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THE HYDRODYNAMIC RESEARCH FACILITIES of the

NATIONAL RESEARCH COUNCIL

MECHANICAL ENGINEERING REPORT MB-251

By

S.T. Mathews

Division of Mechanical Engineering

March 1963 OTTAWA

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MB-251

THE HYDRODYNAMIC RESEARCH FACILITIES OF THE NATIONAL RESEARCH COUNCIL

This report describes the facilities and work of the Ship Section. It is intended to show the operation of the

Section in a way which might prove useful to those who currently use the facilities or who might have future requirements. Photo-graphs and diagrams have been used mainly for this purpose. The

report may be regarded as the framework of a manual, the text

being in the form of a commentary on the photographs and diagrams. Many of the illustrations have been selected from

routine reports, most of which are of a proprietary nature, i. for particular groups or institutions, and for this reason certain disguises have been made.

There is a multitude of special projects which have been carried out in the laboratory, not all of a hydrodynamic nature but usually with a nautical connection. These are not all recorded here, but some of the more important projects are

represented.

The major part of our operation in the past decade or

so has been of a design support nature and this work will always be considered important, not only in itself, but also for guidance

into the most useful channels for research. The present and future policy of the Section is to deliberately set aside more time for research which can be published widely. A few selected reports which have been released for open circulation are listed at the'end of the report, together with references giving more general information about the National Research Council.

The present description has been loosely divided into nine sections, as follows:

Laboratory Workshops Main Experiment Tank

Temporary Shallow Draft Tank Manoeuvring Tank.

Water Tunnel

Main Seakeeping Facilities

Temporary Small Model Seakeeping Facilities Full Scale Trials

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Page- - 2 MB-251

The following is the list of numbered illustrations with comments.

1. LABORATORY WORKSHOP

1-1. SHIP LABORATORY WORKSHOP

The shop is equipped with standard metal-working machines and, in the basement, there is woodworking machinery.

The model-cutting machine, shown with the model in place, can be used as a general pantograph cutting machine for models up

to 25 ft. x 3.5 ft. x 2 ft. Operation is from a stylus

follow-ing a drawfollow-ing on the adjacent table. A large number of scale ratios between drawing size and model size are available. Wood or wax models can be cut.

Thermostatically-controlled wax-melting tanks for temperatures up to 335°F, with a total capacity of 6000 lb.,-are installed in the laboratory. Currently, most of the models are made from wood as this is most suited to the wide range of tests carried out Wax is used on models for limited testing and where large modifications are anticipated.

The model finishing bay is also shown. Many of the specialized laboratory instruments are manufactured and serviced

in the workshop.

Projects beyond the capacity of the machinery or

number of staff are processed in the main Divisional Workshops.

1-2. GLUE PRESS WITH LARGE MODEL LAMINATIONS

A typical wood model block is shown in place on the

press.

1-3. MODEL PROPELLER SHAFT BOSSINGS BEING CUT ON A STANDARD MILLING MACHINE

The standard machine has been adapted to carry out this work directly from a bossing drawing with much saving in time as compared with hand pattern-making methods.

The next five illustrations, 1-4 to 1-8, show some of the steps in constructing an accurate .propeller. Normally

the

model propellers are of the order 8 in. to 10 in. in diameter. The particular propeller shown here was 18 in. in diameter and

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Page - 3 MB-251 was. designed. and constructed for use on a manned, high-speed,

search boat.

1-4. PROPELLER PATTERN LAMINATION DRAWING

1-5. PROPELLER PATTERN LAMINATIONS

1-6. PROPELLER MACHINING PATTERN

1-7. PROPELLER MACHINING ARRANGEMENTS 1-8. FINISHED PROPELLER

Normally, the model propeller machining patterns are constructed from a solid block of stabilized plastic-, and

accurately checked using axial offsets in a special checking machine. The casting patterns are made in wax and the metal castings sub-contracted to a commercial foundry. The finished propellers are accurately checked to give correct axial offsets within 0.005 in. and the edge thicknesses checked by enlarged photographs of wax impressions.

2. MAIN EXPERIMENT TANK

2-1. TOWING CARRIAGE WITH PROPELLER OPEN WATER BOAT

2-2. CLOSE-UP OF TOWING DYNAMOMETER AND SOME RECORDING

INSTRUMENTS

2-3. CLOSE-UP OF OPEN WATER BOAT

The propeller open water characteristics ate based on

measurements obtained with the same propulsion dynamometers, used in the self-propulsion test, installed in the open water

boat. The conventional self-propulsion analysis is subsequently

made, using these open Water characteristics. Open water

characteristics are also obtained from water tunnel experiments together with the influence of cavitation. Small differences in the results from tank and tunnel may result due to the difficulties of accurately assessing free-stream velocity in the tunnel. For this reason, the non-cavitating results from the tank are used as a standard, where possible, -and the tunnel results are used mainly to indicate the effects of cavitation.

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2-4: MODEL SELF-PROPULSION DRIVE MOTOR AND DYNAMOMETER

Self-propulsion tests are usually carried out over a range of loadings between ship and model self-propulsion point and over a range of speeds. The information obtained is then useful for assessing the effects on propulsion of over-load conditions such as those due to fouling and moderately bad weather. Special overload conditions are considered for tugs and icebreakers.

-The net six illustrations, 2-4-1 to 2-4-6, show some of the standard forms and diagrams used for summarizing hull geometry, resistance and over-all propulsion results. It

should be mentioned here that an accurate large model-sized hull form plan is drawn on a stable plastic drawing paper for the purpose of constructing each model and for calculating the hydrostatic and other form particulars. In many cases these plans and the measured offsets_ are used as the shiplouilding

standards:

2-4-1. DIMENSIONAL FORM PARTICULARS SHEET

Shows the Main ship particulars and some quantities usefullrin subsequent calculations.

2-4-2. NON-DIMENSIONAL FORM COEFFICIENTS.

Shows the main coefficients siqftifi06nt

in:

resistance and prop

sin.

24-..

NOND3MENSIONAL RESISTANCE (AND EFFECTIVE POWER) DIAGRAM

= where =. pg3/2 v7/6.

-.where

7 =

g1/2 1/6 and V =

-IP

- V

then, 3 . plotted as ordinate on V as abscissa. Vv

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In order to ,orientate this with the used, Va. Page - 5 MB-251 plot widely

Also shown on the diagram are values of other multiples Of Pv and integer powers of Vs7 which are compatible with Vv, and have practical significance. Knowing the values of ,16 and V for

any displacement, power and speed may readily be obtained from the diagram.

fI

The next three illustrations, 2-4-4 to 2-4-6, show the non-dimensional plottings of thrust, shaft speed and

delivered power from self-propulsion tests. Actual dimensional values of these quantities can quickly be obtained for any speed or resistance loading by multiplying the non-dimensional value by the appropriate reference quantity which depends only on

displacement, i.e.

H.P.) =x (H.p.)

2-4-4. NON-DIMENSIONAL THRUST VS. SPEED OVERLOAD DIAGRAM

2-4-5. NON-DIMENSIONAL SHAFT SPEED VS. SPEED OVERLOAD DIAGRAM

2-4-6. NON-DIMENSIONAL DELIVERED POWER VS. SPEED OVERLOAD DIAGRAM

2-5. FLOW PATTERNS ROUND A SELF-PROPELLED MODEL

The flow lines on the hull, propellers, rudders and other appendages are obtained by the motion of paint mixture droplets along the streamlines when the model is self-propelled

.long the tank.

The test is particularly useful in examining special features of the flow such as break-away, and for positioning appendages such as bilge keels.

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2-6. WAKE SURVEY AT MODEL STERN

The velocity distribution in the boundary layer is

obtained with the pitot rake, the pitot,pressures being

measured with an electronic transducer, each tapping success-ively being connected by means of a remotely-controlled

electrically-operated valve. The use of these results in the water tunnel is shown-later.

2-7-1. MODEL WITH PITOT RAKE WITHOUT PROPELLER

The wake distribution in the propeller disc can more conveniently be measured using a cylindrical coordinate system. The rake shown measures total and static pressures at fixed radii and at any desired angular position.

2-7-2. MODEL WITH PITOT RAKE WITI4 PROPELLER

Velocity measurements in way of the propeller give an important record of the flow conditions, possibly more so than those measured on a towed model, i.e. without propeller. The combination of towed and self-propelled results may be used to assess cyclic propeller forces and moments.

