Seminar on Circulating Water Channel, Experimental Technique and Utilization of Circulating Water Channel, Circulating Water Channel Group of Japan, December 1985

(1)

SEMINAR ON CIRCULATING WATER CHANNEL

Experimental Technique and Utilization

of Circulating Water Channel

December, 1985

Circulating Water Channel Group

of Japan

*'"

(2)

(3)

SEMINAR ON CIRCULATING WATER CHANNEL

Experimental Technique and Utilization of Circulating Water Channel

(December 10 and 11, 1985)

Organizer, Sponsor

The Circulating Water Channel Group of Japan

ril5ticittIVA4

Supporting Societies

The Society of Naval Architects of Japan

Japan Ship Performance Committee

Japan Marine Dynamics Research Committee

The Japanese Society of Scientific Fisheries

The Flow Visualization Society of Japan

The Japan Society of Fluid Mechanics

(4)

Experimental Technique and Utilization of Circulating Water Channel

The Japanese Text was published for the Seminar on Circulating Water Channel in

December, 1985 by Tetsuo Takahei. Edited by Tetsuo Tagori. Translated into English

in September, 1986 and printed in Sep., 1987.

Program Committee of Seminar on Circulating Water Channel

Tetsuo Tagori

Taketoshi Okuno

Yukio Takei

Masaaki Namimatsu

Osamu Kishimoto

Michihito Ogura

University of Tokyo (Chairman)

University of Osaka Prefecture

Ship Research Institute (Secretary)

Ishikawajima-Harima Heavy Industries Co. Ltd.

Mitsui Engineering and Shipbuilding Co. Ltd.

West Japan Fluid Engineering Laboratory Co. Ltd.

Office of the Circulating Water Channel Group of Japan

c/o Tetsuo Tagori

Department of Marine Engineering

Faculty of Engineering

University of Tokyo

Hongo 7-3-1, Bunkyo-ku, Tokyo 113

Japan

Liaison Office of Seminar

West Japan Fluid Engineering Laboratory Co. Ltd.

Aza-Kojirna 339-30, Kuroishimen, Kosasa-cho, Kitamatsuura-gun, Nagasaki-ken, 857-04,

Japan

Printery

Toseisha Co. Ltd.

(5)

Preface

The Circulating Water Channel Group of Japan was established in November, 1966,

to exchange the research result and know-how, and to investigate jointly on the design,

research and development, maintenance, management, and utilization of the circulating

water channel.

For example,

the

research

and development on instruments,

experimental methods and expansion of application fields are included also.

Since

then, the regular meetings were held quarterly to present and discuss papers including

the prompt report of research on the above-mentioned themes, and the 77th meeting

was held in November, 1985. Members from 38 organizations of many fields attended

at these meetings, presented and discussed actively results of the researches and

developments on the naval architecture, ocean engineering, fishery, mechanical and

aeronautical engineering, sports, and health keeping. Moreover, many joint

investiga-tions were carried out on the performance and use of the circulating water channel.

As a result, data obtained by the experiment in the circulating water channel become

to put to practical use, by the remarkable improvement of performance and the

progress of experimental technique. And the utilization field spreads widely.

At greeting the 20th anniversary of the Circulating Water Channel Group of Japan,

the seminar was planned to make a comprehensive compilation of research results of

members and to develop the utilization of circulating water channel.

It is believed that the contents of this seminar will be put to practical use and be

useful to the one carrying out experiments in the circulating water channel.

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CON ETNTS

Page

Preface

Frontispiece

Photographs of Circulating Water Channels and Experiments in Them

Opening Address to the Seminar

by Tetsuo Takahei, Nihon Kagaku Kogyo Co., Ltd

1

On the History and Prospect of Circulating Water Channel

by Tetsuo Takahei, Nihon Kagaku Kogyo Co., Ltd

3

Characteristics of Circulating Water Channel

by Michihito Ogura, West Japan Fluid Engineering Laboratory Co., Ltd

13

Measurement of Hydrodynamic Force and Pressure

39

4.1

Measurement of Hydrodynamic Forces

by Yukichi Nagashima and Kunihiko Shirota, Tsu Laboratories,

Nippon Kokan K.K.

39

4.2 Measurement of Pressure

by Nobuo Nagamatsu, Kawasaki Heavy Industries, Ltd

46 On the Velocimeters

55

5.1

Flow Measurement by Hot-film Probes

by Takio Hotta, Faculty of Engineering, Hiroshima University

55

5.2 Laser Doppler Velocimeter

by Yukio Talcei, Ship Research Institute

65

5.3

On the Use of Pitot Tubes and Other Velocimeter in CWC

by Talcetoshi Okuno, University of Osaka Prefecture

73

Flow Visualization Technique in Circulating Water Channel

by Tetsuo Tagori, Faculty of Engineering, University of Tokyo

81

Application of CWC for Experimental Researches in Shipbuilding

by Masahiro Tamashima, Hiroshi Isshiki, Masaaki Namimatsu

*

West Japan Fluid Engineering Laboratory Co., Ltd

**

Hitachi Zosen Corporation

***

Ishikawajima-Harima Heavy Industries Co., Ltd

95 Utilization of C.W.C. for Ocean Development

by Osamu Kishimoto, Mitsui Engineering & Shipbuilding Co., Ltd.

125

Applications of CWC for Fisheries

133

9.1

On the Experiments for Fisheries

by Kiyoteru Kimoto, Hakodate Seimo Sengu Co., Ltd.

133

9.2 Measurements of Swimming Resistance of Aquatics

by Yoshikazu Narasako, Faculty of Fisheries, Kagoshima University

147

Use of Circulating Water Channel in the Field of Sports and

Health Keeping

by Tetsuo Tagori, Faculty of Engineering, University of Tokyo

157

Applications of CWC for Experimental Researches in Aeronautical and

Mechanical Engineering

(7)

Photographs of Circulating Water Channels

(8)

Fr. 1 Horizontal Type Circulating Water Channel (1965)

Fr. 2

Horizontal Type Circulat-ing Water Channel with

Wave Generator and

Blower (1978)

Fr. 3

Resistance

Test of Ship

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Fr. 4 1/20 Model of Vertical Type Circulating Water Channel (1978)

Fr. 6 Rotor Type Surface Flow Accelerator

ii Fr. 5 Main Impeller Fr. 7 2 Impeller Vertical Type Circulating Water Channel (1983)

(10)

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Fr. 10

Flow around Bow Bottom of Ship Model (Depth Tuft Method)

Fr. 12

Surface Flow of Ellipsoid (Oil Film Method)

iv

Fr. 11

Flow around Bow of Ship Model

(White Lead-Ammonium Sulfide Method)

(12)

Fr. 13 Flow around 2 Dimensional Model

(Tuft Grid Method)

Fr. 16

Collision Model Test of Driftwood on

Propeller Protector for High Speed Boat

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Fr. 14 Wake of Ship Model (Tuft Grid Method)

Fr. 15 Flow around Bridge and Funnel of Ship Model

(13)

Fr. 17

Necklace Vortex around Bow of Ship Model (Hydrogen Bubble Method)

V Fr. 18

Flow around Stern of Unstable Ship Model at Propulsion Test

(Dye Injection Method)

Fr. 19

Wake of Unstable Ship Model at Propulsion Test

(Tuft Grid Method)

(14)

Fr. 20 Tip Vortex of Model Propeller (Dye Injection Method)

Fr. 22 Surface Flow of Model

Propeller (Oil Film Method)

Fr. 21 Race of Model Propeller (Air Bubble Injection Method)

Fr. 23 Flow around Hydrofoil Shaped Propeller Blade

(Air Bubble Injection Method)

(15)

Fr. 25 Flow of Gilbert Fish Preserve (Dye Injection Method)

Fr. 24 Spread Test of Fishing Net Model

viii

Fr. 26 Flow around Caisson (Upper: Paint

(16)

