The objective of the project was to identify the various components and necessary calculations involved in diving and propulsion of a modern diesel-electric submarine. An analysis was done on a model submarine to verify the resistance, powering and propulsive efficiency of the vessel.
Diving and propulsion system of modern diesel-electric submarine
1. 1
UNIVERSITY
(Under Sec. 3 of UGC Act 1956)
DIVING SYSTEM AND PROPULSION SYSTEM OF SUBMARINE
A PROJECT REPORT
Submitted by
ARJUN ANTONY A
REG.NO. ANA13010
In partial fulfilment for the award of the degree
Of
BACHELOR OF ENGINEERING
In
NAVAL ARCHITECTURE AND OFFSHORE ENGINEERING
Guided by Mr. GOPI KRISHNA
AMET UNIVERSITY, CHENNAI 603112
2. 2
AMET
UNIVERSITY
(Under Sec. 3 of UGC Act 1956)
135, East Coast Road, Kanathur – 603 112. Chennai, INDIA.
CERTIFICATE
Certified that this is a bonafide
Work of minor project work done by
Mr. ARJUN ANTONY A.. Register No. ANA13010, Semester VI has done the Minor Project
during the year 2015-2016 for the degree B.E (Naval Architecture and Offshore Engineering)
Submitted for the examination held on 30th
April 2016 at AMET University, kanathur, Chennai.
Cdr. PRASANTH SINGHAL MR. GOPI KRISHNA
( HEAD OF DEPARTMENT ) ( ASSISTANT PROFESSOR )
NAVAL ARCHITECTURE AND NAVAL ARCHITECTURE AND
OFFSHORE ENGINEERING OFFSHORE ENGINEERING
3. 3
ACKNOWLEDGEMENT
It gives me immense pleasure to express my deepest sense of
gratitude and sincere thanks to my, esteemed guide, Mr. Gopi Krishna
(ASST.Professor, B.E.NA&OE), for his valuable guidance, encouragement
and help for completing this work.
I would like to express my sincere thanks to, Cdr. Prashanth
Singhal (HOD, B.E.NA&OE), for giving me this opportunity to undertake this
project.
Place: CHENNAI Student Name: Arjun Antony A.
Date:27.04.2016 Reg. No: ANA13010
4. 4
ABSTRACT
The main aim of this project is to carry out various calculations on a
model submarine of length: 32m which, uses diesel electric-drive powering propulsion.
The literature survey, comprises of illustrations of how diving and surfacing
occurs on a diesel electric-drive submarine, the general components of submarine hull,
General Arrangement Plan, various submarine control surfaces, degrees of freedom of
submarine motion and types of submarine propulsion.
The model submarines general arrangement plan was developed in autocadd
and weight distribution on-board was also calculated. Then resistance calculations
where calculated for model submarine using reference from ITTC-1957(using the 3RD
METHOD)and methodical series – “AEW(admiralty experimental works) 20 inch”
.Further propulsive efficiency and propulsion coefficients are estimates. Finally, the
force acting on the hydroplane and the force of buoyancy are calculated.
Summary of findings are mentioned below
∆= 235T
Resistance of bare hull=17.995 KN
Total resistance=29.149KN
Efficiency( )=73.8%
Propulsion coefficient =0.86
Force on hydroplanes=83121N
Buoyancy Force=2249.75KN
5. 5
INDEX
CONTENTS: Page no.
