Wave phenomena in the sea environment. General principles of wave motion. Principle of Heron-Fermat. Ray theory. Reflection, refraction and diffraction in stratified and inhomogeneous media. Representation of wave field in waveguides with non-planar boundaries.
Variational principles in the frequency domain and in the time-domain. Coupled-mode theory. Green’s functions in waveguides with general boundaries. Disturbance field by a localized scatterer in a waveguide. Numerical solutions of waveguide-scattering problems. Overview of basic theorems and equations of Fluid Mechanics.
Wave equations with application to the propagation of surface gravity water-waves and hydroacoustic waves. Boundary conditions. Radiation conditions. Formulation of the waveguide problem in stratified and inhomogeneous media. Simple solutions obtained by separation of variables (in infinite and semi-infinite strips). Propagating and evanescent modes. Energy theorems. Group velocity. Green’s functions in simple waveguides.
Technological applications and environmental problems of gravity waves (interaction of water waves with structures and the marine/coastal environment, wave energy systems). Technological applications and environmental problems of underwater acoustics (underwater telecommunications, tomographic applications, marine environment remote sensing, shipping noise).
- Teacher: Κωνσταντίνος Μπελιμπασάκης
ECTS : 4
Language : el, en
Learning Outcomes : The course aims to offer to the students:
1) The necessary theoretical background for understanding the basic waveguide phenomena in the sea and coastal environment concerning the physics of acoustic wave propagation in multilayered and inhomogeneous media, such as the sea acoustic waveguide, and the propagation of surface gravity waves in a strip of water of constant depth and general bathymetry, interacting with the seabed.
2) Specialized knowledge of the principles governing the above phenomena, the mathematical modeling of the relevant initial and boundary value problems, and the presentation of basic solution methods and techniques.
3) Highlighting the advantages of the above methods in a number of applications in the following directions: Wave energy, impact on structures, impact on the coastal environment. Determination of wave conditions in marine/coastal areas. Underwater communication, ocean tomography, remote sensing of the marine environment. Shipping noise.
Acquired Skills: Upon successful completion of the course, the student will be able to:
1) Understand the basic waveguide phenomena in the marine and coastal environment associated with underwater acoustics and water waves.
2) Be able to use basic results of the theory to predict water wave and acoustic wave propagation in the sea and coastal environment.
3) Be able to use the numerical methods described in the course for basic calculations of the wave fields and energy related quantities.