Fr. 27 Surface Temperature and Streak of Turbulent Boundary Layer of Flat Plate (Temperature Sensible Film Method and Hydrogen Bubble Method)

.1110igatragial

Fr. 28

Experiment of Flat

Plate Model for Film Cooling of Turbine

Blade (Dye Method)

Fr. 30 Wake of Delta

Wing (Tuft Grid

Method)

Fr. 29 Flow around STOL Model (White Lead- Ammonium Sulfide Method)

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(17)

Er. 32

Flow around Human Model (Surface Tuft Method)

x

Fr. 31

Wake of Fast-Back Type Automobile Model

(Tuft Grid Method)

Er. 33

Surface Flow around Human Model (Oil Film Method)

(18)

Fr. 35 Flow around Ski Jumper Model(Air Bubble Suspension Method)

xi

Fr. 34

Flow around Human Body at Swimming (Surface Tuft Method) a: Crawl Stroke b,c: Breast Stroke

Fr. 36

Wake of Ski Jumper Model

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C.W.C. Seminar 1985

1. OPENING ADDRESS TO THE SEMINAR

by Tetsuo Takahei*

In the last chapter 'Does the story continue?' of his book 'The Face and the Back',

which has recently attracted public notice, Dr. T. Doi, a psychiatrist, says 'Men do not

like to predict the future when they have Hope. It is the exact meaning of 'hope' that

they expect something good though they don't know actually what it will be like.

I had indeed the some feeling when the circulating water channel group Japan

(CCG) was opend 19 years ago, in November 1966, after consultation with Prof.

Tagori, believing that anyhow we could get something interesting about the circulating

water channel in this small meeting. By now, August 1985, we have already had 76

meetings, regularly 4 times a year. Our members are not only from universities,

technical institutes, technical high schools and some institutes for the naval

architec-ture but also from those for the fishery science and mechanical engineering, which has

amounted to 38 organizations. Each of them possesses characteristic facilities of

circulating water channel and uses them for the education and daily works.

The purpose of CCG is to elevate the performance of circulating water channel, to

enlarge its use and to improve the experimental techniques for the flow visualizations

and model tests, in exchanging "io-ho' (information) among the researchers of this

field.

'Jo-ho' is said to have been created by Ogai Mori, a famous novelist, as a translated

term for 'Information'. As this term lo-ho' consists of two parts, 'Jo'

(human feeling)

and 'Ho' (data or fact), the significance of our CCG is not merely

_{to get the materials}

distribution in every meeting but also to promote friendly relations

_{among us, which}

results in making the activity of this group go further.

I would like to record my deepest gratitude to the

_{careful management of the}

program committee and the close cooperation and support made by

every member

since the plan of Seminar was first proposed three

_{years ago.}

Kyoshi Takahama, a 'haiku'

poet, sang;

Kozo Kotoshi tsuranuku bou no gotoki mono

(Last year seems, like a stick, to have been stuck into this year)

The New Year will soon come. I wish CCG of Japan grow much more than ever,

making this Seminar a stepping stone to the future.

* President of the Circulating Water Channel Group of Japan

Nihon Kagaku Kogyo Co., Ltd.

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-C.W.C. Seminar 1985

2. ON THE HISTORY AND PROSPECT OF

CIRCULATING WATER CHANNELS

by Tetsuo Takahei*

2.1 Introduction

The title is given as "The History and Prospect of Circulating Water Channels",

but it is difficult to follow the complete history of Circulating Water Channels

(CWCs) and their design, development and construction. Here the author describes

the progress of their development, mainly during the twentieth century, based on

the relevant data available on the world wide facilities for testing ship models

[1]. For the future, a few problems of the present CWCs are pointed out in

expectation of further progress.

*formerly Nihon Kagaku Kogyo Co., Ltd.

2.2 Development of CWCs bofore The CWC Group of Japan was formed

Five centuries ago, Leonardo da Vinci (1452-1519), a great artist and

scientist, sketched the vortex flow behind an obstacle, using his acute

observation, as shown in Fig. 1 [2]. The Figure suggests that he was aware that

aspects of the vortex flows are influenced by the shape and size of the obstacles and also the flow velocity. His work was the biginning of scientific research into

variations of flow fields. For this purpose it became necessary to design water

channels where the flow velocity could be varied. Therefore, simple water channels were biult as part of this research.

In the 1850-s, following the Industrial Revolution in England during eighteenth century, large iron ships driven by reciprocating steam engines were built instead

of the traditional wooden sailing ships used until then. With this development,

the improvement of hull design and the prediction of both the ship speed and the

required engine power became urgent problems. At the end of eighteenth century,

towing water channels driven by a gravitational method for testing ship models

were constructed in Europe. In Torquay, England in 1872, a water channel facility

was completed on the basis of William Froude-s Similarity Law defining the

relationship between models and full scale ships. In this facility, the apparatus

for towing the ship model was driven on a constant speed by a steam engine. At

that time William Froude was 62 years old. After he had proved the usefulness of

water channel tests, many water channels were built in European countries.

Later on, the invention and wide use of electric motors at the end of 19th

century led to the present style of water channels, in which the apparatus for

towing the models is self-moving, having the motor on board. For example, the

towing water tank No. 1 of NMI ( National Maritime Institute; the old NPL,

National Physical Laboratories), Feltham, England, was built at 1910 and was 9.1m

wide, 3.7m deep, and 152m long. It is still working, although it now has a

thyristor-control system giving 104kW power and a maximum speed of 4 m/s.

In England in 1910, following the

towing tanks, an enclosed-circulating

reduced-pressure type water tunnel

-appeared, we call this a "cavitation

-tank" or "cavitation tunnel", as it was

built by Parsons to investigate therl"

cavitation phenomena occuring around

-marine propeller. After that, cavitationr.

tanks were constructed from the latter

*4-i

half of 1920s- to 1930 in various

countries around the world. -

-In the cavitation tank, the

observa-tion of cavities, occuring on propeller

blades, is made using a light

synchro-nized with the revolution of the

propeller. The observation of flows

around a ship model is not easy in a _{_}

towing tank, because of the problem of

-the observing apparatus , the contamina-

,-tion of the water, the limited observing

time and space, and so on. For this

Fig. 1 Vortices sketched by Leonardo

purpose, the circulating water channel

(21)

Versuchsanstalt ftir Wasserbau und Schiffbau Berlin, constructed a vertical type

CWC, with a total length of 16.3m, a height of 6.58m and a working section of

6.99m long.

On the other hand, firstly in U.S.A., in 1899, a towing tank facility was built

in a naval building in Washington D. C., under the supervision of David W. Taylor.

They had a towing apparatus driven by four motors and controlled by the

Ward-Leonard system. After that, in 1929, a wind tunnel and a variable pressure type

cavitation water tunnel with the measuring section having a diameter 12 inches

(305 mm) were built successively. To expand the facilities for testing ship

models, further, in 1936 Harold E. Saunders started the construction of a very large-scale test facility at Bethesda, on the North shore of the Potomac River, 20

km N.W. of Washington D. C. This facility was then expanded into the current

DT4SROC (David W. Taylor Naval Ship Research and Development Center). The main

towing tank was completed at 1939, and then finally in 1944, a large-scale

vertical type CWC was constructed. As shown in the schematic diagram of the CWC

in Fig. 2 [4], the CWC had a total length of 44.7m and the working section was

18.3m long, 6.7m wide and a maximum depth of 2.7m. This working section had a

gradual connection and reduction from the enlargement section for calming the

water stream. An adjustable long lip was set at the inlet of the working section to smooth the free water surface. The power was supplied to the water flow, giving

a maximum velocity of 5.1m/s in the working section, using a 3.8m diameter

impeller with variable pitch driven by two electric motors, each having a

capacity of 932 kW. The design of this water channel was fairly good even if seen

from the viewpoint of current technology, except for the problem of excess air

entrainment at velocities larger than 2m/s, because no consideration was taken for

the downstream flow of the working section. It is interesting that Saunders

emphasized the visualization of flows around hulls and their appendages as the

primary purpose of this CWC. In the CWC, actually, filters were prepared to keep

the used water clean, as required for flow visualization.

