Marine Powering Prediction and Propulsors - Product Image

Marine Powering Prediction and Propulsors

  • ID: 2166993
  • Book
  • 195 Pages
  • Society of Naval Architects and Marine Engineers
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This book by Dr. Neil Bose is an excellent interpretation of the hydrodynamics of the prediction of ship powering performance of various types of ship propulsors. It is based on extensive studies carried out by Dr. Bose and his students over the last several years at the Memorial University of Newfoundland, Canada and his long association with the Institute for Ocean Technology (IOT), National Research Council of Canada. As a result of his International Towing Tank Conference (ITTC) technical committee membership, he has captured the accepted international state of the art of ship powering prediction.

Dr. Bose has extensively discussed most types of ship propulsors, including oscillating foils and wind-assisted propulsion devices. He has included a general discussion on ship resistance and the prediction of powering performance from model tests, primarily for conventional screw propellers. As a result of his experience with IOT, he has included the problems of screw propellers operating in ice, particularly with regard to strength. He has incorporated quite a complete list of references and has included examples to be worked by the reader. As such, the book should be particularly useful to students and those responsible for making powering predictions, especially to those getting started in the field.

This book is an excellent resource for nonconventional marine propulsors and should be particularly useful to naval architectural students and practicing naval architects.
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Chapter 1 Introduction
1.1. References
Chapter 2 Powering prediction – ITTC 1978 method and its derivatives
2.1 Outline of the ITTC 1978 method
2.2 Variations from the ITTC 1978 method used in practice
2.3 References
Chapter 3 Powering prediction - extrapolation directly from self-propulsion tests – written with
Sue Molloy
3.1 Method of testing and extrapolation
3.2 Form factor
3.3 An example of the method
3.4 Summary
3.5 Examples
3.6 Solutions (numerical examples)
3.7 References
Chapter 4 Ship powering performance extrapolation – reliability and accuracy
4.1 The ‘‘Law of Comparison’’
4.2 Form factor
4.3 The three tests
4.4 Quasi-steady self propulsion tests
4.5 Unsteadiness in testing
4.6 Uncertainty analysis
4.7 Conclusions – how the extrapolation process can be improved
4.8 References
Chapter 5 Ducted, Controllable Pitch, Contrarotating and Cyclic Pitch Propellers
5.1 Design
5.2 Design=performance example
5.2.1 Open propeller
5.2.2 Equivalent ducted propeller
5.2.3 Ducted propeller
5.2.4 Propeller requirements compared with engine performance
5.3 Controllable pitch propellers
5.4 Tandem and contrarotating propellers
5.5 Cyclic pitch propellers
5.6 Examples
5.7 Solutions (numerical examples)
5.8 References
Chapter 6 Surface piercing propellers
6.1 Performance prediction
6.2 Outline design example
6.3 Problems
6.4 Solutions (numerical examples)
6.15 References
Chapter 7 Podded propulsors
7.1 Design and performance issues
7.2 Geometric and methodical series data – pod shape; hub taper angle
7.3 Azimuthing and dynamic azimuthing performance
7.4 Tip vortex=strut interaction
7.5 Model testing
7.6 Model=ship extrapolation
7.7 Problems
7.8 Solutions (numerical problems)
7.9 References
Chapter 8 Propellers in ice
8.1 Loading on a propeller blade in ice
8.2 Traditional propeller ice strength prediction
8.3 Strength prediction
8.4 Exceptional Load Limit State
8.4.1 Interaction between loading limit states on an ice class propeller
8.5 Implementation of the design interaction equation for initial design
8.6 Numerical prediction of loads in ice
8.7 Problems
8.8 Solutions (numerical problems)
8.9 References
Chapter 9 Cycloidal propellers
9.1 Performance prediction methods