1. Introduction To Project………………………………….……….….4
2. Literature Survey………………………………………………....6-12
(i) Diving and surfacing……………………………….........6
(a)Diving……………………………………………….…7
(b)Surfacing ……………………………………………..8
(c)Submarine control surfaces…………………….…..9
(d)Hydroplanes……………………………………....….10
(e)Vents…………………………………………........….10
(f) Flood ports…………………………………….......…10
(ii) Types of submarine propulsion…………………….….11
(a)Diesel propulsion …………………………………...11
- Diesel electric drive powering propulsion….…..11
- Direct drive propulsion……………………..........11
(b)Nuclear propulsion…………………………………..12
(c)Electromagnetic propulsion(concept)…………......12
3. Theoretical Explanation……………………………………......13-14
(i) Weight distribution…………………………………...….13
(ii) Resistance calculation………………………………….13
(iii) Propulsive efficiency & propulsion coefficient….…....13
(iv) Force on hydroplane……………………………….…...14
(v) Buoyancy force……………………………………..…..14
4. Calculations………………………………………………...…...15-19
(i) Weight distribution…………………………………..15
(ii) Resistance calculation…………………………..….16
(iii) Propulsive efficiency & propulsion coefficient…...17
(iv) Force on hydroplane………………………………..18
(v) Buoyancy force……………………………..………..18
6. 6
5. Drawings……………………………………………....………........20-21
(i) Model general arrangement plan generation
(autocadd drawing)……………………..……………………20
(ii) General arrangement plan……………………………...…...21
6. Conclusion……………………………………………………………22
7. References………………………………………………………...…23
LIST OF TABLES
(i) table.4.1 – Weight Distribution (in MSEXCEL)…..………15
(ii) table.4.2 – Bare Hull Resistance calculation
(In MSEXCEL)...………………………..….…16
LIST OF FIGURES
(i) figure.1.1 - CG, CB &METACENTER………………....…....1
(ii) figure.1.2 - Compartments And Components Of
Basic Submarine….……………..5
(iii) figure.1.3 – Location Of Various Tanks……………….…..5
(iv) figure.2.1 – Diving and Resurfacing of Submarine……….6
(v) figure.2.2 – Flooding the main ballast system……………7
(vi) figure.2.3 – Emptying the main ballast system…………...8
(vii) figure.2.4 – ballast locations on submarine……………….9
(viii) figure.2.5 – various locations for main ballast tank……....9
(ix) figure.2.6 – action of hydroplane in submerging…………10
(x) figure.2.7 – working of nuclear propulsion………………..12
(xi) figure.2.8 – electromagnetic propulsion…………………...12
(xii) figure.2.8 – electromagnetic propulsion…………………...12
(xiii) figure.5.1-model general arrangement plan
(autocadd drawing)….20
(ix) figure.5.2-model general arrangement plan…………….21
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1. INTRODUCTION TO THE PROJECT
A submarine or a ship can float because the weight of water that it displaces Is
equal to the weight of the ship.
This displacement of water creates an upward force called the buoyant force and
acts opposite to gravity (which would pull the ship down).
A submarine can control its buoyancy, thus allowing it to sink and surface at will.
Three main types of submarines are:
1. Pleasure submarines(small, expensive, recreational use)
2. Scientific submarines(investigate sea-floor, collect biological samples)
3. Military submarines (naval wars, torpedo launch, etc.)
figure.1.1 - CG, CB & METACENTER
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figure.1.2 - Compartments And Components Of Basic Submarine
figure.1.3 – Location of Various Tanks in Modern Diesel Electric-Drive Boat
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2. LITERATURE SURVEY
(2.i) DIVING&SURFACING
Two ways to submerge a boat:
Dynamic diving
-dive by using the speed of the boat in combination with the
dive planes.
-always positive buoyancy.
Static diving
-dive by changing the buoyancy of the boat itself by letting water
into ballast tanks.
-positive buoyancy to negative buoyancy.
Modern military submarines use a combination of both.
figure.2.1 – Diving and Resurfacing of Submarine (Western And Russian Method)
[source : http://www.howstuffworks.com/diving_and_surfacing]
surfacing of submarine
10. 10
(2.i.a) DIVING:
When the submarine is on the surface, the ballast tanks are filled with air and the
submarine's overall density is less than that of the surrounding water.
As the submarine dives, the ballast tanks are flooded with water and the air in
the ballast tanks is vented from the submarine until its overall density is greater
than the surrounding water and the submarine begins to sink (negative
buoyancy).
Also, the hydroplanes are angled so that water moves over the stern, which
forces the stern upward; therefore, the submarine is angled downward.
figure.2.2 – Flooding the main ballast system (UK & Russian method)
11. 11
(2.i.b) SURFACING:
When the submarine surfaces, compressed air flows from the air flasks into the
ballast tanks and the water is forced out of the submarine until its overall density
is less than the surrounding water (positive buoyancy) and the submarine rises.