2-7-3 DIVIDING DISC OF PITOT RAKE, AND MANOMETER PANEL The dividing disc is used for setting the angular position of the rake in steps of five degrees. Electronic

transducers are now used more often than manometer panels for recording multiple pressures.

2-7-4 CLOSE-UP VIEW OF PITOT RAKE 2-7-5 VANE WHEEL WAKE METER

These are convenient instruments for obtaining

radial wake distributions on towed models to provide propeller design information. Vanes are available for radii up to 5 in. 2-7-6 TYPICAL RADIAL VELOCITY DISTRIBUTIONS

The curves compare values from vane wheels and from circumferential averaging of pitot results, with and without a propeller. The average wake from a self-propulsion test analysis for this particular model is also shown.

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MB-51

2-8. DIFFERENTIAL PRESSURE TRANSDUCER FOR USE IN WATER (HIGH SENSITIVITY)

'This is-one type of 'transducer adapted for use in'

water. Water pressure is transmitted through a thin elastic membrane to a non-corrosive silicone fluid in contatt with the-basic commercial electronic element.

2-9. OSCILLATING- MECHANISM

The illustration shows the mechanism mounted on

the test carriage and a submerged body being tested: The

mechanism can be used for surface or submerged bodies in static or dynamic modes, i.e. the test body can be subjected to heave and pitch or yaw and sway and recordings made of forces and moments. The resulting stability derivatives can be used for predicting or simulating the behaviour of vessels, as in towing, steering, submarine diving or hydrofoil craft control problems. It is expected that this facility will become of increasing importance in the work of-the laboratory.

2-10. STREAMLINE HOUSING FOR UNDERWATER CAMERA

This has been used for examining the flow of ice around self-propelled model hulls and propellers, and also for recording the directions of streamlines.

The next four illustrations, 2-11-1 to 2-11-4, show some of the arrangements and results in connection with bow manoeuvring jet experiments. The illustrations are not all

for the same model.

2-11-1 DIAGRAM SHOWING INLET AND OUTLET POSITIONS OF BOW MANOEUVRING JETS

2-11-2. MODEL PREPARED FOR BOW JET TURNING TESTS 2-11-3. .JET :THRUSTS FOR GIVEN FLOW RATES

2-11,4. SHIP TURNING ANGLES FOR GIVEN JET THRUSTS

.1.11e, Method Of manoeuvring, using boini.jets'jrom.pumpsj

is a Variation of transverSely-mounted 'DOW

Strews-.

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-MB-251

3. TEMPORARY SHALLOW DRAFT TANK

Shallow draft work for Northern river operations is carried out periodically.

This particular tank was constructed, having dimen-sions 100 ft. x 13 ft. with water up to 3-ft. depth.

The six illustrations, 3-2 to 3-7, show some recent design investigations for a particular service. The main problems are associated with running sinkage and trim, speed and power, and free-board limitations.

The illustrations show some benefits of length in this particular case.

3-1-. SHALLOW DRAFT TANK -FACILITY

3-2. 90-FT. BOAT; DEEP-WATER, 10 1(n., RUDDERS ALMOST OUT OF WATER

.3-3. 90-FT. BOAT, DEEP WATER, 10 FOREDECK. FLOODING

3-4. 90.-FT. BOAT, DEEP WATER, 10.9 Kn.:FOREDECK FLOODING

3-5. 120-FT BOAT, DEEP WATER, .12 Kn.,. FOREDECK DRY

3-6. 120-FT. BOAT; SHALLOW DRAFT' (5 FT.), 5.7 Kn.

3-7. 120-FT. BOAT, SHALLOW DRAFT (5 FT.'), 8.5 Kn.

4. MANOEUVRING TANK

The tank has main dimensions of 400 ft. x 200 ft. x 12-ft depth. Pneumatic wavemakers are being installed along the 200-ft. side. There is a 38-ft. high observation tower,

from which models can be radio-controlled, and photographic records of turning paths obtained. A prototype wavemaker has been installed in the main experiment tank and is now in

every-day use. The wavemakers in the manoeuvring basin will allow investigations to be carried out at various ship-to-wave course angles, and also manoeuvring in waves.

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Comparisons are to be made between smooth water turning paths in the manoeuvring tank and those obtained on

an analogue computer using the stability derivatives from the oscillating model mechanism.

If the absolute accuracies of the two methods

compare favourably, many of the tests now carried out in the manoeuvring tank will then be transferred to the computer, although each facility will continue to have an advantage in some particular phase of the work.

The following illustrations show the manoeuvring tank, some model arrangements and the results of some

particular tests.

4-1. THE MANOEUVRING TANK UNDER CONSTRUCTION, AND COMPLETED

4-2. MODEL SET-UP FOR RADIO-CONTROLLED MANOEUVRING TRIALS 4-3. RADIO-CONTROLLED MODEL BEING TESTED

4-4. CLOSE-UP OF RUDDER CONTROLS

4-5. TYPICAL RATE OF TURN RECORD

4-6. RATE OF TURN PLOT FOR A DIRECTIONALLY-STABLE SHIP

4-7. RATE OF TURN PLOT FOR A DIRECTIONALLY-UNSTABLE SHIP

5. WATER TUNNEL

This has proved to be one of our most useful

facilities for investigating a wide range of problems under controllable ambient pressure conditions. The tunnel was built under contract, of stainless steel, the design being made to the laboratory specifications. It was installed by N.R.C. personnel under the supervision of the Ship Section and has been in constant use now for five years.

There is a working section 20 in. x 20 in. x 80 in.

in length, access to which is readily made by the use of quick-release clamps. For example, a propeller can be changed in one

or two minutes without lowering the water level, the pressure at the access port being brought to atmospheric by means of reducing pressure in the dome.

Page. -.9'. MB-251

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-Page -.10 MB 251

For any flow rate the velocities at any pos the working section are very nearly constant, and the is considered satisfactory in this respect. Of cours velocity distributions can be produced for particular The maximum water speed in the working section is 40 and the minimum ambient pressure 120 lb./ft? absolute

The main impeller is driven at 1500 r.p.m. 75-h.p. motor, and the test propellers in the working usually 8 in. to 10 in. diameter, may be driven up to r.p.m. with a 15-h.p. motor. The propeller dynamomet measure thrusts up to 185 lb. and torques up to 30 ft A three-component balance is also available measuring forces and moments on test bodies. At the some interesting work is in progress in connection wi dimensional hydrofoils, and cavity flows.

5-1. TUNNEL WORKING SECTION

This illustration shows a special speed log set-up for calibration tests.

5-2-1. DIAGRAM SHOWING PRESSURE TAPPING ARRANGEMENTS ON AN

APPENDAGE

Pressure measurements were made with the appendage on a model both in the experiment tank and when mounted in the water tunnel. The device was also examined under cavitating conditions in the tunnel. The good agreement between tank and tunnel pressures is shown in the next illustration.

5-2-2. SOME TYPICAL PRESSURE DISTRIBUTION RESULTS

The full line is as recorded in the experiment tank and the crosses are from the water tunnel results.

The following eight illustrations, 5-3-1 to 5-3-8, show an investigation into rudder performance which was part of a special design study.

5-3-1. PRESSURE-TAPPED RUDDER MODEL

This shows the rudder mounted simulating part of the hull. The upper section cover plate. The fifty plastic the tapping holes can be seen coming up

in place on a plate plate is the.Working tube connections to to a connector panel, ition of tunnel e, special projects. ft ./sec. by a .section, 3500 er can .-lb.

for

moment th

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twoPage -MB-25l

5-3-2. RUDDER ON HULL PLATE BEHIND PROPELLER

5-3-3. RUDDER AND PROPELLER CAVITATION

This shows port and starboard views at a number of rudder angles for a high-speed condition. The cavitation is most impressive to watch as it expands and collapses explosively

at high frequency. The rudder is offset a little from the propeller and the hub vortex can be seen to pass the rudder at the lower angles; it becomes part of the rudder cavitation at

the larger angles. Some of the propeller trailing tip vortices also end on the rudder as they pass. Such phenomena as these are most interesting to see from normal projections of

high-speed movies.

5-3-4. RESOLUTION OF PRESSURES INTO RUDDER FORCES

This diagram shows how side forces perpendicular to the ship's centre line plans can be obtained bY simply- plotting pressures on the centre line projection of the rudder, and then integrating..

5-3-5. RUDDER FORCES

These are forces normal to ship's centre line plane as-measured in the experiment tank. The crosses are points obtained from integrated tunnel pressures merely to establish that the order of the tunnel modelling was reasonable. The

actual rudder forces are also composed of viscous fotces and these were not brought into the tunnel result calculations. 5-3-6. RUDDER TORQUES

Remarks similar to those for the previous illustra-tion also apply here.