9.2 Multiple streamtube theory
9.2.1 Power absorbed, thrust and other resolved forces developed by the propeller
9.2.2 Propeller coefficients
9.3 Foil section data
9.4 Extensions and refinements
9.5 Problems
9.6 Solutions (numerical problems)
9.7 References
Chapter 10 Waterjets
10.1 Powering prediction
10.2 Initial design
10.2.1 Effect of simplifying assumptions on the analysis method
10.3 Outline design example
10.4 Problems
10.5 Solutions (numerical examples)
10.6 References
Chapter 11 Oscillating propulsors
11.1 How an oscillating foil generates thrust
11.2 Overview of some numerical studies
11.3 A comparison of potential propulsor designs
11.4 Design charts
11.5 Wave propulsion using oscillating propulsors
11.6 Problems
11.7 Solutions (numerical problems)
11.8 References
Chapter 12 Wind assisted ship propulsion
12.1 Types of wind assisted propulsion devices
IV MARINE POWERING PREDICATION AND PROPULSOR PREDICTION
12.1.1 Soft sails
12.1.2 Rigid airfoils
12.1.3 Mechanically assisted high lift devices
12.1.4 Wind turbines
12.1.5 Kites
12.2 Performance envelopes of different devices
12.3 Assessment of fuel savings possible with a wind assisted rig
12.4 Example – Flettner rotor ship
12.5 Problems
12.6 Solutions (numerical problems)
12.7 References
Appendix A: An implementation of Grigson’s friction line
Grigson’s friction line
Comparison between different friction lines
References
Appendix B: Program for trochoidal propeller performance
Input data file
Example of output data file
References
Appendix C: Wind assisted ship propulsion program
Appendix D: Vessels mentioned in text
Index
Author=Name Index
TABLE OF CONTENTS V

Table of Figures
Figure 2-1 Plot showing an approach to obtain the self-propulsion point
Figure 2-2 Method to obtain the wake fraction – thrust identity
Figure 2-3 Correction in open water values of thrust (top) and torque (bottom) coefficients
for variation in frictional drag over the propeller blades between model and full scale
Figure 2-4 Method to find the operating point of the ship propeller
Figure 3-1 Towing force plotted against propeller thrust for Canadian R-Class icebreaker tests.
Figure 3-2 Adjustment of thrust coefficient in the behind condition for wake scaling
Figure 3-3 Example of method to find the advance coefficient of the propeller at the propeller
operating point of the ship
Figure 3-4 Plot showing method to obtain the form factor – the intercept of the regression line
on the y-axis is the value of 1þk
Figure 3-5 R-Class icebreaker – predicted propeller revolutions plotted alongside full scale
trials values
Figure 3-6 R-Class icebreaker – predicted propeller torque plotted alongside full scale
trials values
Figure 3-7 R-Class icebreaker – extrapolated delivered power plotted alongside full scale
trials values
Figure 4-1 Uncertainty in ship power prediction in an extrapolation using the ITTC 1
method when a 1% uncertainty (standard deviation) is assumed in inputs from all model tests
(Molloy et al. 2006).
Figure 4-2 Uncertainty in ship delivered power resulting from uncertainty in the turbulent
flat plate friction line or ship model correlation line (ITTC 1978 extrapolation)
(Molloy et al. 2006).
Figure 4-3 Uncertainty in ship delivered power resulting from uncertainty in the form
factor (standard deviation 10%; ITTC 1978 extrapolation) (Molloy et al. 2006).
Figure 4-4 Uncertainty in ship delivered power resulting from uncertainty in the
wake fraction (standard deviation 10%; ITTC 1978 extrapolation) (Molloy et al. 2006).
Figure 4-5 Uncertainty in ship delivered power resulting from uncertainty in the
correlation allowance (standard deviation 50%; ITTC 1978 extrapolation)
(Molloy et al. 2006).
Figure 4-6 Uncertainty in ship delivered power: comparison of extrapolations done
using the ITTC 1978 method and using load varied, self-propulsion tests only
(uncertainty in all test inputs, friction line, wake scaling, thrust deduction fraction
and form factor) (Molloy 2006).