The hydroplanes are angled so that water moves up over the bow, which forces
the stern downward; therefore, the submarine is angled upward.
In an emergency, the ballast tanks can be filled quickly with high-pressure air to
take the submarine to the surface very rapidly.
figure.2.3 – Emptying the main ballast system (UK & Russian
method)
12. 12
(2.i.c) SUBMARINE CONTROL SURFACES
To control its buoyancy, submarines and submersibles have ballast tanks
(diving & surfacing) and auxiliary, or trimming tanks (control attitude), that
can be alternately filled with water or air.
MAIN BALLAST TANK LOCATION:
1. inside the pressure hull
2. outside the pressure hull as additional tanks
3. in between the outer hull and the pressure hull
figure.2.4 – ballast locations on submarine
figure.2.5 – various locations for main ballast tank
13. 13
(2.i.d) HYDROPLANES
The submarine has movable sets of short "wings" called hydroplanes(or diving
planes) on the bow or stern that help to control the angle of the dive.
Thereby, assisting in the process of submerging or surfacing the boat, as well as
controlling depth when submerged.
The hydroplanes in bow can be angled so that water moves over the stern,
which forces the stern upward; therefore, the submarine is angled downward.
Surfacing.
Vice versa in case of diving.
(2.i.e) VENTS
Valve fitted to the top of a submarine's ballast tanks to let air escape from the top
of the ballast tank.
(2.i.f) FLOOD PORTS
Openings for water to enter, at bottom of the tank.
figure.2.6 – action of hydroplane in submerging
14. 14
.
(2.ii) TYPES OF SUBMARINE PROPULSION
(2.ii.a) Diesel Propulsion
1. Diesel-electric drive powering propulsion
Long range fleet submarines(more power).
Four engines& generator
Two shafts
Full time electric drive for propeller shaft
Diesel engine directly coupled to large direct current generator
Power generated used to charge batteries or powering motors
When submerged motors draw current from batteries.
2. Direct-electric drive propulsion
Engine connected to motor/generator(which function as direct current generator
Output directed through switchboards, into batteries(keeping them charged)
To charge battery when boat is tied up (not moving)a second clutch connects
motor/generator to propeller shaft
Throw switches to battery position; takes power from battery, directs it to
motor/generator, driving propeller shaft
15. 15
(2.ii.b) Nuclear Propulsion
(2.ii.c) Electromagnetic Propulsion (concept)
figure.2.7 – working of nuclear propulsion
figure.2.8 – electromagnetic
propulsion
16. 16
3. THEORITICAL EXPLANATION
(3.i) WEIGHT DISTIBUTION
Estimated on the basis of general weight distribution percentages for SSK-type
(modern diesel-electric drive engine)
(3.ii) RESISTANCE CALCULATIONS
These were conducted in regard with the empirical formulas provided in ITTC-
1957 rules and regulations
Open water characteristics for propeller design for submarines are taken from
“methodical series – AEW(admiralty experimental works) 20 inch”
(3.iii) PROPULSIVE EFFICIENCY &PROPULSION COEFFICIENT ESTIMATION
PROPULSIVE EFFICIENCY,
( ) =
EFFECTIVE HORSE POWER(PE)
SHAT POWER(PS)
PROPULSIVE COEFFICIENT
- =
- ≈ PC x(0.07 to 0.14)
17. 17
(3.iv) FORCE ON HYDROPLANE
= . . ( ) . . .
(3.v) BUOYANCY FORCE
Buoyancy force( ) = . .
Volume of displacement ( )=
∆
.
F: force on hydroplane (Kg)
C: friction coefficient (c=0.1)
A: area of hydroplane (m )
a: angle of hydroplane (deg)
ρ: density of water (1025 Kg/m )
∆: displacement(T)
F B: buoyancy force
ρ: density of water (1025 Kg/m
∇: Volume of displacement (m )
g: acceleration due to gravity(9.81 m/s )
19. 19
(4.ii) RESISTANCE CALCULATIONS :
Frictional resistance coefficient values are taken from ITTC-1957
Total frictional resistance coefficient ,
C = C 1 + 1.5
.
