propeller

1. © MAN Diesel A/S
L/7396-6.0/0601 (3250/BGJ)
Load Lines - Freeboard Draught
T T
ropical
S Summer
W W
inter
W
NA W
inter - theNorth
Atlantic
D L
D: Freeboard draught
Seawater
Freshwater
Danish
load mark
TF
F
D
Freeboard deck

2. © MAN Diesel A/S
L/7397-8.0/0601 (3250/BGJ)
Hull Dimensions
Length between perpendiculars . . . : L
Length on waterline. . . . . . . . . . . . . : L
Length o : L
Breadth on waterline . . . . . . . . . . . .: B
Draught . . . . . . . . . . . . . . . . . . . . . . : D= 1/2 (D +D )
Midship section area . . . . . . . . . . . .: A
PP
WL
OA
WL
m
F A
verall . . . . . . . . . . . . . . . . .

3. © MAN Diesel A/S
L/7399-1.0/0601 (3250/BGJ)
Hull Coefficients of a Ship
LW
L
AW
L
BW
L
D
AM
W
aterlineplane
LPP
,
Midship section coefficient . . . . . .
V
olume of displacement. . . . . . .
W
aterlinearea. . . . . . . . . . . . . . .
Block coefficient L based. . . . .
W
aterplanearea coefficient. . . . .
WL
Longitudinal prismatic coefficient
:
:
: =
: =
: =
: =
A
C
C
C
C
W
L
B
W
L
M
P
L B
WL x x D
WL
B x D
WL
A x L
M WL
L B
WL WL
x
AWL
AM

4. © MAN Diesel A/S
L/7238-6.0/0601 (3250/BGJ)
Total Ship Towing Resistance
RT = RF + RW + RE + RA
RF
V
RA
V
RW
RE
Ship speed V
% of R
T
T
ypeof
resistance
R
A
R
W
R
E
R
F = Friction
= W
ave
= Eddy
= Air
High
speed
ship
Low
speed
ship
45- 90
40- 5
5- 3
10- 2

5. © MAN Diesel A/S
L/7763-3.0/0601 (3250/BGJ)
The “Wave Wall”
Ship Speed Barrier
20 knots
Normal service point
Ship speed
New service point
kW

6. © MAN Diesel A/S
L/7400-3.0/0601 (3250/BGJ)
The Propulsion of
a Ship - Theory
Efficiencies
1 t
1 w
Relativerotativeefficiency . . . . . :
Propeller efficiency - open water :
Propeller efficiency - behind hull : =
Propulsiveefficiency. . . . . . . . . : =
Shaft efficiency. . . . . . . . . . . . . :
T
otal efficiency
. . . . . . . . . . . . . . :
_
_
x
x
Power
Effective(T
owing)power. . . . . . . : P = R V
bythepropeller to water . . . . . . : P = P /
Power delivered to propeller. . . . : P = P /
Brakepower of main engine . . . : P = P /
E T
T E
D T
B D
x
Hull efficiency
. . . . . . . . . . . . . . . : =
Thrust power delivered
H
H
B
D
S
T B
S
B
0 R
T
---- ---- x ---- x ---- x x x x x
= = = =
P P P P
B T D B
P P P P
E E T D
H
S H 0 R S
H
R
0
B
Velocities
Ship’s speed . . . . . . . . . . . . . . . . : V
Arriving water velocity to propeller. : V
Effectivewakevelocity
. . . . . . . . . . : V = V_V
A
W A
Forces
T
owing resistance. . . . . . . . . . . . . : R
Thrust force. . . . . . . . . . . . . . . . . : T
Thrust deduction fraction . . . . . . . : F= T_R
T_R
T
T
T
T
Thrust deduction coefficient . . . . . : t =
W
akefraction coefficient. . . . . . . . : w =
(Speed of advanceof propeller)
V_V
V
A
VA
V
VW
PD
PE
PT PB
V
T
RT
F

7. © MAN Diesel A/S
L/7239-8.0/0601 (3250/BGJ)
Propeller Types
Controllable pitch propeller
(CP-Propeller)
Fixed pitch propeller
(FP-Propeller)
Monobloc with
fixed propeller
blades
(copper alloy)
Hub with a
mechanismfor
control of the
pitch of the blades
(hydraulically activated)

