Acoustics and Waves in Fluids

Lecturer(s): Didier DRAGNA, Gilles ROBERT
Course ⋅ 20 hTC ⋅ 24 hPW ⋅ 4 h


Many types of waves propagate in fluids. Among them, acoustic waves play a particular role in everyday life. They allow for human communication and are the support of music. The course is made of two parts. The first part aims at giving basic knowledge in acoustics. The second part extends the study to other types of waves in fluids (surface and internal gravity waves). It aims at understanding the phenomena of dispersion and propagation in inhomogeneous media.

Palabras clave

Acoustics, Sound, Noise, Waves, Dispersion relation, Phase and group velocities.


Elements of formalization and resolution of an acoustic problem (wave equation, boundary conditions, Green's function, ...). Characterization of acoustic fields (near and far fields, compact source, directivity, structure radiation).

Waves in fluids: notion of dispersion, group and phase velocities through the example of surface gravity waves. Propagation in inhomogeneous medium and geometric approximation.

Practical work on acoustic materials. BE on the design of a muffler.

Learning Outcomes

  • Basic calculations in acoustics (sound pressure levels, source power, dB, ...)
  • Kknowledge of elementary sources (plane and spherical)
  • Know the basics about the dB scale, the characterization of noise pollution and its perception
  • Master the general techniques to analyse linear propagation of waves in fluids: dispersion relation, high-frequency approximation


Final mark = 0.6Knowledge + 0.4Know-how Knowledge = final exam Know-how = continuous assessment