5-3-7. RUDDER BENDING MOMENTS

These have been calculated, using the tunnel pressure results. The best rudder having the smaller bending moment was able to produce the same ship's turning force.

5,3-8. DEPTHS OF CENTRES OF PRESSURE

' The following two illustrations, 5-4-1 to 542,; show . the test arrangements used for propeller tests with a'SiMu-l'ated

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5-4-1. PITOT TUBE WAKE SURVEY

. The,pitot rake is the same as was shown earlier for examining the-boundary layer on a model in the towing -tank, as also are the automatically--operated connector valve,

pressure transducer, and recorder shown in the

foreground-5-4-2. HULL PLATE WITH WAKE GENERATING BARS

The bars shown on the, bottom left-hand side of the plate produce ,a wake corresponding to that of the b'oundary

layer MeasUed on the model..

-5-4-3. BOUNDARY LAYER IN TANK AND TUNNEL

The spots show the velocity distribution as obtained in the tunnel as an approximation to that measured in the tank,

shown by a full line. The behaviour of the propeller in this wake distribution was then observed.

Propeller cavitation inception diagrams are drawn by observing the speed of advance coefficient (J value) and cavitation number when various occurrences take place. The

following three illustrations are examples of cavitation

dia-grams. More recently the use of a cavitation number based upon the resultant velocity at 0.7 radius (ccr) has been dropped in favour of one based on circumferential tip speed

(0T) That based upon free stream axial velocity (ccv) is

still also used.

5-5-1. CAVITATION INCEPTION DIAGRAM

The sloped curved grid lines are values of constant

ccv

This particular diagram shows the demarcation lines of face and back cavitation for cavitation numbers below which these phenomena occur. The ship goes down the trajectory shown as speed increases and is in a safe region.

5-5-2'. CAVITATION INCEPTION DIAGRAM SHOWING THRUST LOSSES This is the same type

of

diagram as in the previous illustration but with the additional thrust loss information

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M-251

5-5-3. CAVITATION INCEPTION DIAGRAM ASTERN

The cavitation characteristics for astern conditions are not usually investigated, but were considered in this

particular case, The results indicate the early occurrence of cavitation when reversing, i.e. cavitation commences at high cavitation numbers under these conditions.

5-6. TYPICAL PROPELLER DESIGN DRAWING

The laboratory is well advanced in the fields of propeller theory, design and experiment, having been involved in many design and research projects during the past decade. A number of computer programs based on the most advanced

propeller theory are available. The effects of heavy loading have been studied by the laboratory and improvements to design methods have been and are continually being made. Form plans

can be supplied, to form the basis for construction plans, taking account of cavitation, strength and any special features required of the propeller.

The illustration is given to indicate the essential features for defining propeller geometry. These are a list of main dimensions and geometric coefficients including radius of gyration, and expanded sections plan showing axial thickness,

and a table of axial back and face offsets. The projected and profile views can be adequately shown in small size on the plan. The laboratory has used and advocated axial offsets for defining propellers for many years, and they are increasingly being used

internationally by propeller manufacturers. The table of off-sets can be used as a standard when checking full size propellers with an appropriate machine. They are also used on the same

basis in constructing the propeller model. The offsets are based on calculating those to the section chord lines and then correcting to the face and back with differences measured on full size section drawings made on stabilized plastic paper. These section drawings are also made available to the manu-facturer for construction and edge checking purposes.

Further to the form plan, it is only necessary to specify details of material, hub internal arrangements, and tolerances. This latter item is successfully receiving much attention by Canadian authorities.

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Page - 14 MB-251

5-7. PROPELLER OPEN WATER CHARACTERISTICS

These show thrust and torque characteristics from the water tunnel, in this case, with the effect of changing cavitation numbers. Cross plots from the thrust curves have been shown previously as loss of thrust information on the

cavitation inception diagram.

5-8. A PARTICULAR PROPELLER AT TWO CAVITATION CONDITIONS

This shows typical cavitation patterns as developed beyond the half full speed condition for a particular ship for

a constant pitch propeller. As power is increased up to full power the tip cavitation extends down over the back of the blade.

5-9-1. SOME TYPICAL PROPELLER CAVITATION WITH A CONVENTIONAL

HUB AND WITH A DIVERGENT CONE

This approach for distributing the vorticity over a wider cylindrical section of the slipstream for a particular

case was devised by a member of the laboratory staff. By this means the hub vortex is prevented from forming. Another method

for achieving this result, depending on the design details is, when required, in general use in the laboratory.

5-9-2. A PARTICULAR HUB VORTEX CAVITATION DIAGRAM

The results here refer to the propeller of the pre-vious illustration. A large increase in speed is obtained before the hUb vortex is formed. In this particular case it would only occur at speeds well beyond the top speed of the vessel.

5-9-3. THE EFFECT OF DIVERGENT CONE ANGLE FOR A PARTICULAR

PROPELLER

This diagram shows the trend of increasing cone angle to improve performance, again in this particular case.

5-10. MODEL.CONDENSER SCOOP RESEARCH

A model condenser inlet and outlet are mounted into the side wall of a small water tunnel. The circuit-piping is

completed and a flow valve and venturi are incorporated.

The scoop and outlet characteristics are examined by varying tunnel velocity, corresponding to ship's speed, and for different circuit flow rates. A check and extension of published scoop information was being sought in this particular case.

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MB-251-6. MAIN. SEAKEEPING FACILITIES

pneuma.PY-etrlat,

a

pable:of

producing 2t.. high. waves at frequencies up to one cycle per second, ha8 recently been fitted at the end Of the .main experiment.tank. 6-1. PNEUMATIC WAVEMAKER DOME

The waves are produced by subjecting the tree surface inside the dome alternately to pressures oscillating above and below atmospheric from the delivery and suction sides of a

50-h.p. axial blower driven at constant speed by an-a-c. motor. The frequency control is made by adjusting the pee. the

flap valve which exposes the dome to one side or other of the

fan.

Amplitude of the wave is reduced, as necessary,

by

opening a:bypass valve in a cross, connection: between the -delivery and suction pipes.'

6L2. REGULAR WAVES TRANSMITTED ALONG TANK

6-3. LARGE INSTRUMENTED MODEL PITCHING IN WAVES

Until recently, in the absence of larger facilities, most of the seakeeping tests have been carried out using

special small models 5 ft. to 6 ft. in length.

It is expected that there will be little or no need henceforth for these small models.

7. TEMPORARY SMALL MODEL SEAKEEPING FACILITIES

-This tank was constructed to dimensions 150 ft. x

26 ft. with 5-ft. depth of water. The tests carried out have been mostly on rolling characteristics of vessels and the

capabilities of flume stabilizers. Comparisons have been made with results on the same model as tested in Ottawa and

in a United States tank. The agreement was fair and, as a result, the United States laboratory decided that the refined techniques it was using should be adjusted for more accuracy as accredited to the Ottawa results.

. .

On another occasion,, results- on a small model

-at-. ,.

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Page 7 16 MB-251

good comparison. Such comparisons for other tests, have been carried out from time to time over the past decade or so and are a means of improving test techniques and also of inspiring,

confidence in everyone concerned.

7-1. GENERAL VIEW OF TEMPORARY SMALL SEAKEEPING TANK 7-2. CLOSE-UP OF PADDLE-TYPE WAVEMAKER

7-3. STATICALLY AND DYNAMICALLY BALANCED SMALL MODEL FOR SEAKEEPING TESTS

7-4. RECORDING APPARATUS FOR MODEL MOTIONS AND WAVE DATA 7-5. SMALL MODEL WITH ANTI-ROLLING TANKS INSTALLED

7-6. GEOMETRY OF A PARTICULAR ANTI-ROLL TANK PROPOSAL 7-7. EQUIPMENT FOR BENCH TESTING ANTI-ROLL TANK MODELS

7-8. CLOSE-UP OF THE OSCILLATING CRADLE

7-9-1. ANTI-ROLL TANK CHARACTERISTICS

This shows the effect of depth of water on water transfer in a particular configuration.

7-9-2. ANTI-ROLL TANK CHARACTERISTICS

This shows the benefits, in a particular case, of removing weirs and nozzles as they were planned in a first proposal.

7-10. FLUME STABILIZING TANK IN A MODEL

7-11. MODEL ROLLING IN WAVES SHOWING RECORDER CONNECTIONS

7-12. ROLLING RESPONSE CURVES SHOWING EFFECT OF BILGE KEELS

In this particular case the bilge keels were shown to be very effective.