8. © MAN Diesel A/S
L/7401-5.1/0201 (3250/BGJ)
Obtainable Propeller Efficiency
- Open Water
0.3
0.2
0.4
0
0.6
0.1
0.6
0.5
V
n xd
A
Advance number J =
0.4 0.5
0.2 0.3
0 0.1
0
0.7
Propeller
efficiency
Reefers
Container ships
Small tankers
20,000 DW
T
Large tankers
>150,000 DW
T
n (revs./s )
1.66
2.00
0.7

9. © MAN Diesel A/S
L/9802-8.1/0201 (3250/BGJ)
Propeller Design - Influence of
Diameter and Pitch
110 120
100 r/min
130
Shaft power
80 90
8,800
70
8,700
8,900
9,100
8,600
8,500
9,400
0.95
9,200
9,300
9,000
d =Propeller diameter
p/d =P
itch/diameter ratio
Power and speed curve
for various propeller
diameters d with
optimump/d
Propeller speed
Power and speed curve
for thegiven propeller
diameter d = 7.2mwith
different p/d
80,000 dwt crudeoil tanker
Design draught = 12.2 m
Ship speed = 14.5 kn
9,500
0.90
0.85
0.80
0.71
1.00
0.60
0.75
d
0.65
0.55
6.8 m
p/d
0.67
7.2 m
6.6 m
7.4 m
7.0 m
0.70
0.68
0.69
0.50
p/d
p/d
d
kW

10. © MAN Diesel A/S
L/6846-7.0/0701 (3250/BGJ)
Movement of a Ship´s
Propeller, with Slip
Sx p x n
Vor VA
Pitch p
n
0.7 x r
r
d
p x n
Slip
The apparent slip ratio : S = = 1 _
A
The real slip ratio : S = = 1 _
R
p x n _V V
p x n p x n
A A
p x n _V V
p x n p x n

11. © MAN Diesel A/S
L/6645-5.0/0701 (3250/BGJ)
Movement of a Corkscrew,
without Slip
V
elocity of corkscrew: V= p x n
Pitch p
Wine bottle
Corkscrew Cork
V
n

12. © MAN Diesel A/S
L/5537-1.1/0201 (3250/BGJ)
Ship Speed Performance at
15% Sea Margin
(Logarithmic scales)
15.6 knots
115% power
15.0 knots
100% power
15% Sea
margin
Power
Ship speed
Propeller curve for clean
hull and calmweather
15.0 knots
115% power
B
A

13. © MAN Diesel A/S
L/5408-5.1/0201 (3250/BGJ)
Propeller Speed Performance
at 15% Sea Margin
15.6 knots
115% power
15.0 knots
100% power
15% Sea
margin
Slip
Propeller speed
Propeller curve for clean
hull and calmweather
15.0 knots
115% power
Power
(Logarithmic scales)
A
B’
B

14. © MAN Diesel A/S
L/5481-7.1/0201 (3250/BGJ)
Propeller Speed Performance at
Large Extra Ship Resistance
(Logarithmic scales)
15.0 knots
100% power
12.3 knots
50% power
Propeller curve
for clean hull and
calmweather
12.3 knots
100% power
Propeller speed
Propeller curve
for fouled hull
and heavy seas
LR
Power
10.0 knots
50% power
Slip
HR
HR= Heavy running
LR= Light running
D’
C
A
D

15. © MAN Diesel A/S
L/8554-2.0/0601 (3250/BGJ)
Service Data over a Period af a Year
Returned from a Single Screw Container Ship
BHP
21,000
18,000
15,000
12,000
9,000
6,000
76 80 92
84 96
88 100
Shipspeed
knots
Shaft power
Cleanhull and draught D
D = 6.50 m
D = 5.25m
D = 7.75 m
Source: Lloyd's Register
MEAN
F
A
Averageweather 3%
E
xtremely good weather 0%
E
xtremely bad weather 6%
Propeller speed
Apparent slip
10%
6%
Heavy
running
2%
-2%
13
16
19
22
C
B
A
C
B
A
r/min

16. © MAN Diesel A/S
L/7606-5.1/0201 (3250/BGJ)
Measured Relationship Between Power,
Propeller and Ship Speed During Seatrial
Propeller curve
"tail w
ind"
Reefer ship
SMCR: 13,000 kWx 105 r/min
Wind velocity : 2.5 m/s
W
ave height : 4 m
Propeller/engine speed
100
90
105
85
100
95
80
101
99 103 105 % SMCR
102
97 98
96 104
Heavy
running
Engine
"propeller curve"
Propeller curve
"head
w
ind"
Propeller design
light running
*20.5
21.5
*
20.5
*
*
20.8
*21.2
*22.0
21.1 *
7
5
1
3
4
Shaft power, % SMCR
22.3 *
21.8
*
SMCR
*21.1
Head wind
T
ail wind
(Logarithmic scales)