+ 7
Total bare hull resistance ,
R = . C . ρ. A. V
table.4.2 – bare hull resistance calculation (in MSEXCEL)
20. 20
Therefore considering a speed of V= 12 KNOTS (6.1728 m/s);
1. BARE HULL RESISTANCE = 17.995 KN
2. TOTAL RESISTANCE (RT)= 35.987 KN
(with appendages)
3. Applying CORRECTION FACTOR (19%) for method 3
c = 6.83
4. FINAL RT=29.149 KN
(4.iii) PROPULSIVE EFFICIENCY &PROPULSION COEFFICIENT ESTIMATION:
1. Propeller efficiency
=
=
.
.
= . ≈ 73.8 %
2. Propulsion estimation:
• Open water characteristics for propeller design for submarines are taken from
“methodical series – AEW(admiralty experimental works) 20 inch”
• Values considered:
1. wT =0.26
2. t =0.04
3. nH =1.30
4. nO =0.65
5. nR =1.02
• V=12knots(6.1728m/s)
• = (1 − ) = . m/s
Power estimation,
• PD=PE/(n . n . n ) = .
• PE=R . V= 179.93 Kw
• PT= = 138.407 Kw
• PS = = 243.56 Kw
21. 21
=
=1.30 X 0.65 X 1.02
= 0.86 {∴ = . < . < . }
• Propeller blade loading,
T = =
.
.
=30.306 KN
Assume propeller diameter=1.5 m
∴Area=1.767m
ℎ , thrust loading per unit area = 17.15 KN/m
{ ∴ . / < 70 / }
• ≈ PC x(0.07 to 0.14)
. = 0.86 X 0.07 = .
. = 0.86 X 0.14 = .
( ) =0.0903
{Propulsive coefficient < Propulsive coefficient }
(4.iv) FORCE ON HYDROPLANE:
• = . . ( ) . . .
= 0.1 X 25 X sin(30) X 0.5 X 1025 X (2.572)
= 4237.85Kg =4.238 T=41.56KN
F: force on hydroplane (Kg)
C: friction coefficient (c=0.1)
A: area of hydroplane (m )
a: angle of hydroplane (deg)
ρ: density of water (1025 Kg/m )
22. 22
∴ Net downward force =2F [since, 2 forward dive-planes]
=2 X 41.56
=83.12KN
(4.v) BUOYANCY FORCE:
In open sea condition (submarine is neutrally buoyant):
1. ρ = 1025 Kg/m
2. ∆(displacement)= 235T = 235000 Kg
3. Volume of displacement (∇) =
∆
.
=
.
= 23.37
4. Buoyancy force(F ) = ρ. g.
=1025 X 9.81 X 23.37
=234991Kg=234.99T
=2294.75KN [∴ 1T = 9806.65 N]
∆: displacement(T)
F B: buoyancy force
ρ: density of water (1025 Kg/m
∇: Volume of displacement (m )
g: acceleration due to gravity(9.81 m/s )
25. 25
6. CONCLUSION
The primary goal of this report is to consider a model submarine (32m),
which is of diesel direct-electric and estimate diving and propulsion characteristics.
The following estimations were carried out:
(iii) weight distribution
(iv) resistance calculation
(v) propulsive efficiency &propulsion coefficient
(vi) force acting on hydroplane
(vii) buoyancy force
these results were calculated, recorded and verified.
To conclude, this project sheds light on varies aspects regarding submarine
hydrostatics, hydrodynamics and diving and propulsion system.
26. 26
7. REFERENCES:
1. Concepts In Submarine Design
(Roy Burcher &Louis Rydill)
2. Fundamentals Of Submarine Concept Design
(CAPT.Harry A.Jackson)
3. evaluation and experimental formulas for fully submerged resistance
(Mohd.Moonesun,Mehran Javadi)
4. Journal: Study on submarines & semisubmersibles