Figure 5-1 Action of an accelerating nozzle
Figure 5-2 Nozzle shapes of NSMB=MARIN ducts 19A and 37 (Gent and Oosterveld 1983).
The leading and trailing edge radii are given as percentages of chord length.
Figure 5-3 Performance curves for ducted propeller Ka 3.65 in nozzle 19A plotted using
the regression polynomials for this propeller. The solid lines are total thrust coefficient
for a P=D ratio from 0.6 (lowest curve) to 1.4 (highest curve) in 0.2 increments;
the dotted lines are torque coefficient from 0.6 (lowest curve) to 1.4 (highest curve);
the dashed lines are the nozzle thrust coefficient from 0.6 (lowest curve) to 1.4 (highest curve);
and the chain dotted lines are open water efficiency from 0.6 (left hand curve)
to 1.4 (right hand curve).
Figure 5-4 Performance chart of B-Series propeller B4.70 at a pitch=diameter ratio of 0.8;
plotted using the B-Series polynomials (e.g. Manen and Oossanen 1988).
Figure 5-5 Performance curves for ducted propeller Ka 4.70 in nozzle 19A plotted
using the regression polynomials for this propeller. The solid lines are total thrust coefficient
for a P=D ratio from 0.6 (lowest curve) to 1.4 (highest curve) in 0.2 increments;
the dotted lines are torque coefficient from 0.6 (lowest curve) to 1.4 (highest curve);
the dashed lines are the nozzle thrust coefficient from 0.6 (lowest curve) to 1.4 (highest curve);
and the chain dotted lines are open water efficiency from 0.6 (left hand curve)
to 1.4 (right hand curve). The double chain dotted line is the curve KQ1:61J 5 (see text).
Figure 5-6 Thrust, net thrust and vessel resistance for the example towing vessel
for both open and ducted propellers.
Figure 5-7 Power and revolutions for the example towing vessel for both open
and ducted propellers.
Figure 5-8 Torque for the example towing vessel for both open and ducted propellers.
Figure 5-9 Typical diesel engine characteristic curve.
Figure 5-10 Propeller performance overlaid on engine characteristic curve.
Figure 5-11 Simplified chart of performance of controllable pitch propeller 4
at a design pitch=diameter ratio of 1.0. Thrust and torque coefficients are shown for
pitch=diameter settings of 1.0 and 1.1 (Kuiper 1992).
Figure 5-12 Model cyclic pitch propeller with raked back blades: top image showing
profile of mechanism including swash plate and actuators; lower image showing the
blade assembly (reproduced with permission from Charles Humphrey – Humphrey 2005).
Figure 6-1 Diagrammatic example of surface piercing propeller configuration
Figure 6-2 Typical trend of thrust coefficient with loading for a surface piercing
propeller – the numbers represent the regions that are described in the text
Figure 6-3 Immersion of a surface piercing propeller
Figure 6-4 Regression to data of critical advance coefficient for the L4.68 propeller
series (symbols designate line type only, not data)
Figure 6-5 Nominal immersion area of propeller – A0 is the area of the propeller disc
below the water surface
Figure 6-6 Plot showing linear regression lines to data (symbols designate
line type only, not data; numbers in legend denote P=D ratio)
Figure 6-7 Plot showing second order regression lines to data (symbols designate
line type only, not data; numbers in legend denote P=D ratio)
Figure 7-1 Sketch of typical tractor=puller pod showing offset angle in the vertical
plane for alignment with the local flow.
Figure 7-2 A model counter-rotating Azipod system from ABB Industry Oy
(Copyright ABB Australia Pty Limited – reproduced with permission).
Figure 7-3 A 1990 Azipod (Azimuthing Podded Drive) from ABB Industry Oy.
The system has a motor inside a submerged pod that is 3608 steerable
(Copyright ABB Australia Pty Limited – reproduced with permission).
Figure 7-4 Sketch of plan view of a pair of tractor pods showing exaggerated
offset in the horizontal plane (in this case ‘‘tow out’’).