Concerning the naval architecture of Japan, probably the first CWC was built at

the old Naval Technical Research Laboratory, Meguro, Tokyo, in 1942, although it

is no longer in existence [3]. The Nagasaki Experimental Tank, Mitsubishi Heavy

Industries, Ltd., in 1950 was a wooden CWC with a working section 0.5m x 0.5m and a maximum velocity of 0.8 m/s. It was used to examine hull forms around 1950. Then

in 1953, a horizontal type steel CWC was constructed. This steel CWC had a total

length of 7.2m and a width of 3m, with the working section 4m long, 1.2m wide, and

0.8m deep, it operated at a maximum flow velocity of lm/s. This CWC was moved to

the University of Tokyo in May, 1964.

The Tokyo Fisheries University built a horizontal type CWC in 1952 for research and development of fishing equipment such as fishing nets. The feature of this CWC was that it had a fixed shape over the whole length of the channel with a width of

0.8m and a depth of 0.5m, and it operated at a flow speed of 0.1 to 0.7 m/s

through two impellers set in parallel, driven by a 2.25kW power electric motor.

A typical old CWC was built at 1955 at Hiroshima University, and it is still in

use. For the old CWC, it is interesting to note that at first, Professor T.

Aoyama, who moved to Hiroshima University from Nagasaki Lab., Mitsubishi Heavy Industries, Ltd., ordered the construction of the CWC (1.2m wide, 0.8m deep, and

Guide Vanes Enlargement Section

2 ea /750 HP Impeller Motors Free Water Surface Begins Here

Adjustable Lip Viewing Windows Water Lev.

2.7 m ft)

= =

I Impeller

Diffuser

44.7 in 1146.8 ft/

1 1 II.

Appro. Length of water circuit measured around the cerrterlines 99 nt 4325 ftl

Fig. 2 A vertical type CWC in David Taylor Naval Ship Research

and Development Center (USA).

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-..

-PLAN_

FRONT V I EW

Fig. 3 A horizontal type CWC at the National Maritime Intstitute (U.K.).

with a maximum velocity of 1 _{m/s) from Mitsubishi Heavy Industries, Ltd., and then}

used it for various tests concerning in naval architecture at the university. The

CWC was widely used for flow visualization and for measurement of various

properties such as the surface pressure and the local skin friction of ship

models, the turbulence in boundary layers and entrainment flows, and so on, for 27

years from 1955 to 1982. Accompanying the movement of the Faculty of Engineering,

Hiroshima University, the CWC was also moved to Kanazawa Institute of Technology,

and is still used after the surface flow acceleration equipment was added. In

addition, in 1955, a similar type CWC was constructed for research into marine

insruments in the Fishingboat Laboratory, the Fisheries Agency (currently,

Department of Fisheries Engineering, Institute of Marine Industry Research).

Both CWCs built in the Departments of Fisheries, Kagoshima University 1955) and

Hokkaido University (1956), are spectacle-shaped, horizontal types, in which the

water is _{circulated by using two feathering type paddle wheels set} _outside _the

loop. The one at Hokkaido University was improved in 1974 with the power increased

to 22 kW, _{a maximum velocity of 2m/s, and a longer channel. At first the power was}

15kW and the velocity range 0.1 to 1.0 m/s. Furthermore, the CWC had _{a towing cart}

running _{distance of 10m with the working section and is used for the} _observation

of flows around artificial fish reefs in the vicinity of fish farming facilities,

the fluid force measurement, the analysis of the fluid force and motion acting on

fishing equipment and fishing nets, the measurement of fish's path of movement, and so on.

Meanwhile, _{in England, progress was made with a plan for the construction of} _a

new type CWC at the old NPL, Feltham. At the start, the planning was commissioned

from the University of Cambridge by The Society of Ship Research, Great Britain,

and later it was put in practice by NPL. Based on results of model tests beginning

in 1958, the construction of the CWC was started in 1961 and finished at the end

of 1965 [5]. This CWC is an open-channel type, 120m in the total length, having a

test section 18m long, 3.6m wide and 2.4m deep (the depth is adjustable within 1

m). There, the velocities in the range of 0.3 to 3.0 m/s are controlled by

adjusting the open angle of multiple impeller type sluices which are set

downstream at the end of the test section. The circulating water is returned to

the upstream section, after filling in the reservoir, through an eight variable

pitch blade impeller driven by a 1700 kW motor. Though more power is required than

with _{the enclosed-loop type utilizing the kinetic energy of the water,} _{the water}

flow in the test section has less disturbance on the surface, steady low frequency

waves, less flucuation of water level induced by surging, and less contained air

bubbles. Because, in the test section the water is constructed in the reduction ratio 9:1 from the upstream enlarged settling open channel with the length of 30m.

2.3 _{Construction of CWCs after starting of CWC Group of Japan}

The 11th International Towing Tank Conference (ITTC) was held in October, 1966, Tokyo, in which many researchers concerned with test tanks for hull form and naval

hydrodynamics participated from many countries around the world, and they

-5--- _ _

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actively discussed a comprehensive range of subjects such as testing methods for

hull forms, estimating methods for carrying out test runs, and so on. From the

viewpoint of economics in the shipbuilding industries around 1950, unique hull

forms were adapted for tankers and ore carriers; they were very broad and had a

low ratio of length to width, compared with the conventional hull forms.

Consequently, problems arose concerning the flow field around the hull, related to

the resistance and propulsion performance, the operation and turning performance,

the vibratory force of propellers and cavitation phenomena, etc., and then it was

recognized that subjects concerning with various phenomena such as critical stream

lines and the generation of vortices in boundary layers and separated flows, should be investigated for flows around a model ship, as well as conventional

tests of the hull form. A CWC was constructed to begin investigating these subjects, in Tagori Laboratory, Department of Marine Mechanical Engineering,

University of Tokyo, in the 1966. In November, 1966, in accordance with the lead

by Professor Tagori and the author, The Circulating Water Channel Group of Japan

(CWCGJ) was set up to meet and discuss the use of CWCs for observing flow fields around hulls, because there were technical problems with conventional towing tanks. The CWCGJ has held meetings four times a year, and their 76th meeting was

held in August, 1985. It has 37 members, consistingof or ganizations such as

universities, colleges, laboratories and industrial companies which had CWC

facilities in the past or are planning have them in the future. The CWCGJ aims to

contribute to the development of CWCs and their utilization techniques by exchange

of information and co-operation on various subjects related to CWCs, for example,

the design and construction, the assessment and improvement of performance, the

development, the maintenance and management, the development and improvement of

measuring instruments, experimental procedures, and utilizing actual results.

After the CWCGJ was formed, CWCs were slowly introduced into Japan, and now

more than 40 CWCs have been constructed in various sizes and types, including

those for fishery engineering, for observation of flow fields around mechanical elements, etc.

The CWCGJ has carried out the following co-operative work for the technical improvement of CWCs:

Measurement of pressure profiles around a circular cylinder (1967 to 1969). (for estimating the intrinsic turbulence of CWCs)

Resistance tests using the same ship model (1972 to 1974)[8]. Issued a collection of CWC drawings (1976).

Issued a collection of measuring instruments for CWCs, vol.1 (1979). Issued a collection of CWC drawings (supplement) (1981).

Issued a collection of measuring instruments for CWCs, vol.2 (1931). Further, the following works are in progress or under consideration:

Void fraction ( air bubble fraction).

Surging.

Wave generation techniques.

Measurement of intrinsic turbulence by hot-film anemometry. Stability of CWC's basic performance.

