stability of floating bodies
ME2134-1 STABILITY OF FLOATING BODY
(WS2-01-47)
SEMESTER 3
2014/2015
NATIONAL UNIVERSITY OF SINGAPORE
DEPARTMENT OF MECHANICAL ENGINEERING
CONTENTS
TABLE OF CONTENTS i
LIST OF ILLUSTRATIONS i
LIST OF SYMBOLS ii
INTRODUCTION 1
THEORY OF OPERATION 1
DESCRIPTION OF EQUIPMENT 5
EXPERIMENTAL PROCEDURE 6
ANALYSIS AND DISCUSSION 8
REFERENCES 9
LIST OF ILLUSTRATIONS
Figure 1 Static stability of a floating body. 2
Figure 2 Inclined experiment to determine GM and KG. 3
Figure 3 Illustration depicting plane of flotation. 4
Figure 4 Effects of free surface. 5
Figure 5 Ballasting of 20 compartments of barge with water (top view). 7
LIST OF SYMBOLS
B Center of buoyancy
B’ Displaced center of buoyancy
d Transverse distance of displacement of added mass
FB Buoyancy force or upthrust
G Center of gravity of floating body
G’ Displaced center of gravity of floating body
G1 Displaced center of gravity of floating body with free surface
GZ Moment arm of restoring couple
g Acceleration due to gravity
IOy Second moment of area of plane of floatation about its longitudinal axis
i Second moment of area for free surface tank
K Keel
KOy Mass radius of gyration of floating body about its longitudinal axis
M Transverse metacenter
m Mass
T Period of oscillation
W Weight of floating body
Greek Symbols:
Angle of heel or inclination
Density of seawater
f Density of liquid in tank
INTRODUCTION
Stability is a measure of the tendency of an ocean vehicle to return to its upright configuration if inclined or perturbed by an external force (Figure 1). For different operating conditions, stability can be classified into the following categories: Intact stability (static stability and dynamic stability) and damage stability. It is imperative to ascertain the overall stability
(WS2-01-47)
SEMESTER 3
2014/2015
NATIONAL UNIVERSITY OF SINGAPORE
DEPARTMENT OF MECHANICAL ENGINEERING
CONTENTS
TABLE OF CONTENTS i
LIST OF ILLUSTRATIONS i
LIST OF SYMBOLS ii
INTRODUCTION 1
THEORY OF OPERATION 1
DESCRIPTION OF EQUIPMENT 5
EXPERIMENTAL PROCEDURE 6
ANALYSIS AND DISCUSSION 8
REFERENCES 9
LIST OF ILLUSTRATIONS
Figure 1 Static stability of a floating body. 2
Figure 2 Inclined experiment to determine GM and KG. 3
Figure 3 Illustration depicting plane of flotation. 4
Figure 4 Effects of free surface. 5
Figure 5 Ballasting of 20 compartments of barge with water (top view). 7
LIST OF SYMBOLS
B Center of buoyancy
B’ Displaced center of buoyancy
d Transverse distance of displacement of added mass
FB Buoyancy force or upthrust
G Center of gravity of floating body
G’ Displaced center of gravity of floating body
G1 Displaced center of gravity of floating body with free surface
GZ Moment arm of restoring couple
g Acceleration due to gravity
IOy Second moment of area of plane of floatation about its longitudinal axis
i Second moment of area for free surface tank
K Keel
KOy Mass radius of gyration of floating body about its longitudinal axis
M Transverse metacenter
m Mass
T Period of oscillation
W Weight of floating body
Greek Symbols:
Angle of heel or inclination
Density of seawater
f Density of liquid in tank
INTRODUCTION
Stability is a measure of the tendency of an ocean vehicle to return to its upright configuration if inclined or perturbed by an external force (Figure 1). For different operating conditions, stability can be classified into the following categories: Intact stability (static stability and dynamic stability) and damage stability. It is imperative to ascertain the overall stability
References: Comstock J. P., “Principles of Naval Architecture”, Society of Naval Architects and Marine Engineers, 1967. Muckle W., “Naval Architecture for Marine Engineers”, Newnes-Butterworths, 1975. Rawson K. J. and Tupper E. C., “Basic Ship Theory”, Longman, 4th Edition, 1994. Teo C. J., Lecture notes for ME2134: Fluid Mechanics I. Stokoe E. A., “Reed 's naval architecture for marine engineers”, Thomas Reed, 4th Edition, 1991. Tupper E. C., “Introduction to Naval Architecture”, Butterworth Heinemann, 4th Edition, 2004.