Figure 7-5 Sketch showing puller=tractor (top left), pusher pods (top right) and
designs with two co- or contrarotating propellers (lower). Arrows show flow direction.
Figure 7-6 Geometric parameters were used to characterise pod series designs
(Molloy et al. 2005; Molloy 2006; Islam et al. 2006c).
Figure 7-7 The 16 pods used in the geometric series tests (Molloy et al. 2005;
Molloy 2006; Islam et al. 2006c).
Figure 7-8 Example of a podded propeller test boat and dynamometer
(MacNeill et al. 2004; Islam et al. 2006c).
Figure 8-1 Model ice-class propeller of the Canadian R-Class icebreaker (Searle et al. 1999a).
VIII MARINE POWERING PREDICATION AND PROPULSOR PREDICTION
Figure 8-2 Highly skewed model ice-class propeller of a type used on the
Canadian east coast ferry Caribou (Searle et al. 1999a and b).
Figure 8-3 Damage to the blade tips of a highly skewed ice-class propeller: a. model;
b. full scale (Searle et al. 1999b).
Figure 8-4 Schematic of a propeller blade milling ice showing pulverized ice particles
on the back and spalling of ice flakes on the blade face.
Figure 8-5 Direction of resultant ice contact force (Searle et al. 1999a, figure 15).
Figure 8-6 Thrust coefficient (upper) and torque coefficient (lower) for the ice class
propeller model shown in Figure 8-1 at a depth of cut=diameter ratio of 0.18 and an
ice compressive strength (model) of 170 kPa (Searle et al. 1999a). The open circles and
triangles show maximum and minimum values; the solid symbols are the mean values;
the lines without symbols are the open water coefficients for this propeller.
Figure 8-7 Definition of cut depth (Searle et al. 1999a).
Figure 8-8 Blade thrust on a highly skewed propeller milling ice over two revolutions
measured using an in-hub blade dynamometer (forwards thrust is shown as negative in this plot)
(Moores et al. 2002). The horizontal dashed line is the open water load at a similar condition.
Figure 8-9 Blade root thicknesses predicted using the exceptional load limit state and
compared with existing blade root thicknesses for several ice-class vessels – all vessels
have the same exposure represented by an expected number of interaction events per
year of 10.
Figure 8-10 Blade root thicknesses predicted using the exceptional load limit state and
compared with existing blade root thicknesses for several ice-class vessels – vessels with
controllable pitch propellers have a reduced exposure represented by an expected number of
interaction events per year of 1.
Figure 8-11 Comparison of thrust and torque coefficients between a numerical simulation
and tests of a 0.3m diameter model propeller milling ice to a depth of 15mm in an ice tank
(Wang et al. 2006).
Figure 9-1 Propeller geometry showing blade angles for trochoidal blade motion
(Veitch 1990).
Figure 9-2 Orbital paths of cycloidal propellers (Veitch 1990).
Figure 9-3 Thrust and torque coefficients for a trochoidal propeller. Experimental data at
150 and 200 rpm are shown by the circles and crosses respectively. Lines show the predictions.
The key to the predictions is shown in the above table (Riijarvi et al. 1994; Li 1991).
Figure 9-4 Flow through propeller and elemental streamtube (Bose 1987).
Figure 9-5 Velocities, forces and inflow angles at a blade element. The position O is the
axis of the propeller.
Figure 10-1 Normalized energy flux levels and definition of station numbers in the
momentum flux method. Station definitions are given in Table 10-1.
Figure 10-2 Variation of propulsive efficiency with jet velocity ratio, VJ =V. The lines
are drawn for a pump element efficiency, hP, of 0.85 and for varied intake efficiency,
the values of which are shown in the legend.
Figure 10-3 Variation of the propulsive efficiency with different losses in a waterjet.
The curve for an intake efficiency of 0.6 is the same as that shown in Figure 10-2 and
the additional losses are drawn relative to this curve.
