The environment slave will provide at least the Hull slave and the Propulsion slave with information about the current environment. This includes information about waves, wind and current.

The wind can be defined by:

  • Wind speed (m/s)
  • Wind direction (global, relative to north (coming FROM))
  • Reference height (typically reference wind speed is for 10 m height above sea level)

The waves can be defined by all or a subset of:

  • Wave spectrum
  • Significant wave height
  • Spectral peak period
  • Principal wave direction (global, relative to north (coming FROM))

(possibly also separate swell)

  • Wave spreading relative to principal wave direction
  • Wave Fourier components (amplitude, phase, direction) (actually, these are probably all that is needed by the other modules)
  • Spectrum type (ITTC, JONSWAP, Doubly Peaked, …)
  • Significant wave height in sea state
  • Peak frequency component in sea state
  • Mean direction of sea state
  • Spreading factor for direction spectrum
  • Gamma value for JONSWAP spectrum
  • Number of waves
  • Number of frequency components in simulation
  • Number of wave directions in simulation
  • Cutoff frequency for spectrum
  • Cutoff direction for spectrum

The current can be defined by (assuming uniform current):

  • Current velocity
  • Current direction (global, relative to north (going TO))
  1. Calculate the environment in one slave, instead of calculating it in every slave that needs the wave forces