762

173.2F

0.236

0.4t2

0.+28

_0.537

_1,035

19.5

20017

1I9.35

1.069

26837

123.7

0.7+5

195.85

0.238 0.1 0.++i

0.527

1.036

20

23+26

170.fl

1.159

Afterbody VII

15 5931+

_0.703

¿38o

100,1

0.711

69.73

(t,in screw)

_15.5

6628

;

62.21

0.709

92+

10f.i

0.703

75.73

with $orew G

16

7+32

'

57.58

0.722

10605

108.2

0.701

82.Lo

3..b1aded

_16.5

8329

?3.+3

0.739

11875

112,3

0.701

89,i8

17

9358

3o.o8

0.758

13366

116.6

0.700

97.65

17.5

10557

37.77

0.785

15111

_120.9

_0.697

_106.91

18 11991 k

96.92

0.820

17283

125.8

0.69k

117.80

18.5

13671 ' i;

107.51

0.859

19798

130.7

0.691

130,3

19 ₁₅₇₂₁

_0,913

₂₃₀₁₀

_136.2

_o.68

_1+6.1

19.5

1816k

J20.37

_35.51

_0.976

₂₆₇₉₀

141.8

0,67

165.21

20

21116

_53.60

1.051