17. © MAN Diesel A/S
L/71325-5.1/0701 (3250/BGJ)
Engine Load Diagram -
Acceleration
80 100 105
85
50
75
65 90 95
60
60
70
80
90
mep
110%
Engine speed, % A
40
100
Engine shaft power, % A
100%
90%
80%
70%
60%
O
A 100% referencepoint
M Specified engineMCR
O Optimising point
110
Logarithmic Scale

18. © MAN Diesel A/S
L/6847-9.1/0701 (3250/BGJ)
Relationship Between Linear Functions
Using Linear Scales and Power Functions
Using Logarithmic Scales
A. Straight lines
in linear scales
a
2
1 2
0
1
0
b
y = ax + b
B. Power function curves
logarithmic scales
in
P= engine power
c = constant
n = enginespeed
log(P) = i x log(n)+ log(c)
y = ax + b
P= c x ni
i = 1
i = 2
i = 3
y = log (P)
i = 0
X= log (n)
y = log (P)= log (c x n )
i
y

19. © MAN Diesel A/S
L/5417-3.1/0701 (3250/BGJ)
Ship Propulsion Running
Points and Engine Layout
Engine speed
Power
MP
Seamargin
(15% of PD)
2 6
SP
2 Heavy propeller curve-
hull and heavy weather
6 Light propeller curve-
hull and calmweather
MP: Specified propulsionMCRpoint
SP: Servicepropulsion point
PD: Propeller designpoint
PD`: Alternativepropeller design point
LR
: Light running factor
HR
: Heavy running
fouled
clean
HR
PD´
PD
E
nginemargin
(10% of MP)

20. © MAN Diesel A/S
L/7116-6.1/0701 (3250/BGJ)
Engine Load Diagram
Load diagram
Line 1: Propeller curve through
optimising point (O)
layout curvefor engine
Line 2: Heavy propeller curve
fouled hull and heavy seas
Line 3: Speed limit
Line 4: T
orque/speed limit
Line 5: Mean effective
pressurelimit
Line 6: Light propeller curve clean
hull and calmweather
layout curvefor propeller
Line 7: Power limit for
continuous running
Line 8: Overload limit
Line 9: Seatrial speed limit
Line 10: Constant mean effective pressure(mep) lines
80 100 105
85
50
70 75
65 90 95
60
60
70
80
90
mep
110%
40
2
4
9
7
8
5
100
Engine shaft power, % A
6
100%
90%
80%
70%
60%
1
10
3
O
A 100% reference point
M Specified engine MCR
O Optimising point
110

21. © MAN Diesel A/S
L/7402-7.1/0701 (3250/BGJ)
Example 1 with FPP -
Engine Layout without SG (normal case)
Point Aof load diagram
Line 1: Propeller curve through
optimising point (O)
Line 7: Constant power line through
specified MCR(M)
Point A: Intersection between
lines 1 and 7
Power
A=M=MP
Propulsion and engine service
curve for heavy running
7
S=SP
O
2
1
6
M: Specified MCR
of engine
S: Continuous service
rating of engine
O: Optimising point
of engine
A: Reference point
of load diagram

22. © MAN Diesel A/S
L/7403-9.1/0701 (3250/BGJ)
Example 1 with FPP -
Load Diagram without SG (normal case)
Engine speed
A=M
Propulsion and engine service
curve for heavy running
3.3% A
5
6
2
4
Power 1
S
7
O
5
6
3
4 1
7
2
5% A
5% L1
M: Specified MCR
of engine
S: Continuous service
rating of engine
O: Optimising point
of engine
A: Reference point
of load diagram

23. © MAN Diesel A/S
L/7404-0.1/0701 (3250/BGJ)
Example 2 with FPP -
Engine Layout without SG (special case)
Point Aof load diagram
Line 1: Propeller curve through
optimising point (O)
Line 7: Constant power line through
specified MCR(M)
Point A: Intersection between
lines 1 and 7 Engine speed
M=MP
Propulsion and
engine service curve
for heavy running
7
S=SP
6
2
1
O
Power
A
M: Specified MCR
of engine
S: Continuous service
rating of engine
O: Optimising point
of engine
A: Reference point
of load diagram

