Descriptif

Sea States, Wave Propagation, and Ocean Wave Energy

The proposed course is divided in three main parts: (1) Characterizing waves and describing the
important physical processes governing oceanic and nearshore wave propagation, (2) Numerical
modeling of wave propagation, and (3) Ocean wave energy, including wave-structure interactions.

At the end of the course, a student should be able to:
- describe wave characteristics using deterministic and spectral approaches,
- understand the dierent physical processes governing wave transformation at a range of spatial
and temporal scales, from wind generation to interactions with the bottom,
- evaluate the appropriate numerical modeling approaches to use for dierent applications,
- understand the physical processes governing wave-body interactions,
- estimate the absorbed wave energy of a wave energy converter, and
- evaluate the application of industrial and academic numerical modeling approaches to simulate
wave-structure interactions.

Syllabus
I. Characterizing ocean waves and sea states (10/01/2020 )
• Introduction to class
• Description of waves
• Sea state characterization (wave-by-wave, spectral analysis)
• Wave observation techniques and databases

II. Linear wave theory (17/01/2020 )
• Linearization of the water wave problem
• Dispersion relation
• Wave kinematics and approximations in shallow and deep water
• Nonlinear wave theories (Stokes, Cnoidal, stream function)
Exercise: Using wave buoy measurements to generate scatter diagrams and to characterize
wave variability at an oshore study site.

III. Nearshore wave propagation (24/01/2020 )
• Wave energy
ux conservation
• Bathymetric refraction
• Wave shoaling
Exercise: Using a one-line model to calculate wave transformation in the surf zone (and
comparison to wave tank experiments).

IV. Coastal hydrodynamics (31/01/2020 )
• Characterization of wave breaking
• Wave breaking impacts (undertow, setup, longshore currents)
• Surf zone circulation (rip currents, eddies)
• Infragravity waves and impacts
• Wave-current interactions

V. Numerical modeling of wave propagation 1 (07/02/2020 )
• Review of important physical processes to model
• Dierentiating phase-averaged and phase-resolving models
• Presentation of phase-averaged (spectral) models
Exercise: Running TOMAWAC spectral wave propagation model to simulate wave propagation
in the nearshore zone.

VI. Numerical modeling of wave propagation 2 (14/02/2020 )
• Review of the Navier-Stokes equations
• Mild-slope equations
• Boussinesq-type models
• Fully nonlinear potential
ow theory models
• Navier-Stokes models (Eulerian and Lagrangian approaches)
Class presentations: Students work in groups to present the dierent families of deterministic
wave propagation models.

VII. Dynamics of a body in waves (28/02/2020 )
• Nondimensional numbers (Re, Fr, KC) and similitude
• Experimental approaches
• Academic models:
{ Linear theory
{ Fully nonlinear potential
ow theory
{ Navier-Stokes equations
Exercise: Wave load estimation on an oshore wind turbine foundation.

VIII. Modeling wave-body interactions (06/03/2020 )
• External forces applied on a body in waves : Froude-Krylov, diraction, drag, lift, buoy-
ancy
• Equation of motions
• Morison equation (small bodies)
• Diraction-radiation problem (large bodies)
• Second and higher-order eects
• Industrial codes and open research questions
Exercise: Use of wave scatter diagrams to calculate wave forces on a
oating body at the
selected oshore study site.

IX. Seminar about wave-structure interactions (presented by a representative from a company
working in the eld of marine renewable energy) (13/03/2020 )
Subject:
• Fixed and
oating oshore wind turbines
Objectives:
• Present pilot project, study site, existing and future technologies
• Discuss design criteria, challenges, current needs for research

X. Exam (20/03/2020 )