Application of a laser Doppler velocimeter to CWCs. Self-propulsion tests using the same ship model.

These works have clarified both the CWC's characteristics and the procedures

dealing with a succession of pertinent problems. In the CWCs belonging to the

CWCGJ, the range of velocities is almost up to 2 m/s and usually around 1 m/s in

spite of the difference in sizes. Problems pointed out in the CWC's performances

when the CWCGJ was formed were as follows [9]:

(1) Slowly swirling stream and inconsistency of sectional velocity profiles,

particularly the velocity damping closer to the water surface for the flow in the

working section [10].

(2) Wave motions occuring on the water surface, which are classified into the

following three categories:

Steady waves: wave existing at the water surface, in which the length and

height change with the velocity, but the position of the peak and valley is fixed relative to the tank wall [11].

Surging: fluctuation of the average water level, occasionaly with a very

low frequency beat motion superimposed.

Inclined water level: the average water level drops in the downstream flow

due to the friction loss along the tank wall, which is inclined nearly in

proportion to the square of the velocity, actually about 5x10-4 at a

velocity of 1 m/s.

(3) Blockage effect --- when the sectional area of a model is fairly large in

comparison with that of the working section, measured data are influenced by the

blockage effect, because of the accelerated flow near by the model's position.

Regarding the hull form, the blockage effect is negligible within a ratio of the

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-6--channel width to the hull length less than or equal to 1.5; the value of 4v/v is

assessed less than 0.5% at the position of the hull, where v is the velocity of

the main stream and Av the increased velocity component. However, when using the

water channel where the ratio of the model's sectional area to that of the channel

is significant (several %), the proper velocity correction relative to the model

is required.

Reynolds number effect --- in general, CWCs have turbulence intensities of 2%

or more and a large turbulence scale of about 0.1 m. While towing tanks have weak

turbulence intensities of 0.1%. Therefore, the relative Reynolds numbers for CWC

tests are larger than that for towing tank tests.

Contained air bubbles --- air bubbles are mixed with the water flow, because

of the entrainment of air at the downstream end of the working section of CWCs.

Even if air mixtures in the water are reduced by utilizing the buoyancy effect in

slowdown of the flows, very small bubbles less than 1 mm in the diameter cannot be eliminated and will circulate with the water. Consequently, air bubbles adhered to

the surface of a model will influence the measurements by a hot-film anemometer or

a laser-Doppler velocimeter. This must be taken into consideration beyond a flow

velocity of 1 m/s.

For the above problems in the performance of CWCs, in particular, for problems

(1) and (5), remarkable improvements have been made by better CWC designs. At the

same time, CWCs have often been used to improve hull forms and their innovative use with practical examples has been proposed [12].

Forty or more CWCs have been built since the formation of the CWCGJ in Japan,

as mentioned already, and their use has increased annually become. In 1970, a big

vertical type CWC was constructed at the Research Institute, Mitsui Engineering

and Shipbuilding Co., Ltd., the first in Japan [13]. Subsquently, various

improvements have been made to the CWC, such as the automatic operation and

control systems, the data acquisition and processing systems, etc., by employing a

computer, so that both effective testing procedures and accurate measurements could be achieved.

Figure 4 shows a schematic of the biggest vertical type CWC in Japan. The CWC

was first constructed in the Tsurumi Laboratory, Nippon Kokan K.K.[14], in 1974

and moved to the Ship and Offshore Performance Research Department, Tsu

Laboratory, in 1977. This has a total length of 26.6m, a height of 7.2m, a nozzle

contraction ratio of 3.43, and a working section 9m long, 2.5m wide and 1.355m

deep. It operates within a velocity range of 0.2 to 2.5 m/s through a fixed four

blade impeller with a 110kW motor. In the CWC, model ships with a maximum length

of 3m can be used. To avoid the velocity damping closed to the water surface in

the working section, devices are set up to accelerate the surface flow at the

outlet of the nozzle corresponding to the upstream part of the working section. In

November, 1984, a computer system was adapted to control the operation of the CWC.

- 26600 FL ±0 3650 300 3700 1000 23330

-

7

-FL +6175 AWAII700

®

MEM 2230120041875 2025 700 (numerals. in mm)

(1) Observation section (2) 1st corner (3) 2nd corner

Diffuser (enlarge angle, 7'40 in horiz., 4"in vert.)

3rd corner (6) Settling grid (7) 4th corner (3) Settling grid

(9) Controller (10) Metal mesh (11) Panched metal

(12) Observation window (toughened glass, lOmmx2) (12) Pump

Fig. 4 A vertical type CWC at Tsu Research Lab., Nippon Kokan K. K.

(25)

Surface flow

accelerating apparatus

Honey comb Observation window

Flow reducing 7],apparatus -

in

IIIIIIII

11111L.Ala

90kW DC motor 20000

Fig. 5 A vertical type CWC at Hakodate Seimo Sengu Co., Ltd.

A vertical type CWC was built at the Yokohama Research Institute,

Ishikawajima-Harima Heavy Industries, Co., Ltd., in June, 1933, for the main purpose of making

a smooth flow containing few air bubbles. In the CWC, therefore, several new

devices have been used to make uniform velocity profiles by setting the water flow

acceleration equipment at both the surface and the bottom of the nozzle outlet

located in the upstream working section, and to provide an observation window made

of heat-resisting glass inclined 45 degrees at a corner of the observation

section.

The design of CWCs depends on the purpose of the tests. In the CWCs used for

the fisheries tests, a transferable bed moved by belts may be set at the bottom of

the working section to experimentally simulate the towing situation of a fishing

net along the seabed.

Figure 5 shows an example of the CWC, built in Hakodate Seim° Sengu Co.,

Ltd.[15] which has a working section 6m long, 3m wide and 1.2m deep and a total

water volume of about 250tons. It is operated at a maximum velocity of 2m/s. At

the bottom of this CWC, a transferable bed driven by a conveyer belt is provided

to make running at the same speed and in the same direction as the water flow.

As many big tankers are now in use, marine environmental problems such as sea

contamination by oil materials have become serious and urgent subjects. For the

research and development of equipment to investigate these problems, the Institute

of Marine Environmental Technology was constituted in 1978 in Tsukuba, Japan, and

a big CWC was constructed there [16]. This CWC, as shown in Fig. 6, can be used

for various simulation tests on the performance and behavior of oilfences and

oil-recovery equipment, on performance and behavior of ships and marine structures,

and on water surface motion related to wind, waves and tides, etc.

Thus, CWCs have been widely used, not only for general ship testing, but also

for such fields as fishing boats, marine developments, fisheries, aviation,

mechanical engineering, etc. Further, recently the range of uses has been expanded to fields connected with physical education and medical treatment.

2.4 Prospect of Circulating Water Channels

A symposium on the development of hull forms and test tanks was held in

February, 1983 [3], sponsored by the 1st branch of the Test Tank Committee, The Society of Naval Architects of Japan, where techniques for testing propulsive performance in the present towing tank have been frankly discussed.

Propulsive performance tests using a towing tank have been examined and proved

for a century or more since Froude's work and are now precisely standardized. Many

test results obtained by the standardization and accumulated data for the design

of shipbuilding related to their correlation with actual trial runs of ships

enable the prediction of the ship propulsive power at a higher accuracy (within

2%). If we called tests carried out according to these formulated methods

"Engineering tests", few data of "Engineering tests" on conventional hull forms

would be useful for the development of hull forms. It is surprising how many kinds of hull forms are being developed recently for the shipbuilding industries.

