Page 233 - Fundamentals of Ocean Renewable Energy Generating Electricity From The Sea

222 Fundamentals of Ocean Renewable Energy

FIG. 8.17 Galway Bay and surrounding region showing the boundary of the inner nested model
domain. The asterisk shows the location of the wave time series used for model validation. Contours
are water depth in metres, relative to MSL.

The model was nested inside a coarser outer SWAN model which covered
the North Atlantic at a grid resolution of 1/12 × 1/12 degrees. The outer model
was used to output 2D wave spectra hourly at the boundary grid locations of the
inner nested model domain. Both models were forced with ERA-Interim wind
fields, available 3-h at a grid resolution of 0.75 × 0.75 degrees. There was no
feedback from the inner to outer nest, that is, the nesting process was one-way—
this is common practice in wave modelling studies.
The spatial resolution of the inner nested model was 1/400 × 1/400 degrees
(approximately 270 m), and the directional resolution was set to 12 degrees.
Forty discrete frequency intervals were simulated over the range 0.04–4.0 Hz
(i.e. 0.25–25 s), and these were distributed logarithmically, leading to increased
resolution at lower frequencies (Fig. 8.18).