Page 243 - Fundamentals of Ocean Renewable Energy Generating Electricity From The Sea

232 Fundamentals of Ocean Renewable Energy

FIG. 8.27 Time series of simulated turbulent kinetic energy in January 2000 at three contrasting
sites: site 2 (ebb-dominant), site 9 (almost symmetrical), and site 21 (flood-dominant). The lower
panel shows a time series of TKE at the model cell closest to the bed. For reference, vertical dashed
lines are located at peak flood and ebb conditions for site 9.

time series manifests itself as a strong asymmetry in TKE (Fig. 8.27). The
production of turbulent kinetic energy is generally proportional to the magnitude

2

2
of the velocity gradient P ∝ ∂U + ∂V . For a specific velocity
∂z ∂z
distribution (e.g. a logarithmic distribution), this gradient will be proportional
to the current strength. Therefore, we expect magnified turbulence asymmetry
due to asymmetry in the current strength.