Figure 11-1 Approximate shapes of fluke planforms. (The key to the abbreviations
is as follows: hp2, harbour porpoise 2; wsd, white-sided dolphin; sbw, Sowerby’s
beaked whale; mw, minke whale; hp1, harbour propoise 1; wbd, white-beaked dolphin;
fw, fin whale; sw, sperm whale; cd, common dolphin; ww, white whale) (Bose et al. 1990).
Figure 11-2 Approximate shapes of one fluke section from each specimen,
(for key see Figure 11-1) (Bose et al. 1990).
Figure 11-3 The planform shape of a white-sided dolphin (left) and an immature fin
whale (right).
TABLE OF FIGURES IX
Figure 11-4 Overall view of a white-sided dolphin
Figure 11-5 A machined model of a fin whales flukes
Figure 11-6 Sectional view of an immature fin whales’s fluke displaying spanwise flexibility,
in this case induced by a weighted piece of string
Figure 11-7 An oscillating propeller model showing the fin (right) and the strut (left).
In use, the lower part of the strut fits into the holes in the fin; it can be held in position
with PVC tape.
Figure 11-8 The rigid (chain dotted) and flexible section shapes on the downstroke
(upper) and upstroke for a foil oscillating at a reduced frequency of 0.2 and a feathering
parameter of 0.4. The rear half of the foil is flexible; amplitude of the trailing edge
deflection is 0.1 of the chord length (Bose 1995).
Figure 11-9 Sketch of ship and oscillating foil propeller (Yamaguchi & Bose 1994).
Figure 11-10 Quasi propulsive efficiency of flexible and rigid oscillating propulsors
and a MAU 5-55 conventional screw propeller against ship speed in knots
(1 knot ¼0.5144 ms 1). Values shown without a sea margin are shown by dotted lines;
values including a 15% sea margin on power are shown by the solid lines.
Open water and quasi propulsive efficiencies are the same for the oscillating propulsors.
Figure 11-11 Open water efficiency against propeller load ratio. The dotted line is
the ideal efficiency from propeller momentum theory; the solid line is for the MAU 5-
conventional screw propeller; * is for the flexible foil with no friction losses (losses are due to
wasted lateral water motion), þ is for the same propulsor with friction losses; 8 is for the rigid
foil with no friction losses and is for the same propulsor with friction losses. The . marks
the design point for each propulsor.
Figure 11-12 Thrust coefficient (dashed lines) and efficiency (solid lines) contours
for a 2D oscillating propulsor plotted for a range of phase angles and advance ratio.
A phase of 908 means that, for a horizontal foil, a maximum nose down pitch occurs at
zero heave amplitude on the downstroke (Bose 1995).
Figure 11-13 Variation of thrust coefficient with change in motion parameters (Bose 1995).
Figure 11-14 Variation of propulsive efficiency with changes in motion parameters
(Bose 1995)
Figure 11-15 Diagrammatic representation of a wave propulsion device.
Figure 12-1 Fishing craft, Gopalpur, India, with soft sail rigs made from plastic
tarpaulin material. Millions of commercial sailing craft, of which these are just one example,
operate throughout the world every day and are important to the economy.
Figure 12-2 The Senyo Maru, looking forward from the bridge at the furled wingsail unit
on the bow.
Figure 12-3 Furled wingsail unit above the bridge of the Senyo Maru.
Figure 12-4 View of rear of wing sail unit with sail open.
Figure 12-5 Wingsail unit showing furling mechanism.
Figure 12-6 Wingsail unit showing yawing=trimming mechanism.
Figure 12-7 Wingsail unit showing wing face and fabric panels.
Figure 12-8 Modes of operation of a wind turbine rig: in autogyro mode (upper),
and windmill mode (lower).
Figure 12-9 Falcon on the Firth of Clyde in 1985
Figure 12-10 Jim Wilkinson’s Revelation on the Crouch, England, 1984.
Figure 12-11 Rob Denney’s wind turbine Iroquois catamaran.