7-13-1. ROLLING RESPONSE CURVES SHOWING THE EFFECT OF

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MB-251

7-13-2. ROLLING RESPONSE CURVES SHOWING THE ADDITIVE EFFECT OF BILGE KEELS

In this particular case the.. benefits bilge keels

Ore superimposed on the benefits due to tanks alone, as shown

in

the previous illustration.

7-14-1. ROLLING RESPONSE CURVES SHOWING THE NEGLIGIBLE EFFECT. OF BILGE KEELS IN A PARTICULAR CASE

7-14-2. CORRESPONDING DECREMENT CURVES WITH AND WITHOUT BILGE KEELS

714-3, TANKS ARE EFFECTIVE IN A1PARTICULAR CASE WHERE BILGE

KEELS WERE NOT

7-15-1. ROLLING SPECTRA, ETC. FOR A STATE 6 SEA

This diagram shows the next stage to be cohsidered for obtaining useful information from the rolling response data of the previous illustrations. Similar processes can be carried out using pitch and heave response factors, etc. It

is most interesting to observe that the response factor roll angle

g

i.e.

a , for any particular vessel and frequency

wave slope'

is constant even up to large rolling angles. This fact enables statistical conclusions to be arrived at for any

particular vessel at the appropriate heading in a given sea.

Until recent years, all the classical experiment work on seakeeping has been carried out in regular waves, the procedure being to send down a train of waves of constant

frequency and height and then to repeat the process at another frequency and/or height. Because of the idealized nature of these experiments the results have always been subject to the criticism of lacking reality. The statistical approaches that have been applied in recent years have now supplied proven methods for making use of regular wave experiment data to obtain behaviour predictions in real, i.e. irregular seas. Previous reliable experiment results can now be applied with confidence for such predictions.

In at least one establishment, for each train of experiment waves the frequency and height of successive waves is adjusted; thus the model is subjected in quick succession to different wave heights and frequencies. Such experiment

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Page - 18 MB-251

methods have the potential, of reducing over-all experiment time but with the probability of loss of accuracy; the result-ing seas cannot be considered as a realistic representation of a true sea.- The modelling of actual sea conditions for a given period is theoretically possible and in the next few

years may actually be carried out. Although this may be

considered desirable in some respects, it will only have limited scientific importance.

In summary then, it is considered that reliable statistical results for actual sea conditions can now be obtained from model test data in regular seas.

dE

The diagram shows the spectral curve 5731 as proposed

by Newmann for a fully developed state 6 sea. There will be typical sea spectra for any area at a given time of the year and

and such information is being collected throughout the world. Following on from the amplitude spectrum, there is a wave

dE,

slope spectrum

Ti7r,

the high frequency waves having the greatest

slopes.

The tolling magnification.factor for the particular vessel

(0/a)

is shown with its peak at the natural .damped'

frequency of the vessel.

Applying this response operator to the wave slope dE,

spectrum, the rolling spectrum Ti.-(t is obtained. The rolling spectrum has its peak again at the natural damped frequency of the vessel, reflecting the peak of the magnification factor. A vessel rolling is a very good filtering device, its motion being a magnified reflection of the waves at the vessel's

natural frequency, and the large rolls will be at this

frequency. This magnification is a result of the very small amount of notion damping on the hull. The effectiveness of stabilizing devices is to provide some damping where almost none previously existed, and the result is to cut down the peak of the magnification factor resulting in small roll

angles. The actual wave lengths (Lw), in feet, are also shown

on the diagram.

By, finding the square root of the areas of the

rolling and wave amplitude spectra, various statistical results may now be obtained.

(21)

Page - 19 WB-251,

7-15-2. SOME .STATISTICAL RESULTS FROM THE SPECTRAL DIAGRAM FOR A PARTICULAR VESSEL IN A STATE 6 SEA .

Some of the important roll angle and wave height statistics, such as the most frequent, average of the one-third highest, highest expected in 1000 waves, etc., are shown on this diagram, together with the percentage of

oscillations expected in any particular range of roll angle and wave height.

8. FULL SCALE TRIALS

The laboratory has always been active in checking perforMance predictions and examining problems on ships at

sea.

During sea trials, measurements are made of speed, power, shaft speed, fuel consumption, turning paths and rates of turn, rudder angles, steering gear ram pressures, vibra-tions, rolling, pitching, heaving, and towing forces.

Many reports concerned with the analysis, and comparison with experimental and theoretical predictions, have been issued. Equipment is available for recording all of the above items.

Torques can be measured on shafts from 11- in. u

to 18 in.

diameter,-8-1. TORSION METER ARRANGEMENTS

The next five illustrations, 8-2-1 to 8-2-5, show the arrangements for a special investigation into the hydro-dynamic performance of a ship's condenser cooling system. The work was correlated with model tests carried out,in place on a ship model in the main experiment tank, with the water tunnel tests previously illustrated, and with published data.

8-2-1. FULL SCALE PITOT RAKE ASSEMBLY AT CONDENSER sINLET 8-2-2. FULL SCALE PITOT RAKE ASSEMBLY AT CONDENSEOUTLET

8-2-3. FULL SCALE PITOT TUBE CONNECTIONS ,

(22)

Page - 20 MB-251

8-2-5. SOME VELOCITY DISTRIBUTIONS IN THE INLET PIPING SYSTEM

8-3. HIGH POWER STROBOSCOPE AND FLASH EQUIPMENT FOR PROPELLER

VIEWING

This equipment has been recently acquired for making propeller cavitation observations at sea which will, it is

expected, provide Importantscientific information regarding their detail performance. This will be important not only for its inherent value but also for critically examining existing model experiment and theory techniques.

9. COMPUTERS

These have been installed for general use by the Division of Mechanical Engineering and are an important and

essential aid to the operations of the Ship Section (essential, in that many calculations and investigations could not other-wise be carried out).

The analogue computer has been used for preliminary manoeuvring and seakeeping simulations and many new investiga-tions are planned.

9-1. ANALOGUE COMPUTER WITH DIGITAL CONVERTER; DIGITAL

COMPUTER IN BACKGROUND

9-2. CONTROL PANEL FOR MODEL MANOEUVRING SIMULATION

The operator can simulate the manoeuvres of vessels from a panel of this type, being able to position hydro plane or rudder angles at set rates, and observe depths, trim angles, etc., or transfer, advances, course angles, etc.

9-3. DIGITAL COMPUTER

These have been useful for carrying out many of the routine calculations normally carried out on desk calculators, but at much higher speed. Many programs in this connection have been written in the laboratory. New, and otherwise impossible, calculations, in particular for propellers, are also carried

out. A recently revised program for calculating ship

hydro-static particulars is available.

An analogue digital converter has recently been fitted to connect the analogue and digital machine, and the theory for making best use of the resulting hybrid machine is now being developed.

The equipment is available for direct use by Canadian industry.

(23)

MB 193 MB-221 MB-225 MB-226 MB-227 Page -MB-251 ACKNOWLEDGEMENTS

Recognition must be given to the Royal Canadian Navy, Department of Transport, other Government Departments, and

private companies, who make use of the facilities, and without whose interest most of the work illustrated here woUld not have been possible.

The author is most appreciative of the enthusiasm of the staff of the Ship Section in carrying out their work.

The report has been produced with the encouragement of the Director of the Division of Mechanical Engineering.

SELECTED OPEN DISTRIBUTION REPORTS

"The Velocity Distributions Round

Elliptic

Sections . Due to Thickness and Angle of Attack".

G.J. Mainwood. October 1956.

"Cavitation Tests of the 3-Blade Kamewa Controllable Pitch Propeller". J.S.C. Straszak. December 1959. "A Simple Approach to the Mathematical Ship Form".

P.A. Hamill. September 1960.

"Computing Effective Powers and Associated

Coefficients from Ship Model Resistance Tests". P.G. Morel. September 1960.

"A Program for the Calculation of the Hydrodynamic Pitch Angles of Propellers with a Bendix G-15 Digital-Computer.

C.G. Benckhuysen. August 1961.

MB-228 "The Calculation of Propeller Induction Factors: An Intercom 500 Subroutine for the Bendix G-15 Digital Computer". P.A. Hamill. August 1961. MET-257 "Wax Model Construction". R.J. Peters.

(24)

Page - 22 .

MB-251

MB-231 "Optimum Length and Illickness of Propeller Blade Sections from Cavitation and Strength

Considerations". S.T. Mathews and J.S.C. Straszak. April 1961.