For these current hull form developments, testing methods based on practical

physical measurement are required, taking into consideration the hydrodynamic

resistance and propulsion of hull forms under both a flexible conception and a

considerative development plan [17]. Further if the numerical computer simulation

capable of estimating various characteristics of hulls, such as the critical

(26)

-8-13

60.0 80.0 77.0

-9-15.5 (C-C sec ion) LC, 15.5

9-Test section (7) Blowing cart

Returning section (8) Surface contraol cart

Wave-making device (9) Mechanical chamber

Wave-reducing device (10) Cleaning pit

Pump (11) Mono-rail whist

Measuring cart

Fig. 6 A horizontal type CWC at the Marine Environmental Institute of Technology.

streamline, the separation position, the wave-making resistance, the propulsive

performance and so on, could be done before the tank tests, it would promote

development and help to reduce the cost of development.

In a test using a towing tank, the size of the model ship has to be longer

than 7m to preserve the certain correlation between the model and full scale

ships, for the hull form development required by the shipping industries, for

example, on full-form ships like tankers and for energy-conservation after the so

called "oil shock". At the same time, very exact and stabilized measuring

instruments have to be used to ensure the accuracy of their tests. Water used in

the tank also has to be kept clean by filtering, and the water temperature kept

uniform at all depths by water circulation. In addition, we have to take account

of the adhesion of air bubbles to the hull during the spring to the winter with

severe changes of atmosphere temperature in Japan. Because , when the tank water

is saturated with disolved air, changes in temperature will expell air to form

very small bubbles less than several 10 pm in diameter which adhere to the hull

surface coated with paraffin wax. These adhered bubbles increase the hull's resistance. For eliminating air bubbles, therefore, in the Yokohama Research

Institute, Ishikawajima-Harima Heavy Industries, Co., Ltd., the tank ( capacity

10,000m3) was continuously operated for a year using air reducing equipment capable of processing 20m, an hour, and then 100cc a day of dissolved air could be

reduced for the water of one cubic meters,in particular, by decreasing the

saturation ratio in the vicinity of the water surface. (A-A section)

(27)

-10--BOW NECKLACE VORTEX BOW BOTTOM SEPARATION VORTEX

STERN BILGE SEPARATION

VORTEX (PRIMARY)

DITTO (SECONDARY)

STERN HYDRAULIC JUMP VORTEX

PROPELLER VORTEX

Fig. 7 Illustrative figure of the vortices caused by a ship.

As obviously in the above description, the towing tank would be very expensive

both to construct and to operate as typically about 40 days are required from

determinating of the lines of ship forms, to receiving the test results and this

costs about 7 to 10 million yen. On the other hand, in a circulating water channel, the size of the ship models used are 1.5 to 2 m long, so that new

polystyrol hull forms can be used as well as the conventional wooden ones and then

the test expense can be reduced compared with the towing tank test. The direct

estimation of a full scale ship's performance from test results carried out using

small models in CWCs is difficult at present, but if the relationship between

their test results and those using large models in towing tanks would be confirmed

for ,many of kinds of hull forms, it help to reduce the cost of development. Here

we describe typical examples where CWCs were used for hull form development.

Tagori et al. proved by the flow visualization technique that for the obese

full hull form having a very large width compared with the length, flow profiles

at the propeller position of a hull stern made a unique hill-shape and vertical

vortices with the axis in the direction of the length of the hull, occuring in the

same position, would be induced by the three-dimentional separation of flows

around the bilge part of the hull tail. Around the full hull, various vortices may

occur due to the separation flow at positions of both the bow and stern of the

hull, as shown in Fig. 7 [18]. These phenomena have been confirmed by

three-dimensional boundary layer calculation, the investigation for scale effects of

vortices due to boundary layer suction of the ship model, and the flow

visualiza-tion, since the formation of CWCGJ, in 1966. Besides, for the full form, the

self-propulsion test in a towing tank provided the result of an unstabl.e phenomenon

like a loop shape. To anaylze this phenomenon, the use of a CWC helpd very much.

Furthermore, CWCs built in various places have been used for new hull form

develo-pments and for a wide range of tests of hull forms, such as SR159, 1976 to 1973;

6R171, 1977 to 1979; SR174, 1977 to 1979. As an example of the process of hull form

development, we refer to the Australian

Yacht "Australia II", which defeated the

American "Liberty" by the small margin of 21

seconds in the final race of the Americas

Cup Yacht Race, on September 25, 1933.

"Australia II" was designed by Ben Lexcen,

and it had a big horizontal delta-shaped

wing at the end of the keel hung from the

hull bottom and a spherical shaped keel in

the front, just like the bulbous bow diving

in the water, as shown in figure 2.8. For

the design, the test was conducted in

Wageningen Tank, MARIN (Maritime Research

Institute Netherlands). Before the test using a model ship, the hydrodynamic

characteristics of hull design were

investigated by replacing its lines in a

hydrodynamic model. In such numerical

experiments, the changing of shapes is

Fig. 3 Unique keel of "Australia II"

possible by the variation of parameters, an

(Photo. by K. Soehata)

optomum shape is decided, and then it is

(28)

To utilize CWCs for the development of the hull form, it previously required confirmation of the correlation between the small model test in CWCs and the large

model test in a towing tank. It is therefore an important problem for the future

that not only the performance of hardware has to be the improved so as to

eliminate the unstable elements in the CWCs, but also the designing of software

has to be improved to solve the problems of correlation.

Recently there have been very great advances in fluid measuring techniques.

These new techniques has been applied in experiments and the observation with

CWCs, and are also useful for studying unsolved problems, as pointed out

previously. As a typical example, flows around the propeller will be studied.

ro

improve the propulsive performance of a ship, it is necessary for the correlation

between the hull, the propeller and the helm to be clarified for the wake flow

around the stern. To measure the entrainment flow, a Pitot tube and a 5-holed Pitot tube have previously been used, after removing both the propeller and the

helm from the hull. The design of a propeller is made, based on measured profiles

of the wake flow, the design of a propeller is made. Effects of the propeller and

the helm on wake flow distribution are estimated merely by contrast with the

effective values based on propulsive coefficients obtained from the result of

self-propulsion tests. By using a laser Doppler velocimeter (LDV), the wake when

using the propeller can be measured three-dimensionally and then the above

mentioned mutual interference can be cancelled. Further, the use of an LDV is

expected to have much merit in measuring the flow angle against the helm in the

turning motion and the velocity components required for the exact estimation of the driving force on the operating ship's helm. For three-dimensional measurement,

a few LDV systems with different optical system are coming onto the market, from

Dantec Electronik Co., Ltd. (Denmark) [20], TSI Inc. (USA) [21] and Kanomax Inc.

(Japan), and some data measured by these have been presented.

Although CWCs recently built in Japan are operated at the velocity of 2.5m/s at

the most, CWCs with a maximum velocity of more than 6m/s are desirable for

expanding the range of uses. However, in the open-channel type CWC with a free

water surface, the operation at higher velocity induces increased air bubbles in

the water, mainly produced in the downstream working section, and these interfere

with the observation. To eliminate mixed air bubbles, the floating method at a

sufficiently reduced flow velocity has been used so far, but this method has the

the shortcoming that the power required for driving the tank becomes larger.

Recently, a new method is being attemted, this is to eliminate air bubbles

concentrated in the center part of revolutional flow by using a cyclone in the

bottom flow of the working section.

For flow visualization, it is desirable that little turbulence exists in the

flow. In CWCs associated with the CWCGJ, the turbulence intensities range from 1

to 2 % and the turbulence scales are around 0.1m. Further, for the treatment of

problems of the transition and separation phenomena in the boundary layer around a

body, a weaker turbulence is required, while flows having the turbulenc intensity

less than 0.11 are often encountered in wind tunnels. In Europe and America, there

are a few examples of vertical type water channels which were constructed only for

flow visualization. They have a head tank on the top, a large reduction ratio of 5

or 6, and a two-dimensional observation section. Even for the CWC, if a larger

reduction ratio is used with many fine mesh nets to calm the flow, the turbulence

of the flow can be decreased to an intensity of 0.2% [22]. Studies of these

problems will be made in the future.

