a
variable in spectrum definition
variable in spectrum definition, non-dimensional damping factor
g
peak enhancement factor
e
phase
z
wave elevation
z0
wave amplitude
z1/3
significant wave amplitude
q
angular motion
l
wave length
m
wave heading relative to vessel
r
water density
displaced volume of vessel
s
spectral width parameter
s0
standard deviation of wave spectrum (RMS)
w
wave frequency
we
encounter frequency
A
variable in spectrum definition
a
added mass, linear acceleration
B
vessel beam, variable in spectrum definition
b
Damping
c
wave speed, restoring force (stiffness)
Caw
added resistance coefficient in regular waves
E
Energy
F
excitation force
g
acceleration due to gravity
H
wave height
H1/3
significant wave height
Hchar
Characteristic wave height
kxx
roll radius of gyration
kyy
pitch radius of gyration
I
Inertia
L
length of vessel
m
Mass
m0
variance of wave spectrum, zeroth spectral moment
mn
nth spectral moment
p
Probability
q
Probability
Raw
added resistance in regular waves
total added resistance in irregular waves
RAO
response amplitude operator
S
spectral energy
T
wave period
T0
modal wave period
Tave
average wave period
Tz
zero-crossing wave period
t
Time
tf
transfer function (RAO)
Uwind
wind speed
U
ship speed
u*
threshold velocity
z
linear motion