MET-285 "Water Pressure Transducer". L.I. Kawerninski. April 1961.

MB-237 "A Program for the Calculation of the Circulation Distribution of Propellers with a Bendix G-15

Digital Computer". C.G. Benckhuysen. August 1961. MB-250 "Programs

'for

Calculation of Hydrostatic ParticularS

of Ships", Ruby C. Denison. January 1963.

GENERAL REPORTS

The National Research Council of Canada Forty-Fifth Annual Report for 1961-62.

Review of the National Research Council, 1962.

Quarterly Bulletin of the Division of Mechanical Engineering and the National Aeronautical Establishment, December. 1962.

(25)
(26)

GLUE PRESS

WITH LARGE

MODEL

(27)

. 13 , ,s. Vo 4 ,,. \ ' '1/4 ' ;Vt., .% Ns: ,:s-4s,,',

--=

,Ic\I

, s, \ \ \ . \ -,. v. T'''' s MODEL PROPELLER SHAFT BOSSINGS

BEING CUT

ON A STANDARD MILLING MACHINE N3 I

(28)
(29)
(30)

FIG. 1-6

MB- 251

(31)
(32)
(33)

=AI

TOWING CARRIAGE

WITH

PROPELLER

OPEN WATER BOAT

N141

FIG. 2-1

(34)

r-7r-1r

"

C

(35)
(36)

41. rs / /0 0 ,. j , jt

MODEL SELFPROPULSION

DRIVE MOTOR AND DYNAMOMETER

If:

(37)

4-Beam moulded

Displacement beam B.

Draft forward, at Section 20

Draft aft, at section 0

Mean draft, at +Section 10

Volume of displacement

Displacement

L.C. B. aft of fore perpendicular

Speed ci = = 3.3585ve

Force W = gpV 64.040 V,

Torque CI = gpr.. = 64.040 Vr

Shaft Q gosv-usi = 340.33 Viv

speed Power P=W .66045 vr

4.90069

V4 _117. 699

576.807

13853.1

67889.7

332,706

FORM PARTICULARS-

I

Type Scale Condition 4,00

Ship

Customer Neigh SHIP MODEL

Length between perpendiculars Lep 400..02 ft

ill

199. 875 . in

Length on load waterline Lim 400600 ft Ism _1994_864

Displacement length Lw -400. 00 ft lw 199.8614. in

..

Length of parallel middle body L. ft I, 4. in

A ft ft _ 22-. 516

22.516

ft

22.516

ft

325,17k

_9290.7 r

202.67

ft

Area of displacement waterplone Aw ft t

C.F. aft of fore perpendicular

Transverse M.I. of waterplane ft.

_21.8504

1m 2.08214.1 *107lb

L 43199 .109

ft lb

41.0406

min-1

780910.06

hp

yr:8.29251

fte-5 68.7657 ft z

4728.72

ft. 223608 ,107ft4

vr

2.69651.

106ft.

FIG. 2 MB- 251

24.

0168 Model No V = 5.6721 Vr w = 62.364 4 = 62.364 q4,13 7r) 5.672117;:(11 0 353.74 yr bw in in

11.250

A, 11. 250 in

11. 50

23.473

_ ft3 1464* 71 lb 101.4265 in

29,328

108.0

ft2in 1469211 fell V r _ 2 f 8.6322 ft

8.1981

171r

.

vr

_67.2077 ft' voir

39.7188

-77 V

Wetted surface

30,228

it!

52.405

ft,

REFERENCE QUANTITIES

Calculated by R. D. Date

Jan. 25/63

p 1.9384 (FW) = 1.9905 (SW) lb ft' sect Checked by C. G_B Date

Jan. P5/63

9.59779

ft sec'

463.87

lb

14191.34

ft lb

_3.35210

sec"

(38)

FIG. 2-4-2

FORM PARTICULARS 31

MB- 251

Condition

4001 Shin,

Modsl No.

Note: Ho is draft

at sect . 10 from base line.

Ax maximum section area at section 9

IT Transverse Beyer

v

ft. HD u

22.516 ft

Ax

249.20 ft!

LW 2 2111L 8

5.817

Ca V Z

0.6330

VIA) LD BD HD LVBVIIVI

72

I :Ca a

0.6507

Hq * HD * (L32711

Cps

, A 1 A

r

VIA 1-D pix 1..1p.m wpa

BD

0.8295

BD

.

BV

,

2.533

BV a V V3 HD HT S

6.392

LD I-

,

7.013

V213 SD By Au It

v

Ax.

ii Z

0.2642

C w 2 Avi 0 . 714311-LD BD CM BD HD g B:VHV

"727

IT a PAT co .1538 Ax ITV TiVi Lp L.C.B. from LD forward

50.67

LD LD Trim % L.0-20 LD BD = LOD HD 3 BDHD LD AX Calculated by

R.. Denison

Date

.Tan. .25. 1963

'Checked by C G. B

5-1-&3.

(39)

rt.) CM , sr .104. 0 COW. '-1 1

AntursommunnimmoramodorARELO:

,

i

I

PrfigillairMlierfAIRRUVRIFATI

600

I'

12 . 1 3 91 3' Z

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MU NAM

epiii,,

1

ba %

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WINIMINUMIN

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i

030'11W1111111"111111111111111114t

bt. 03

I,

93 0

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a.

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MUIMIlik

d AA

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i

1

ni

Iti k A

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'k,

, Pi 0 a 01

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Prilf1111111111qPIPPINOMII

0

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.

AL

A

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0

.

I\

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U>

Q) 6 -6 ILIU

a

(40)

s 111 (\IN Ocsr, 17..m CO a)

04(0

ico. sgt >II> lig .41 ci 0 0 ci

111111111111111111111111111111111111111111111111

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Min

immommum

mumkmamehiammOmms mom

mommumm

IMOMOMMMIBINESIMISCOAMOO MOM=

IMMIMMIIMMI

011011110611113062POIONNE MOM

11111111111110

MIMMONIMIOWIOMMOMIVENMEMOOMMI

IIIIIIIIIII

11111111MINgiamMiallannlIMMOM

IMMINIMMIO

MOMMIMI011111111

mum=

mmmmmmmmmmmmmmmmamamhqnammmm

1111

ro 1-..

2

m

'a

m m m

0

X

4

I

6

_.1

.

a

0

Q

Z

. 41 x

0 " 0

C7)

00J

m a_tr>

z

w (LI

>

x

.0

8.

Z

0

w

o

w

a

z

u)

(41)

4.0

Pxv

x

NON- DIMENSIONAL SHAFT ,SPEED

-VS.

SPEED 'OVERLOAD DIAGRAM

'4

0.66853 0.637 0.622 ,0591 0.560 V .17 0.498 0.435 0.373

00

11111111INSMININI

3.5

Nil 2(SHIP) .41.04 RPM. mermagrin

TRSHIP) =2785 KN.

1111

.025018.1111111

1111111111101M1111111111

1111111110C1111111111111111

11111111RIMINIIII111111111

1111111/3811,111111111111111

Immeafilumprommillgi

111111111111111111111111111

1111

111111111

11111111.41111111111

11"

los 3.0 2.5 ZA 1 0.5 1.0 15

(42)

FIG. 2-4-6

MB-251 9 8 7 6 5 4 3 2 15(SHIP) .1.781 x106._H.P. (SHIP) =27.85 KN.

TRIAL CONDITIONTION

*Or

ro

PfAi.

00000-0'0

000

1101111k11,

,..N111111111E1111111

7%

OVERLOAD 10% 2O% 0 0-5 1-0 PEv 2 v X 10

NON-DIMENSIONAL DELIVERED POWER VS.

