Course Program

Introduction to Ocean Energy AAF1776- 3 CFU

The oceans have huge potential as sources of renewable energy. Several technologies are under development to harness that energy to power human activity. These technologies are tidal stream, wave, Ocean Thermal Energy Conversion (OTEC), salinity gradient and tidal range.

Course goal is to provide the participants with the basic design methodology to evaluate the performance of the ocean energy devices:

Energy from the Ocean (why, how)

Ocean Resource Potential ( Wave, tidal range, tidal currents, ocean currents, thermal energy, OTEC, Salinity gradients)

Waves

• Basic definitions

• Classification of sea waves

• Capillary waves

• Surface gravity waves

• Wind generated waves

• Stokes drift

• Wave classification based on water depth

• Wave interaction with seafloor

• Breaking wave classification

• Derivation of the governing equations

• Linear gravity waves

• Linear Gravity Waves- Analytical solution

• Wave group velocity

• Phase and group velocity for water waves

• Effects of wave dispersion

• Reflection, diffraction

• Energy of linear waves

• Energy flux of linear waves

• Limitation of linear waves theory

• Non linear waves theories (outline)

• Random waves

• Analysis of ocean waves and sea state data (fourier representation, spectral analysis, significant wave height, spectrum moments)

• Energy flux of random sea

Wave energy Converters

• Classification

• Wave energy conversion steps

• Devices (Point absorbers, Attenuators, Terminators, Oscillating water column, Overtopping )

• Modelling of WEC

• WEC dynamics

• Energy storage

• PTO Systems

• PTO Equipment (linear electric generator, Hydraulic turbines, high pressure oil PTO, air turbines)

• Mooring systems (outline)

Tidal energy Converters

• Classifications

• Vertical and horizontal axis turbines

• Principles of Current Energy Conversion

• Betz’s Elementary Momentum Theory

• Drag type tidal turbines

• Blade Element Theory

• Performance of wing foils

• Foil sections for horizontal axis turbines

• Performance characteristics of HATT

• Typical problems of HATT (cavitation, ventilation, fouling)

• Comparison between tidal and wind turbine

Model testing of Ocean energy devices