The usefulness of CWCs has been recognized not only in Japan but also in the

other Oriental countries having an interchange of technology with Japan.

Horizontal type CWCs were constructed at 1932 in Chung chang Institute of

Technology, Taiwan, and also at 1983, in Shanghai Ship Transportation Laboratory,

Ministry of Traffic, China. At 1984, a new CWC was built as well as a towing tank

by Hyundai Heavy Industries, Co., Ltd., Korea. In future the CWCGJ intends to

(29)

References

Catalogue of Facilities, 15th International Towing Tank Conference (1931).

Chapter on Mechanics of Water and Stone, Unknown topics on Leonardo,

Iwanami-Books, p.192 (1975).

Yokoo, K.: The Start and Development of Towing Tank, Symposium on Development of Ship Hull Forms and Test Tanks, 1st Branch, Test Tank Commitee, The Society

of Naval Architects of Japan, Feb. (1933).

Saunders, H.E. et al: The Circulating Water Channel of the David W. Taylor

Model Basin, SNAME, Vol.52 (1944).

Steele, B. N. et al: Design and Construction of the NFL Circulating Water

Channel, Symposium on Experiment Facilities for Ship Research in Great Britain

(1967).

Takahei, T.: Circulating Water Channels in Japan, Jour. of The Society of Naval Architects of Japan, No.461 (1967).

Takahei, T.: Applications of Circulating Water Channels, Jour. of The Society of Naval Architects of Japan, No.503 (1971).

Takahei, T. et al: Resistance Test in a Circulating Water Channel, Jour. of Kansai Society of Naval Architects, Japan, No.159 (1975).

Tagori, T.: Current Circulating Water Channels and their Problems,

Turbo-machinery, Vol. 1, No. 1 (1976).

Ogura, M. et al: On a Surface Flow Accelerating Apparatus for a Circulating

Water Channel, Jour. of Seibu Society of Naval Architects, Japan, No.43 (1974).

Himeno, R. et al: On the Steady Wave in a Circulating Water Channel, Jour. of Kansai Society of Naval Architects, Japan, No.155 (1974).

Takahei, T. & Ogura, M.: Applications of Circulating Water Channel, Symposium

on Development of Ship Hull Forms and Test Tanks, 1st Branch, Test Tank

Commitee, The Society of Naval Architects of Japan, Feb. (1933).

Tsuchiya, T. et al: Fundamental Performance of a New Circulating Water

Channel, Mitsui Shipbuilding Techical Reports, No.73 (1970).

Tomiyama, T. et al: On a New Circulating Water Channel in Nippon Kokan K.K.,

Jour. of The Society of Naval Architects of Japan, No.543 (1975).

Ishiguro, Y.: On a New Circulating Water Channel, Jour. of The Society of Naval Architects of Japan, No.543 (1975).

Marine Environmental Research Institute: Catalogue 1983-84, Japan Shipbuilding Development Foundation (1984).

Tanaka, H. & Abe, M.: Testing Methods and their Applications, Symposium on

Development of Ship Hull Forms and Test Tanks, 1st Branch, Test Tank Commitee,

The Society of Naval Architects of Japan, Feb. (1983).

13) Takahei, T.: Appraisal of Flow Visualization for Development of Ship

Hydrodynamics, 3rd Int. Symp. on Flow Visualization, University of Michigan,

Sept., 1933, Springer, Berlin (1983).

Takahei, T.: Ship Model Testing Methods and Measuring Techniques in a Water

Channel, 537th Seminar Text, The Japan Society of Mechanical Engineers (1934).

Laudan, J.: The Influence of the Propeller on the wake Distribution as

Established in a Model Test, Proceedings of SNAME, -81 Symposium (1981).

Hoshino, T. et al: Application of 3-Component LDV to Flow Measurement in

Cavitation Tunnel, Int. Symp. on Fluid Control and Measurement, Tokyo, Sept.

(1985).

Tagori, T. et al: A design of Turbulence-Reduced Circulating Water Channel, Reports of the Circulating Water Channel Group of Japan, 63-5, June (1932).

Asanuma, T. (ed.): A Handbook for Flow Visualization, Asakura-Books, p.72 (1977).

(30)

12-C.W.C. Seminar 1985

3. CHARACTERISTICS OF CIRCULATING WATER CHANNEL

by Michihito Ogura*

1-1 INTRODUCTION

In Japan, since a small sized horizontal type of the CWC was established at

Tokyo University of Fisheries in 1951, 62 units of large and small CWCs have been established (cf. Table 3-1-1) for the purpose of investigation in naval

architecture, ocean, and fisheries engineering. These are utilized in various

field as 34 units for naval architecture, 14 units for ocean engineering, 12

units for fisheries engineering, 4 units for aviation mechanical engineering, 6

units for the investigation of sports, and 5 units for other purposes. As

mentioned above, the TIC is utilized actively as a tool of research and

develop-ment in a wide field. ' The main reasons for such active use are

Great strides in performance of the CWC.

The appearance of testing machines of small size and high accuracy as a result of the new development of measuring instruments.

Economical resources for research and development have been improved. The CWC requirements differ with different uses, but generally the performance

of the CWC has been made greatly improved since 1951. The improved performance

of the CWC can be considered as follows.

The uniformity of the velocity distribution. Decrease of specific turbulence.

Decrease of waves (steady wave) at the surface of the measuring section. Control of the incline at the water surface.

Decrease of the periodic heaving (surging) at the water level at the

measuring section.

Removal of the cavity which makes trouble in observation.

Decrease of the ripples at the surface of the measuring section.

The progress of the CWC in performance can be divided broadly into 4 periods.

The CWC in the first period was the small sized horizontal type. The measuring

sections were 1.0 - 1.2 m for shipbuilding, and 0.8 - 2.0 m for fisheries. The

maximum velocity was about 1.0 m/s. The output of the driving motor was usually

less than 10 kw. The CWC of this period had no contraction nozzle at the upstream of the measuring section, but had the honey comb through it. It is said that the speed deflection at the measuring section was about 10 %, and the

velocity drop was about 20 %. The incline at the surface of the water, surging,

and steady waves were not paid any attention under the establishing of the CWC

(University of Tokyo (former style), Hiroshima University (former style), Hitachi Shipbuilding Co, Ltd. (former style), and Sasebo Heavy Industries Co, Ltd. (former style).).

The second period began in 1956 at the Defense Academy, and the CWC was the

big sized horizontal type or the small sized vertical type, and adopted the contraction nozzle so that the uniformity and high speed of the velocity

distribution were measured. For the horizontal type, the measuring section was

1.0 - 2.0 m, the driving motor output was 30 - 75 kw, the necessary volume of

water was 40 - 140 tons, and the maximum velocity was about 2.0 m/s, which was a

big size comparatively. For the vertical type of the water channel, it was a

small size and the measuring section was less than 1 m. By the CWC of this

period, the improvement in performance of the CWC had been measured, the

adoption of the punched metal for the uniformity of the velocity distribution,

establishment of flap type suppressing plate for the control of the steady waves, the boundary layer blow-in for the equality of the surface flow, and

furthermore, the method of sucking the net water flow to the surface were tried,

and the basic data for the improvement of the performance were obtained. The speed defiletion at the measuring section of the CWC of this period was upgraded

up to 4 %. (The Defense Academy, University of Tokyo, Tokyo University of

Mercantile Marine, Niigata Engineering Co., Ltd., Kawasaki Heavy Industries Co., Ltd., University of Osaka Prefecture, Kobe Shosen Daigaku, Nagasaki Institute of Applied Science, and Ship Research Institute, Ministry of Transport.)

