MEC_53456_EP - États de la mer, propagation des vagues et énergie des vagues océaniques (2024-2025)

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 di erent 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 di erent 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 o shore 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 • Di erentiating 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 di erent 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 o shore wind turbine foundation. VIII. Modeling wave-body interactions (06/03/2020 ) • External forces applied on a body in waves : Froude-Krylov, di raction, drag, lift, buoy- ancy • Equation of motions • Morison equation (small bodies) • Di raction-radiation problem (large bodies) • Second and higher-order e ects • Industrial codes and open research questions Exercise: Use of wave scatter diagrams to calculate wave forces on a oating body at the selected o shore 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 o shore 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 )