Figure 12-12 Brad Blackford’s wind turbine boat, Nova Scotia, Canada, 2007.
The picture shows the boat from the stern. The boat travels at speeds up to just over half
of windspeed. (Photo credit: Roy L. Bishop).
Figure 12-13 Forces acting and relative velocity triangle for a wind turbine boat operating
in the windmill mode (Note that the vessel speed referred to as VS in the text
is shown as Vb in the figure).
X MARINE POWERING PREDICATION AND PROPULSOR PREDICTION
Figure 12-14 Aerial view of the M.S. Beaufort (Copyright SkySails-reproduced
with permission).
Figure 12-15 Kite rig on the M.S. Beluga Skysails (Copyright SkySails-reproduced
with permission).
Figure 12-16 Forces acting and relative velocity triangle.
Figure A- 1 Flow chart of algorithm.
Figure A- 2 Wake strength parameter as a function of momentum thickness Reynolds number.
The data points are from profiles fitted to measurements of Smith and Walker,
Wieghardt and Karlsson (Grigson 1999).
Figure A-3 Plot of Grigson’s friction lines, Schlicting’s line and the ITTC 1957 model
ship correlation line.
Figure A-4 Ratio of Grigson’s lines to the ITTC 1957 line.
TABLE OF FIGURES XI

List of Tables
Table 1-1 Types of marine propulsors
Table 4-1 Test parameters varied in the uncertainty analysis study for which results are
shown in Figure 4-1.
Table 5-1 Profile offsets of NSMB=MARIN ducts 19A and 37 (Gent and Oosterveld 1983).
Table 5-2 Performance of existing open propeller
Table 5-3 Values from the K-J chart for a Ka 4.70 propeller in nozzle 19A corresponding to
values of KQ1:61J 5 (see Figure 5-5). Checked and supplemented by the code PSP
(Kuiper 1992).
Table 5-4 Values from the K-J chart for a B4.70 propeller corresponding to values of KQ1:61J 5.
Checked and supplemented by the code PSP (Kuiper 1992).
Table 5-5 Performance of the ducted propeller.
Table 5-6 Performance results for a controllable pitch propeller design.
Table 7-1 Extremes of ratios of pod dimensions seen in service (Molloy et al. 2004;
Molloy et al. 2005; Molloy 2006; Islam et al. 2006c).
Table 8-1 Approximate as built=designed particulars for some ice class vessels and
their propellers.
Table 8-2 Estimated extreme blade loads for some ice class propellers (Bose et al. 1998).
Table 10-1 Definition of stations for points through a waterjet.
Table 10-2 Summary of input and estimated parameters from waterjet example.
Table 12-1 Wind assisted propulsion performance envelope chart (modified from WASP 1982).
Key: A – rigid aerofoil; K – kite; M – mechanically assisted high lift device; S – soft sail;
W – wind turbine; VS=VW - ship speed=true wind speed ratio; a – true wind heading angle.
Table 12-2 Wind speed and direction data over a 15 year period for an exposed coastal station
on the Firth of Clyde in Scotland. The data is based on hourly averages. The numbers are
percentages of mean wind direction and speed. The height of the instrument above (mean)
sea level is 24 m; and above ground is 20 m. The heading angles are 30 degree bins.
The figure 0.00 is less than 0.005 and the figure 0.0 is 0.
Table 12-3 Driving and heeling force coefficients of a Flettner rotor rig from wind tunnel tests
(Williams and Liljeberg 1983).
Table 12-4 True wind heading angles corresponding to the true wind directions for the
Flettner rotor assisted ferry on outward and return courses.
Table 12-5 Results of wind speed=vessel speed ratio, apparent wind heading angle and
apparent wind speed for a vessel speed of 7 knots (3.6 ms 1) and a true wind heading
angle of 708.
Table A-1 Tabulated values of the ratio of Grigson’s friction line to the ITTC 1957 line
(using Grigson’s direct method).
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