2.2. Selection of Wave Cases

A large number of wave cases may be selected in the AqwaWave data. This is achieved by defining a wave frequency number and a wave direction number from the preceding Aqwa-Line data and then specifying a wave height and phase to be associated with them. The wave height is required since the Aqwa-Line run is for unit wave amplitude and must be scaled to the required height. The phase is necessary as the drag forces that can be produced by the program generally do not vary sinusoidally and cannot be represented dynamically as in Aqwa-Line.

Pressures from the Aqwa-Line analysis are then extracted from the hydrodynamic database files and evaluated for the selected height/phase as follows:

Where:

Pθ = the pressure at the required phase

H/2 = the required wave amplitude (H is the wave height)

Pr, Pi = real and imaginary components of pressure from Aqwa-Line

θ = the required phase

Optionally, static pressures may be calculated and added to the above time varying pressures by the setting of the ‘STAT’ option in the AqwaWave data. The revised pressure is then simply given as:

Where:

Ps = hydrostatic pressure

Static pressure alone can be obtained by setting the STAT option and specifying a zero wave height. Load cases created by AqwaWave will be sequenced from 1001 unless you specify a different load case offset (see LCOF command in Load Case Data - LOAD).