24. © MAN Diesel A/S
L/7405-2.1/0701 (3250/BGJ)
Example 2 with FPP -
Load Diagram without SG (special case)
M
Propulsion and engine service
curve for heavy running
3.3% A
5
6
2
4
1
S
7
5
6
3
4 1
7
2
5% A
A
O
Engine speed
Power
M: Specified MCR
of engine
S: Continuous service
rating of engine
O: Optimising point
of engine
A: Reference point
of load diagram

25. © MAN Diesel A/S
L/7406-4.1/0701 (3250/BGJ)
Example 3 with FPP -
Engine Layout with SG (normal case)
Point Aof load diagram
Line 1: Propeller curve through
optimising point (O)
Line 7: Constant power line through
specified MCR(M)
Point A: Intersection between
lines 1 and 7
M: Specified MCR
of engine
S: Continuous service
rating of engine
O: Optimising point
of engine
A: Reference point
of load diagram
S
h
a
f
t
g
e
n
e
r
a
t
o
r
Propulsion curve
for heavy running
O
7
1 2
Engine service curve
for heavy running
MP
SG
6
S
SG
SP
Power A=M

26. © MAN Diesel A/S
L/7407-6.1/0701 (3250/BGJ)
Example 3 with FPP -
Load Diagram with SG (normal case)
S
h
a
f
t
g
e
n
e
r
a
t
o
r
Propulsion curve
for heavy running
3.3% A
S
5
6
2
4
1
7
O
5
6
3
4 1
7
2
5% A
5% L1
A=M
Engine service curve
for heavy running
MP
SP
Engine speed
Power
M: Specified MCR
of engine
S: Continuous service
rating of engine
O: Optimising point
of engine
A: Reference point
of load diagram SG
SG

27. © MAN Diesel A/S
L/7408-8.1/0701 (3250/BGJ)
Example 4 with FPP -
Engine Layout with SG (special case)
S
h
a
f
t
g
e
n
e
r
a
t
o
r
Propulsion curve
for heavy running
SG
6
1
7
2
M
Engine service curve
for heavy running
MP
SP
A
M´
Power
M: Specified MCR
of engine
S: Continuous service
rating of engine
O: Optimising point
of engine
A: Reference point
of load diagram

28. © MAN Diesel A/S
L/7438-7.1/0701 (3250/BGJ)
Example 4 with FPP -
Load Diagram with SG (special case)
S
h
a
f
t
g
e
n
e
r
a
t
o
r
Propulsion curve
for heavy running
3.3% A
SG
5
6
2
4
1
7
6
3
1
7
2
5% A
5% L1
Engine service curve
for heavy running
SP
A
M´
5
4
Engine speed
Power
M: Specified MCR
of engine
S: Continuous service
rating of engine
O: Optimising point
of engine
A: Reference point
of load diagram

29. © MAN Diesel A/S
L/7439-9.1/0701 (3250/BGJ)
Example 5 with FPP -
Load Diagram with SG (special case)

30. © MAN Diesel A/S
L/7440-9.1/0701 (3250/BGJ)
Influence of Different Types of Ship
Resistance on the Continuous Service Rating
8
5
9
3
2
1
7
4
90
85
95
75
70
85
105
100
110
80
90 95 100 105
S3
80 110
SP
100% ref. point (A)
Specified MCR(M)
6
S2
S1
S0
PD
Engine speed, % of A
A=M
Engine shaft power, % of A
PD: Propeller design point, clean hull and calmweather
S0: Clean hull and calmweather, loaded ship
S1: Clean hull and calmweather, ballast (trial)
S2: Clean hull and 15% seamargin, loaded ship
SP: Fouled hull and heavy weather, loaded ship
S3: V
ery heavy seaand wave resistance
Continuous service rating for propulsion with
a power equal to 90% specified MCR, based on:
Line1: Propeller curvethrough point A=M
Line2: Heavy propeller curve, fouled
hull and heavy weather, loaded ship
Line6: Light propeller curve, clean hull and
calmweather, loaded ship
Line6.1: Propeller curve, clean hull and
calmweather, ballast (trial)
Line6.2: Propeller curve, clean hull and
15% seamargin, loaded ship
Line6.3: Propeller curve, very heavy sea
and wave resistance