AAU |
Aalborg University |
API |
American Petroleum Institute |
CFD |
Computational Fluid Dynamics |
CoE |
Cost of Energy |
COG |
Centre of Gravity |
DNV |
Det Norske Veritas |
DOF |
Degree of Freedom |
FOWT |
Floating Offshore Wind Turbine |
FEED |
Front End Engineering Design |
GOM |
Gulf of Mexico |
IRF |
Impulse response Function |
IFFT |
Inverse Fast Fourier Transform |
kV |
Kilovolt |
MW |
Megawatt |
MWh |
Megawatt hour |
NREL |
National Renewable Energy Laboratory |
OWT |
Offshore Wind Turbine |
POA |
Point of Attack |
QTF |
Quadratic Transfer Function |
RAO |
Response Amplitude Operator |
RNA |
Rotor Nacelle Assembly |
TB |
Tower Bottom |
TLP |
Tension Leg Platform |
TM |
Top Mass |
TWh |
Terawatt hours |
ULS |
Ultimate Limit State |
Greek Symbols |
|
γ |
Spectral peak enhancement Factor |
|
Structural damping values for the first and second eigenmode |
η |
Wave elevation |
|
Radiation Damping Force vector at COG |
μ |
Transformed Radiation Damping Force vector at Point of Interest |
A |
Projected Area |
Ai or Aj |
Amplitude of the sinusoidal regular wave |
A,B,C,D |
State Space Matrices |
Ca |
Added Mass Coefficient |
cD |
Drag Coefficient |
CTopside |
Structural Damping Matrix of the Topside |
|
Impulse Response Function of the Radiation Damping |
Fexc(t) |
1st order wave excitation Force in time domain from summation of sinusoidal components |
|
1st order wave excitation Force in time domain from the convolution of non-causal IRF with |
Fexc(ωt) |
1st order wave excitation force coefficient in the frequency domain |
|
2nd order wave excitation Force in time domain from summation of sinusoidal components |
|
Complex sum frequency dependent 2nd order wave excitation coefficients |
|
2nd order wave excitation Force in time domain from summation of sinusoidal components |
|
Complex different frequency dependent 2nd order wave excitation coefficients |
FMooring |
Mooring Force Vector |
FExc_inertial |
Excitation Force vector due to Diffraction Force and Froude-Krylov Force |
FExc_viscous drag |
Excitation Force vector due to hydrodynamic viscous Drag |
g |
Acceleration of Gravity |
H(rCOG) |
Transformation matrix from centre of gravity to point of interest |
|
Excitation force unit impulse response functions |
Hmax |
Design Wave Height |
Hm0 |
Spectral significant wave height |
Hs |
Statistical significant wave height, generally assumed equal to Hm0 |
ki |
wave number |
kTopside |
Structural Stiffness Matrix of the Topside |
|
Hydrostatic Stiffness matrix of the Floater at COG |
kFloater |
Transformed hydrostatic Stiffness matrix of the Floater at Point of Interest |
l |
Length of the Tower |
|
Mass matrix of the Floater at COG |
MFloater |
Transformed Mass matrix of the Floater at Point of Interest |
MTopside |
Mass Matrix of the Topside |
MTower |
Mass matrix of the Tower |
|
Hydrodynamic added Mass matrix of the Floater at COG |
ρ |
Density |
φi |
Random phase |
ωi |
Wave frequency of the ith Wave |
ω1 & ω2 |
1st and 2nd structural eigenfrequencies of the topside |
mhFloater |
Transformed Hydrodynamic added Mass matrix of the Floater at Point of Interest |
TDesign |
Period of Design Wave |
Tp |
Peak Wave Period |
rCOG |
Vector from COG to Point of Interest |
SF30 |
30th order Stream-function Wave |
u |
water particle velocity |
v |
small body of mass velocity |
V |
small body Volume |
x |
Displacement |