Acoustics and Waves in Fluids

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


Have the basic knowledge in acoustics and wave propagation in fluids

Palabras clave

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


I Acoustics

  1. Sound waves as linear perturbations of fluid mechanics equations.
  2. Sourd perception : deciBels, weighting curves.
  3. Wave propagation equations ; acoustic energy and intensity. Description in the frequency domain ; Helmholtz equation.
  4. Plane and spherical waves ; characteristic impedance; near field, far field.
  5. Reflection of waves at interfaces. Notion of impedance,
  6. Sound radiation from vibrating structures. Integral formulation.

II Waves in fluids

  1. Dispersive waves with the example of surface gravity waves,
  2. Propagation of a wave packet, phase velocity, group velocity, dispersion relation.
  3. High-frequency approximation and ray-tracing.

TP 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 = 0.6 Exam + 0.4 (BE + TP) BE = report on the work done on the muffler design TP = report on the TP on acoustic materials Exam = written exam of 2 h