SPEED OVERLOAD DIAGRAM

I5 0.684 0:653 0.637 0.591 0.622 0.560 0.498 0.435 0.373 HIP II I

(43)
(44)
(45)

MODEL WITH

PITOT RAKE WITHOUT PROPELLER

F 16. 2,71

(46)

FIG. 2-7-2

MB-251

cv

r

4

15, "3 61.-= r. I I.E...1

4

5

(47)
(48)
(49)
(50)

Q9 0.8 0.7 0.6

> 0.5

40.4

>

0.3 0.2 .0.10

a

,PITOT WITH PROP

PITOT WIT ; WAKE METER SELF P 0.1

0.2

0.3

04

o.5 0.6 0.7

08

TYPICAL RADIAL VELOCITY DISTRIBUTIONS

0.9,

1 0 Xc ROPUILSION-P. ROUT PRO

(51)

DIFFERENTIAL PRESSURE TRANSDUCER

FOR USE IN

WATER (HIGH SENSITIVITY)

(52)
(53)

STREAMLINE HOUSING

FOR

UNDERWATER CAMERA

COMPONENT PARTS

SET UP FOR

VERTICAL VIEWING

FIG. 2-10

(54)

FIG. 2-11-I

MB-251

PLAN VIEW

t. OF NOZZLES -APPROX. 12° FORWARD

OF THE RIGHT ANGLE TO SHIPS t

FROM DWG. NO. 58 -63/10 POSITION OF PUMP SUCTION APPROX. 34 SHIP". r1APPROX.27" MODEL 145 SHIP 72.5" MODEL -0-6.- 0" SHIP 3"MOD 17'WL SHIP 8.5" WL MODEL PART ELEVATION PUMP SUCTION POSITION OF JET NOZZLES 5' -7.5" SHIP 17.813"MODEL STBD. JET NOZZLE F. P F. P.

DIAGRAM SHOWING INLET AND OUTLET POSITIONS OF BOW MANOEUVRING JETS

N.B. NOT TO SCALE

(55)

41r-Gr°V--

6:

MODEL PREPARED FOR BOW JET TURNING TESTS

FIG. 2 -II- 2

(56)

FIG. 2-11-3 MB-251 i0000 9000 8000 7000 6000 -3 5000 Cr X 4000 3000 2000 100 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 I THRUST OF 3.5 TONS 0.9 TD 0 clJ 4:o7N ./ A 0.8 THRUST OF 5000 LB. 2 , :zo '' 0 A: o A. (-1 A 0.7 U,0 f=

a

cc $.5 o 0 $' Tr 0 0 0 4.. 4 A.- 4,-..44.. . A. .. . 0.61_ cn m cc x 1-0.5 A`r

-Add

o A

'"'

A. 0.4 -.11111111111111111,-1 1

olor

14-co 42 Q4. lx*-.::. c, .c

illprop

111111411

1000 2000 3000

MASS FLOW, 0 (LB./SEC.)

JET THRUSTS FOR GIVEN FLOW RATES

(57)

1 1 I. 0 0 0. 0 0. 0. 0. 300 400 T, TIME IN SECONDS 500

SHIP TURNING ANGLES FOR GIVEN JET THRUSTS

LIGHT CONDITION, SHIP STATIONARY

600 700 6 -90 5

Ell

592 9.87

/

703 00'

/

I 66 .77 = 80 '.... ...e. 1107 66

17

- 7 0 RESULTS 40 ° ARE EXTRAPOLATED BEYOND

/

04' ..."

/

..." .-6 0 VS5 .0' ..

Millnill

9

le

0 -° El MEG.)

ct.

f..°0°. 7 40

10"°

e

0 -

AIOJIIIIIIIMPPPPP-

El-loist

-30 5 i..S 01 -./11 .

UU

00/ 'it ...° .- 2 0

-I

a -(0 0 WW1 ...

Pillill

_ _

(58)

-DIRECTIONAL

(59)

SHALLOW DRAFT TANK

(60)

90-FT. BOAT,.

DEEP WATER,.

10 KNOTS NOTE

RUDDERS ALMOST

OUT OF

WATER

(61)

90-FT. BOAT, DEEP WATER, 10 KNOTS

(62)

-411T41:4 !It , .0.

90-FT.

BOAT, DEEP WATER,

10.9 KNOTS

EXTREME FOREDECK

FLOODING

"r1

(63)

-120-FT.

BOAT,

DEEP WATER,

12 KNOTS

(64)

120-FT.

BOAT,

5 FT. DEPTH,

(65)

120-FT.

BOAT,

5FT. DEPTH,

(66)
(67)

o

MODEL SET-UP FOR

RADIO-CONTROLLED MANOEUVRING TRIALS

FIG. 4-2

(68)

FIG. 4-3

MB- 251

" .2.0%atit. -'-'""r"*,

"--

-,-',4,°° _ f." -'boRn. .4.

RADIO-CONTROLLED MODEL

BEING TESTED

' -"Ss-4-.47"r.

-"Jr

(69)
(70)

111111111111111111111 AIL AIL

ilk

ANL A% AL. dirb 401% 4011r. 416.

TYPICAL RATE OF TURN RECORD

(71)

15 PORT 10 71/2 5 3 or"

FIG. 4-6

MB -251 RUDDER ANGLE 3 5 71/2 10 15 STARBOARD

TWIN SCREW VESSEL

SINGLE SCREW VESSEL WITH

RIGHT TURNING SCREW.

(72)

FIG. 4-7

MB-251

Zr"

#19/

o TWIN SCREW VESSEL

SINGLE SCREW VESSEL WITH RIGHT TURNING SCREW

cr a.

RUDDER ANGLE

71/2 10 15

STARBOARD

RATE OF TURN PLOT FOR A DIRECTIONALLY-UNSTABLE

SHIP

15 10 71/2

(73)

oozes,.

al.Jli Aywa.s.... - /- : i '''. 1

'

r -1'7 ,-.1:. .. - .. 4, .:L.11nat.c.r ISM

TUNNEL WORKING SECTION

,

v3r-FIG. 5-1

(74)

FIG. 5-2-1

MB- 251

PRESSURE TUBE

ADAPTER PLATE

9.1 IN.

Of 20-IN. X 20-1N. WORKING SECTION

DIRECTION OF

FLOW-.PRESSURE TUBING TO

MANOMETER BANK

SECURING BLOCK

ALUMINUM WINDOW

LOCATION Of STATIC PRESSURE TAPPING

DIAGRAM SHOWING PRESSURE TAPPING ARRANGEMENTS

ON AN APPENDAGE

(75)

0. 0. 0 0. 0. 0. SECTION J 1 8 MODEL CAVITATION BASIN TUNNEL X 6 4 2. j...---.. )1e 0 ' x 9 10 9 8 7 6 5 4 3 2 0

SOME TYPICAL PRESSURE DISTRIBUTION RESULTS

(76)
(77)
(78)

FIG. 5-3-3

MB- 251

esS

TRAILING EDGE OUTBOARD

15° -30° 45° ',Ate

-RUDDER AND PROPELLER CAVITATION

00

(79)

RUDDER SURFACE

RUDDER AXES

ds COS a 2

FORCE NORMAL TO SURFACE p ds

COMPONENT IN DIRECTION OF Y g p ds COS a p dx

X-AXIS

0160110

RESOLUTION OF PRESSURES INTO RUDDER FORCES

FIG. 5-3-4

MB-251

1°t4

(80)

FIG: MB -:251' 250 200 CI)

8

IX 160 50 oo 10 20 30

RUDDER ANGLE DEGREES

RUDDER FORCES

(81)
(82)

FIG. 5-3-7

MB 251

i-z

2

0

co 0130 400 500 X

TRAILING

!III

EDGE OUTBOARD TRA1U NG

JII

EDGE INBOARD

I

40 30 20 10 0 10 20 30 40

RUDDER ANGLE DEGREES

RUDDER BENDING MOMENTS

RUDDER

B _X

(83)

.8

.2

DEPTHS OF CENTRES OF PRESSURE

Id FIG. 5-3-8 MB- 251 p. I X RUODER RUDDER I B C I I ft

I

*

X oX It It

*

I TRA1UNG EDGE 1 OUTBOARD I TRA1UNG I EDGE I INBOARD

6

Id Id

II-0

t

n. 10 20

RUDDER ANGLE DEGREES

(84)
(85)
(86)

FIG. 5- 4-3

MB -251 4T

IT

0 - BOUND PRODUCED I ODEL TION SHIP M FLOW DIREC BOUN ARY LAYER N WATER TU -0 NNEL. OAR" LAYER

0

2 4 6 .8 10 12 14 V (FT./SEC.)

(87)

a

24 20 16 . 8 7 a ON SPEED ON RESULTANT RADIUS OF OF ADVANCE PROPELLER c6 is( 1 . ac BASED R 2 CE BASED AT 0.7 .

fV0;121

mai

acv aC SPEED

-Kim=

OW"

IIPMeWlidal

111.1P,S/P9

JAMMIPEPO

AI__

411111

ANTIMplPd

a c . _

VAIVAIM

WAIII;WiriMil

roppAp-prow/

SHIP IN TRIAL

111%1

I W.4

mas N

Q6

CAVITATION

MAMMIIIIIpMlf

eNDITIO

_Mal

N ' ,,7,--111.P.-

I.'-Illawi=kit

i.%

_.iiid1110

_...0/1111111111111 H

/I

M M

IIIIINIVAII%,

111.Mr:

I

WariPIPI-trams=

0.7

wmParammourralrawara`-mp

0 CAVIT.T

,,,t,

INCEPTION

LimiLwitklio_.i.