The third period appeared with the strides in improvement of economy in Japan, the vertical type of CWC of a big size which was established at the

Research Center of Mitsui Engineering & Shipbuilding Co., Ltd. in 1970. As the

maximum velocity was 2.0 - 3.0 m/s, the water channel was 5.0 - 8.0 m high in order to prevent cavities forming. The measuring section was 2.0 - 3.0 m and

had 3-dimensional contraction nozzle so that the capacity was 200 - 400 tons,

which was quite a big size. The driving motor output was also a big one, 75

-110 kw. (Mitsui Engineering & Shipbuilding Co., Ltd., Hakodate Seimo Sengu Co., * West Japan Fluid Engineering Laboratory Co., Ltd.

(31)

Ltd., Nippon Kokan K. K., Nippon Shipbuilding Technical Center, and Sasebo Heavy

Industries Co., Ltd. (new style).) The establishment of the CWC during this

period was based on each of the basic data of the water channel during the second period, and some additional devices were adopted for the uniformity of

the velocity distribution.

Furthermore, this CWC made high velocity

comparatively, the forming of cavities or surging were picked up as a problem so that after establishment of the CWC, some parts were reconstructed, which were

the good data for the CWC establishing in the next (fourth) period. Also during

this period, the super big size of the horizontal type of the CWC was

established which shows the extent of the use of the CWC.

The fourth period began in 1979, when the CWC was made, by considering the economical and working performance, as the big measuring section and the small

main body, because of power saving after the oil shock. These water channels

adopted the 2-dimensional contraction nozzles, which were driven by two

impellers, the uniformity of velocity distribution, steady waves, decrease of

surging, and deaeration at high-speed, were devised. The measuring section of

most of the CWCs was 1.5 - 2.0 m, the necessary volume of water was 20 - 80

tons, which was a middle size. Nowadays, the maintenance and care of the CWC is

decreased by using stainless steel material. The driving motor output is 7.5

-44 kw, the maximum velocity is 2.2 - 2.8 m/s, which shows that this CWC has

upgraded the power performance and is highly efficient, as the speed defection

at the measuring section is 1 - 2 %, the surging steady waves and forming of

cavities are little. By these performances, automatic driving, measurement, and

analysis system by computer is adopted, and it is making progress in performance

of research and development. (West Japan Fluid Engineering Laboratory Co., Ltd.

(5 units), Kobe Technical High School, Hiroshima University, Tokai University,

Research Institute of Ishikawajima-Harima Heavy Industries Co., Ltd., Tsuneishi

Shipbuilding Co.,

Ltd. (2 units),

Tanaka Sangyo Co.,

Ltd.,

Kagoshima

University.)

With the extent of the use of the CWC, the CWC of a large size for the ocean simulation (the main body is 50 - 60 m), of a small size and capable to seal up for the aerial machine, of the high speed CWC which has free surface, for the tests of oceanic life made by FRP material, and for the swimming training, were established. As above mentioned, many institutes have made efforts so that the performance of the CWC in Japan has been upgraded step by step. Then the CWC has come to be used in a wide range as an instrument for

examination or research, which could never be thought of thirty years ago. 3-2 CHARACTERISTICS OF FORM AND MEASUREMENTS OF CIRCULATING WATER CHANNEL

3-2-1 Form and Construction

The CWC in Japan (cf. Table 3-1-1) consists of a waterway of the

punched metal air bubble

extractor 4th corner an

guide vane

3rd conner and guide vane

oney corn

surface flow accelerator

measuring rail air bubble

uppressing plat extractor

over flow perforat n

steady wave

control wi igh-s ed flow air

bu le acceleraotor 1st corner and guide vane manhole for examination stator

Fig. 3-2-1 Schematic Diagram of the Vertical Circulating Water Channel

-14-driving

shaft 2nd corner and guide vane

-- impeller

////,ully

(32)

Table 3-1-1

A

Lists of Circulating Water Channels in Japan

1

Tokyo University of Fisheries,

Faculty of Fisheries

For the research of fishing nets.

2

University of Tokyo,

Faculty of Naval Architecture

For the research of shipbuilding. (Moved to Univ. of Tokyo from Mitsubishi Heavy Industries Co., Ltd. in 1964.)

3

The Fisheries Agency,

Institute of Fisheries

For the researches of fishing boats and nets. (Reconstructed in 1980.)

4

Kagoshima University,

Department of Fisheries

For the researches of fish and fishing nets. (Motor output was changed later.)

5

Hitachi Shipbuilding Co., Ltd.,

Research Institute

For the research of shipbuilding.

6

Hiroshima University,

Faculty of Naval Architecture

(Moved to Kanazawa

Institute of Technology in 1982.)

7

The Defense Academy

8

Hokkaido University

Department of Fisheries

For the research of fishing nets. (Made it longer and reconstructed in 1974.)

9

Ship Research Institute, Ministry of Transport

10

Sasebo Heavy Industries Co., Ltd.

For the research of shipbuilding. (Set rotor in 1973.)

11

University of Tokyo,

Department of Marine Engineering

For the research of shipbuilding, ocean, propeller, machinery, sports, and so forth.

12

Ibaragi University, Department of Engineering

Moved to Hitachi shipbuilding Co., Ltd. in 1972.

13

Nagasaki Shipbuilding University

(Nagasaki Institute of Applied Science)

14

The Tokyo University of Mercantile Marine,

For the research of navigation.

Faculty of Navigation

15

Nippon Kokan K. K., Research Institute

16

Niigata Engineering Co., Ltd.

17

Mitsui Engineering & Shipbuilding Co.,

Research Institute

Ltd.,

For the researches of shipbuilding and ocean.

18

Kawasaki Dockyard Co., Ltd., Research Institute

(33)

19

University of Osaka Prefecture,

Department of Naval Architecture

20

Shimonoseki Chuo Technical High School

21

Kobe University of Mercantile Marine

22

Osaka University, Department of Engineering

23

Hakodate Seimo Sengu Co., Ltd.

24

Nippon Kokan K. K., Research Institute

25

Yuge Higher Mercantile Marine College

26

Toba Higher Mercantile Marine College

27

Hiroshima Higher Mercantile Marine College

28

Oshima Higher Mercantile Marine College

29

Toyama Higher Mercantile Marine College

30

Tokyo University of Fisheries

31

Japan Marine Science and Technology Center

32

japan Foundation for Shipbuilding Advancement

33

Institute of Ocean Environment Technology

34

Nihon Humanities and Science University

35

Tsukuba University, Department of Physical Science

36

West Japan Fluid Engineering Laboratory Co, Ltd.

37

Aoyama Gakuin University,

Department of Science and Engineering

38

Tokyo University of Fisheries

39

Kobe Technical High School,

Faculty of Ship Engineering

40

West Japan Fluid Engineering Laboratory Co., Ltd.

41

Hitachi Shipbuilding Co., Ltd., Research Institute

42

(34)

43

Hiroshima University,

Department of Naval Architecture

and Ocean Engineering

44

Tokai University, Department of Ocean Engineering

45

National Aerospace Laboratory, Aero Engine Division

46

47

Sasebo Heavy Industries Co., Ltd.

48

Marine Ecology Research Institute

49

Ishikawajima-Harima Heavy Industries Co., Ltd.,

Research Institute

50

Central Research Institute

of Electric Power Industry

51

Kyushu University,

Research Institute for Applied Mechanics

52

93

54

55

National Institute of Fitness and Sports in Kanoya.

56

57

Nippon Kaiji Kyokai, Research Institute.

58

Komatsu Ltd., Technical Research Center.

59

Tsuneishi Shipbuilding Co., Ltd.

60

Tsuneishi Shipbuilding Co., Ltd.

61

Tanaka Sangyo Co., Ltd.

62

Kagoshima University, Faculty of Fisheries.

