Terminology¶
Term 
Definition 

Added Mass 

BEM 
Boundary Element Method 
BEMIO 
Boundary Element Method Input/Output 
BS 
Bretschneider Wave Spectrum 

WECSim case directory 
Heave (Z) 
Motion along the Zaxis 
JS 
JONSWAP Spectrum 
Pitch (Ry) 
Rotation about the Yaxis 
PM 
PiersonMoskowitz Specturm 
PTO 
Power TakeOff 
Radiation Damping 

Roll (Rx) 
Rotation about the Xaxis 

WECSim source code directory 
Surge(x) 
Motion along the Xaxis 
Sway (Y) 
Motion along the Yaxis 
Wave Excitation 

Yaw (Rz) 
Rotation about the Zaxis 
Variables¶
Variable 
Definition 

Frequency dependent radiation added mass (kg) 

Added mass at infinite frequency (kg) 

Frequency dependent radiation wave damping (N/m/s) 

Morison element coefficient of added mass 

Quadratic drag coefficient 

Mooring damping matrix (N/m/s) 

PTO damping coefficient (N/m/s) 

Linear (viscous) damping coefficient (N/m/s) 

Incident wave (m) 

Wave frequency (Hz) 

Net buoyancy restoring force (N) or torque (N.m) 

Wave excitation force (N) or torque (N.m) 

Wave radiation force (N) or torque (N.m) 

Power takeoff force (N) or torque (N.m) 

Morison element force (N) or torque (N.m) 

Damping or friction force (N) or torque (N.m) 

Mooring connection force (N) or torque (N.m) 

Gravity (m/s/s) 

Water depth (m) 

Wave height (m) 

Significant wave height, mean wave height of the tallest third of waves (m) 

Spectrally derived significant wave height (m) 

Wave number (rad/m), 

Linear hydrostatic restoring coefficient (N/m) 

Mooring stiffness matrix (N/m) 

PTO stiffness coefficient (N/m) 

Wave length (m) 

Mass of body (kg) 

Spectral moment of k, for k = 0,1,2,… 

Wave frequency (rad/s), 

Wave phase (rad) 

Ramp function 

Water density (kg/m3) 

Simulation time (s) 

Ramp time (s) 

Wave direction (Degrees) 

Peak period (s) 

Translation and rotation displacement vector (m) or (rad) 