AAfinAld

IMPP- /I

sialAP-L5 L4 13 12 1.1 W 9

9

0

1 al 1

_

...._

Mr

. 0.4 0.5

Arorrippri,,,

/AfAid

..2 IrArrAIAIMParrAill

TAParedroPpror

A

Ila

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/901111111

1.,...

0...0,,,_

, 0.9 10 I 1 DIAGRAM

/

CO 1 N) (.11

(88)

-10 9 8 7 6 I g. 71 as a a

-ON SPEED OF ADVANCE ON RESULTANT SPEED RADIUS OF PROPELLER IrY

e E. 1 IV 01 1 IV 16 13 10 7. CrCV 4 -3 as 1.4 1.2 1.0 . B-'''CR

,,n4

= ac BASED . ac BASED AT 0.7 P -e - 07

A_____

1/2 P Vog ,5,---CiR Crev

a.

CV

.----"---'..----,

____---.

\C-4k

TIP VORTEX AND BACK CAVITATION

4

Aerli-N

.

Arair

AA

isi

. . .A.,.., . .

t-' 1/

14/-11MPF

... , KNOTS

.

8/1 116.- IP IN ,__,.... .8 7 - a

MIWASW

ArArar

4 -, AL 1iN

-\

-

111Will.W.'-

---...PI .-fr et ,,_ 4L' - ' -_.../

FAlI.

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:

6:----et4 _A/ 4..- ....41140 ,

WArlar

Amor

- wrigr4

FA, Amy

III& A I 1 k/ri Ai, WA

VT

-N. N.

.\Kb-c

A

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-... ,,..

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r

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Pr

SS .04. , .. NI.

L.-O.

1_1*

11,11 "4111WII-.. .. ... B K cAvrArio START

AD1f_--9

I

_ FACE CAVITATION Q1 02 Q3

Q405

-CAVITATION (16 Q7 05 0.9 10 1.1 12 L3 J . .4

(89)

-LOSSES-I

bu ti5 0. Irj.t N 1110 -FIG. 5 -5-3 MB- 251 9

(90)

40101.1. 14102111.1.20 411411.11.A. e IP. AS Pap ma elin camp N. ..11. enies So elle re ma ea ono % FS. ea neer. nne n Fo bee DOM Cane ennead. Inane 11710 /...20 unn .0,0 44 mese.

10.-.0. eines00,401. Mae Lame

tallsbla lett S or new MO Or Neel nave 0, MOM. earn 07... Man co elneeir

OS 00 sen 1000 111:01 17:0'71 14100 00 M. 1110 ea all lei 10 In 01 1.S. el DO n.114 BO SS al.a. II. SS n 4 4 4141 .1 ar 1 ea Sttres Waft gle.+1 SO SO 74 411 SO 411 44. VI 10 00 ION .312 Mel 1SS. 111.111,412 e-a0

laneIR. Mops.

srsen104. meow.

RN elan Or ea

eet....1

Wenn Meow

1.0440

eon 01 0.111. ../1111 Vane 0101.04e

11.1.10. nine Oen Nen

A PAN al POW

110 Oil= al MI VI,

C.

1424.4

',U. oar nsnu sue Masa Or Fa Kneel 400

101 es L. OF

lute. men. nen..

1324 114.3.4 10 sunscreen .9. 11.1 ".. ,..= 1, LnrofFZ. an MO on Mel IS Ilene la e Ian .. ire ... -r-sx.14 In MOM Ma Ina

wax neren Foe

17, swan

31.47

WI/ INN VIA 121113

PI IOU LAI 04 47111 4,111 Vild BO/ 13011 MG VIM 11(C13 //14c 4aS 0.01 Fe s MEI 444 !T.

Lena rent ern

FO La net Del 00 ere ---"' - /2.-1 len sow

.

LIN 0011 ne ...: en Oa me .?.. ''''' : WO en pppr, pp pp.. gp ,,, NO MI .1 Mi n0 Pi .0417 MO ri.r :Z....M. ,...6.4- .... -.Ili -. -i.. OM WO 1. a. ... ...,.. ... 140002 en 00 See 4.2e /a ten or re-On 14101/6. n:rar. elm .2 .53,.., me se sr as or in Mere In an 01.1110 .. =Wan 1000 en -IMO WO We en

f

Ole eel fre Ire MEI 1134. 04101 asol. LT, 0.110 n. Me UM Sea en On ea on 121e. en 9.3 an I DO XI0 -aralli1111111111,1INJTMBIANAIII 0. 0010 Amirmiriummffm-MIWN=SM. M=AMM/11111. -"

110111111

I I

Awarlit/MaralrallEara.

MIA_

/511111a.r.,

An=

ArAire0,41

AWL"

X OA

'irfnmirk

X 041 X OA X O. 002 OS X OS Ora

TYPICAL PROPELLER

DESIGN DRAWING 121. I " 02 0411PM/ 61,1412 We 011110 afaa _07 ne 42. 011 OM .19 Ste 104 4. .1 1 _ I _ °- I 0114

(91)

3.5 0.70 2.5 2.0 1.5 1.0 0.5

PROPELLER OPEN WATER CHARACTERISTICS

FIG. 5-7 MB- 251 lo

P

4

mil

E

Oil

1 1

AL,

NA

111M

11

r SI

WARN

Elle

AKE

AI

E

PIM

II

11111

MM.

11101

ILI

IN

101

NM

KG

05

06

07

0$

09

10xKT 100x K 0.65 0.60 .55 .50

(92)

FIG. 5 - 8

MB - 251

HALF SPEED

HALF POWER

(93)

-CONVENTIONAL HUB

DIVERGENT CONE

SOME TYPICAL PROPELLER CAVITATION WITH A CONVENTIONAL HUB AND WITH A DIVERGENT CONE

J: 1.07; acr 0.27

FIG...5-9-1

(94)

1.0 09 0.8 0.7 0.5 04 0.3 0.2 01 Di v RGEN r CONE

op

1.1 12 1.3 1.4

A PARTICULAR HUB VORTEX CAVITATION DIAGRAM

_ .

FiG. 5-9

2 cra.

MB-25I

5.0 VA ADVANCE COEFFICIENT n 4.0 Po CAVITATION NUMBER cTcr 3.0

4 p

[i

SHIP SPEED IN KNOTS

(95)

= CAVITATION NUMBER

J 3 PROPELLER ADVANCE COEFFICIENT

a SEMI-ANGLE OF DIVERGENT CONE

INCREASING J

THE EFFECT OF DIVERGENT CONE ANGLE FOR A

PARTICULAR PROPELLER

FIG. 5-9-3

(96)
(97)

PNEUMATIC

WAVEMAKER DOME

,0

r

(98)
(99)

LARGE INSTRUMENTED MODEL PITCHING

(100)

v.,

(101)
(102)

FIG. 7-3

MB- 251

STATICALLY AND DYNAMICALLY BALANCED

SMALL MODEL FOR SEAKEEPING TESTS

(103)

61, tin ftaemawar I

itit

4,-1/ . 7 '

,:+10 0 1 0 At

,

It

0 d' q) a

t, 0. .,_4,,,,

eal *'

7,

3 to;., 9.

e

,400I

*.;

*:)

1 o o

Co

- -LAW-dik.5a:g.2:'7a. RECORDING APPARATUS FOR MODEL MOTIONS

(104)

FIG. 7-5

MB- 251

(105)

26 FT. 4 FORWARD TANK 6 FT 1 I 1 39 FT. FRAME 41 FT. FIG..7-6 FRAME

GEOMETRY OF A PARTICULAR ANTI-ROLL TANK PROPOSAL

MB-251

FRAME

(106)

FIG.

MB -251

(107)

'

4

(108)

0

w 2.4 a. Lii IL 2.0 cr

z i.6

cr w < 4 Z 0 c7 LL .4 0.8 cr w u-2 inZ IX W 04 I- I- 1G I- Z 02 MO CALE X=5 DEL S 4 6 8 . 10 12 EXCITATION PERIOD SECONDS

ANTIROLL TANK CHARACTERISTICS

01 I '

ID

14 16 18

(109)

2.