(35)

Table 3-1-1

Lists of Circulating Water Channels in Japan (continued)

No. H-1 H-2 H-3 1951 horizontal 4.25/1.80/0.6 2.0/0.8/0.6 2.25/0:7 No No 2 2 1953 horizontal 7.2/3.0/1.0 2.0/1.2/0.8 3.75/0.8 No No 1 (1964) 3 1955 horizontal 7.2/2.8/1.0 2.9/1.20/0.8 3.75/1.0 No No 1 4 1955 symmetrical horizontal 14.0/7.1/1.0 2.0/2.0/0.8 7.5/1.0 No No 2 paddle wheel 5 1956 horizontal 11.5/3.4/1.5 6.1/1.2/1.2 30.0/1.2 No No 1 6 1956 horizontal 6.25/3.0/1.0 3.0/1.2/0.82 2.2/1.0 No No 1 7 1956 horizontal 9.8/4.5/3.0 6.0/1.2/1.2 30.0/1.8 3-D nozzle No 1 8 1956 symmetrical horizontal 14.0/7.1/1.0 2.0/2.0/0.8 7.5/1.0 No No 2 paddle wheel 9 1964 vertical 7.65/1.1/2.6 2.2/0.6/0.45 5.0/2.0 3-D nozzle No 1 10 1965 horizontal 7.9/2.5/1.5 4.0/1.5/1.3 7.5/1.0 No Rotor 1 11 1966 horizontal 11.0/4.2/1.65 5.55/1.5/1.1 30.0/1.8 3-D nozzle boundary layer blow in 1 12 1966 vertical 5.5/1.2/2.6 1.8/0.6/0.45 3.75/1.2 3-D nozzle No 1 13 1966 vertical 7.7/1.1/2.9 2.4/0.8/0.6 7.5/2.0 3-D nozzle

rotor filled with water

1 (est. 1981) 14 1966 horizontal 9.3/4.1/2.2 3.0/1.2/0.75 19.0/2.0 3-0 nozzle boundary layer blow in 1 15 1966 horizontal 8.2/4.0/1.8 3.7/1.2/0.75 22.0/1.7 3-11 nozzle blow in rotor (1975) 1 16 1970 horizontal 12.7/4.6/1.7 6.5/1.5/1.2 37.0/2.0 3-0 no No 1 17 1970 vertical 16.2/4.2/6.8 5.5/2.0/1.2 75.0/3.0 3-D nozzle

rotor of blow in and filled with water(est.1981)

1 H-4 No 3.5 No 14.0 No 14.0 No 32.0 No 27.0 No 15.0 upstream 40.0 No 32.0 No 10.0 No 30.0 up & down 47.0 streams 2 No 10.0 upstream 15.0 1 up & down 30.0

streams 2 up & down

69.0

streams 2 up & down

250.0

(36)

18 1971 horizontal 19 1972 horizontal 20 1972 horizontal 21 1973 horizontal 22 1973 horizontal 23 1.973 vertical 24 1974 vertical 25 1974 horizontal 26 1974 horizontal 27 1974 horizontal 28 1974 horizontal 29 1974 horizontal 30 1977 horizontal 31 1978 horizontal 32 1978 vertical 33 1978 horizontal 16.0/8.0/2.8 12.0/4.2/2.15 6.0/2.58/0.9 14.0/6.0/2.5 6.0/2.0/1.3 6.5/1.5/1.0 2.2/0.8/0.7 5.0/1.5/1.1 75.0/2.5 3-D nozzle 37.0/2.3 3-D nozzle 7.5/1.4 3-D (diesel) nozzle 30.0/2.0 3-D

(changed in 1985)

No No

blow in

1

up & down streams 2 upstream 1

180.0 50.0

up & down

8.0

streams 2 up & down

50.0 streams 2 No 40.0 up & down 250.0

streams 2 up & down

330.0

streams 2 up & down

30.0

streams 2 up & down streams 2 up & down streams 2 up & down streams 2 up & down streams 2 up & down streams 2 up & down streams 2 up & down streams 2

No 30.0 30.0 30.0 30.0 20.0 18.0 80.0 3000.0 no 12.0/5.0/2.5 3.6/1.6/1.0 4.5/0.85 3-D no No 1 20.0/4.24/5.45 8.0/3.0/1.2 90.0/2.5 3-D nozzle 2 rotors 1 26.6/4.0/7.2 9.0/2.5/1.325 110.0/2.5 3-D nozzle both of

blow in & out

1 9.61/3.96/2.2 3.5/1.2/0.8 22.0/2.0 3-D nozzle

1 (remodeled in 1980.) 9.61/3.96/2.2 3.5/1.2/0.8 22.0/2.0 3-D nozzle rotor 1 9.61/3.96/2.2 3.5/1.2/0.8 22.0/2.0 3-D no rotor 9.61/3.96/2.2 3.5/1.2/0.8 22.0/2.0 3-D nozzle

1 9.61/3.96/2.2 3.5/1.2/0.8 22.0/2.0 3-D nozzle rotor (rem. in 1983) 1 7.3/3.0/2.2 2.6/1.2/0.8 7.5/1.2 3-D no No 1 9.58/3.9/1.75 2.0/0.6/0.6 37.0/2.5 3-D nozzle No 1 16.175/2.52 5.0/1.4/0.84 74.0/5.5 3-D blow out 1 /5.68 nozzle 77.0/15.5/7.9 60.0/3.8/4.3 200.0/1.5 2-D nozzle blow out 1

(37)

34 1978 horizontal 13.0/5.0/2.0 3.0/1.0/1.0 2.2/2.0 3-0 nozzle

1 35 1979 vertical 13.7/2.4/4.4 5.5/2.0/1.2 55.0/2.5 3-0 nozzle rotor 1 36 1979 vertical 13.7/2.0/4.5 5.3/2.0/1.0 30.0/2.0 2-D nozzle

2 37 1979 vertical 6.1/3.0/3.17 2.2/0.6/0.5 30.0/3.5 3-0 nozzle deformed rotor 1 38 1980 horizontal 17.0/6.05/2.60 7.0/1.45/1.2 37.0/2.0 3-0 nozzle rotor 1 39 1980 vertical 8.7/1.5/3.0 4.0/1.5/0.7 7.5/1.0 2-0 nozzle rotor 2 40 1980 vertical 11.9/3.0/3.0 5.1/3.0/1.0 22.0/0.4 No No 2 41 1981 horizontal 14.2/6.5/2.0 6.0/1.6/1.3 55.0/2.0 3-0 nozzle

1 42 1981 vertical 9.0/1.5/2.85 3.7/1.5/0.8 15.0/2.0 2-0 nozzle

2 43 1982 vertical 9.7/1.4/3.82 4.0/1.4/0.9 11.0/1.3 2-D nozzle

2 44 1982 vertical 8.5/1.4/3.82 2.4/1.4/0.9 11.0/1.3 2-D nozzle No 2 45 1982 vertical stainless 3.62/0.45/1.35 1.20/0.2/0.2 1.5/2.0 3-D nozzle No 1 46 1982 vertical 14.8/2.0/5.2 5.5/2.0/1.0 44.0/2.3 2-0 no

2 47 1983 vertical 17.5/2.8/7.2 6.0/2.0/1.2 45.0/2.0 3-0 nozzle combayor belt 1 48 1983 vertical F.R.P. 7.7/0.6/2.7 2.6/0.8/0.6 15.0/2.0 2-0 nozzle No 2 49 1983 vertical 13.2/1.8/0.6 4.7/1.8/0.9 44.0/2.9 2-0 nozzle 2 rotors filled with water 2 50 1984 horizontal 3.0/1.5/1.4 1.15/0.5/1.0 5.5/0.5 No No 1 F.R.P. upstream 30.0 1 up & down 60.0

streams 2 up & down

70.0

streams 2 up & down

6.8

streams 2 up & down

130.0

streams 2 up & down

25.0 streams 2 No 45.0 up & down 110.0

streams 2 up & down

22.0

streams 2 up & down

30.0

streams 2 up & down

20.0

streams 2 up & down

1.0

streams 2 up & down

80.0

streams 2 up & down

180.0

streams 2 up & down

17.0

streams 2 up & down

70.0

streams 3

No