# Terminology¶

Term | Definition |
---|---|

Added Mass | |

BEM | Boundary Element Method |

BEMIO | Boundary Element Method Input/Output |

BS | Bretschneider Wave Spectrum |

`$CASE` |
WEC-Sim case directory |

Heave (Z) | Motion along the Z-axis |

JS | JONSWAP Spectrum |

Pitch (Ry) | Rotation about the Y-axis |

PM | Pierson-Moskowitz Specturm |

PTO | Power Take-Off |

Radiation Damping | |

Roll (Rx) | Rotation about the X-axis |

`$SOURCE` |
WEC-Sim source code directory |

Surge(x) | Motion along the X-axis |

Sway (Y) | Motion along the Y-axis |

Wave Excitation | |

Yaw (Rz) | Rotation about the Z-axis |

## Variables¶

Variable | Definition |
---|---|

* | Wave amplitude (m), |

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 take-off 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) | |

* | Energy period (s) |

Peak period (s) | |

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

Note

This section is a work in progress, * means may not be used in WEC-Sim doc