FIG. 7-9-2

MB-25I

SCALE 1/64

ANTIROLL TANK CHARACTERISTICS

WEIRS I AND NOZZLES REMOVED 1 0 o cl w a. w C-,

z

a

z

0 cn 41111I 4.1 cc _1 _I o iz a. E U) TANK WEIR 25 10 15 20

(110)

FLUME STABILIZING TANK

IN

(111)

MODEL ROLLING IN WAVES

SHOWING

RECORDER

CONNECTIONS

(112)

-FIG. 7I2

MB 251 14 12 2 SHIP CONDITION A TONS GM 3.03 FT. NO BILGE KEELS WITH BILGE KEELS 0.7

08

09

1.0 II 12

NONDIMENSIONAL FREQUENCY cctin

ROLLING RESPONSE CURVES SHOWING EFFECT OF BILGE KEELS NOTATION

ROLL ANGLE ( AMPL ITUDE )

a :MAXIMUM SURFACE WAVE SLOPE

w WAVE FREQUENCY

DAMPED NATURAL FREQUENCY

OF SHIP

(113)

SHIP CONDITION NOTATION

TONS

GM = 3.03 FT.

k 16.67 FT. IN AIR

TANKS INOPERATIVE

ROLL ANGLE .( AMPLITUDE)

a MAXIMUM SURFACE- WAVE SLOPE

WAVE FREQUENCY

DAMPED NATURAL FREQUENCY

OF SHIP =0.512 RAD/SEC.

WEIRS REMOVED

WEIR ° TANKS

0.7 0.8 0.9 1.0 1.1 1.2 1.3 14 1.5

NONDIMENSIONAL

FREQUENCY-ROLLING RESPONSE CURVES SHOWING -THE EFFECT

OF STABILIZING TANKS

FIG.

(114)

FIG. 7-I52

MB- 251:

: 0

I

hi\

SHIP CONDITION TONS GM: 3.03 FT k:16.67 FT IN AIR TANKS INOPERATIVE NOTATION

ROLL ANGLE (AMPLITUDE)

MAXIMUM SURFACE WAVE SLOPE

(4) r. WAVE FREQUENCY

W: NATURAL FREQUENCY

OF SHIP 0.526 RAD./SEC.

"WEIR" TANKS

07 0 8-

09

1.0

II

1.2 1.3 1.4 1.5

NON --DIMENSIONAL FREQUENCY co

ROLLING RESPONSE CURVES SHOWING THE ADDITIVE

(115)

SHIP CONDITION

FIG. 7-14-1

MB-25I

NOTATION:

9S ROLL ANGLE ( AMPLITUDE)

G : MAXIMUM SURFACE WAVE SLOPE WAVE FREQUENCY

DAMPED NATURAL FREQUENCY OF SHIP

ROLLING RESPONSE CURVES SHOWING THE NEGLIGIBLE EFFECT OF BILGE KEELS IN A PARTICULAR CASE

14 12

-sic

10 re 0 u_ 8 0 i= 6 2 1 0 CC 4 2 TONS GM 5.91 FT. NO BILGE KEELS ITH BI LGE KEELS 0.7

08

09

10

II

1.2 1.3 1.4 NON-DIMENSIONAL FREQUENCY wn

(116)

-0-3.0 1.5 ID 0o

X:64

12 14 16 2 4 6 8 10

MEAN ROLL AMPLITUDE 1/2 (n4" On+ ),

DEG.

(117)

14 12 - SHIP CONDITION: A GM =5.91 FT.

MEM

WITHOUT TANKS WITH TANKS NOTATION:

-ROLL ANGLE (AMPLITUDE) a =MAXIMUM SURFACE WAVE SLOPE

:WAVE FREQUENCY

= DAMPED NATURAL FREQUENCY OF SHIP

FIG. 7-14-3 MB- 251

0.7 0.8 Q9 10 1.1 1.2 1.3 1.4

NON DIMENSIONAL FREOUENCY(ifn'

.TANKS411E EFFECTIVE' IN A .I6ARTiCULAR CASE WHERE BILGE KEELS WERE NOT

(118)

MB -251 .

NOTE- NATURAL DAMPED PERIOD OF VESSEL

TAKEN AS 9 SEC.

ROLLING SPECTRA, ETC. FOR A STATE 6 SEA

VESSEL BROADSIDE ON TO STATE 6 SEA

CORRESPONDING TO 24 KN. WIND SPEED

13

II

5 3

(119)

10% between 10% 10 % 10 % II 10 % 10 % 10% 10 °/o SI 10% 10 % greater than dEa 518 - 2g2

d0/ u/6 e usew2 (Neumann) Ft. and Sec. Units

dEa _ 477'2 slEa_

dui -L VI da)

clEA, dEcr

dw. dw

Root Mean Square Roll

=,\/./

CIEj

o)

dcv

0

STATiSTICAL ROLLING AND WAVEHEIGHT PROBABILITIES (NARROW SPECTRUM)

ck° H(Ft.) Most frequent .705 R.M.S. 4.1 6.2 Average .885 R. M.S. 5.1 7.8 Average of 1/3 higest 1.415 R.M.S. 8.2 12.4 Average of 1/10 higest 1.80 R.M.S. 10.4 15.8 Average of 1/100 higest 2.36 R.M.S 13.7 20.7

Highest expected for 100 waves 2.28 R.M.S 13.2 20.0

Highest expected for 1000 waves 2.73 R.M.S. 15.8 23.9

ck° H( Ft.) O a _32 R.M.S. 0 0- 2.8 .32 8 .46 R.M.S. 1.9 -2.7 2.8 - 4.0 .46 a .60 R. M.S. 2.7 -3.5 4.0 - 5.3 .60 a .71 R.M.S. 3.5-4.1 5.3- 6.2 .71 a .83 R.M.S 4.1-4.8 62 - 7.3 .83 13 .96 R.M.S 4.8-5.6 7.3- 8.4 .96 a 1.10 R.M.S 5.6-6.4 8-4- 9.6 1.10 81 1.27 R.M.S 6.4-7.4 9.6- 11.1 1.27 8 1.52 R.M.S 7.4-8.8 11.1 - 13.3 1.52 R.M.S 8.8 13.3

SOME STATISTICAL RESULTS FROM THE SPECTRAL DIAGRAM

FOR A PARTICULAR VESSEL IN A STATE 6 SEA

FIG. 7.152

MB 251

(120)
(121)

FULL SCALE- PITOT RAKE ASSEMBLY AT

CONDENSER INLET

FIG. 8:-2-t

(122)

FULL SCALE PITOT RAKE ASSEMBLY

AT

(123)
(124)

MO=

ALI

CONDENSER

6 STATICS

MAIN: CIRCULATING. PUMP

7 SINGLE TUBES

( WATER )

;

1

0

13 DOUBLE TUBES ( TETRABROMOETHANE )

:13 PITOTS

VENT

VALVE

OVERBOARD DISCHARGE

DIAGRAM

SHOWING MANOMETER INSTALLATIONS FITTED ON VESSEL

.14 l-1

0.0 0 DD 0

12 DOUBLE tuaEs (MERCURY)

ALL CONNECTIONS TO OUTER TUBES

VENT VALVE IL 0 El - - - 10 OF 1 1 1

)4' /1/44ti.

. /25, .OTS - 5 STATICS

Alkhommall...._

DOUBLE TUBES 10 DOUBLE TUBES (TETRABROMOETHANE SCOOP

(125)

RUN I SHIP SPEED SYSTEM FLOW KNOTS G. PM. RUN 2

SHIP SPEED KNOTS

SYSTEM FLOW G. P M.

SOME VELOCITY DISTRIBUTIONS IN THE INLET PIPING SYSTEM

CONTOURS OF Vig ON CROSS SECTION OF CIRCULATING PIPE VIEWED FROM PUMP SIDE OF SCOOP

RUN 3 RUN 25

SHIP SPEED ,KNOTS SHIP SPEED KNOTS

(126)

HIGH POWER STROBOSCOPE & FLASH EQUIPMENT

(127)

-C -:1 ..,

.

tE.::-.,-^4', = --., -4,17Q 0114, IV4P14#4

4

4, ANALOGUE COMPUTER WITH DIGITAL CONVERTER DIGITAL COMPUTER IN BACKGROUND 7-11111111

-r

_ W

---,. "g4 r . 4e ...powwow.

(128)

CONTROL PANEL FOR MODEL MANOEUVRING SIMULATION a a" a a v,

(129)

e 1f .'"' tyruifiro -0j11110RIO mmt If 7 FIG. 9-'3

MB-251

Cytaty

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