Acoustics - Thermal

This UE is made up of two blocks of 18 hours each (9h CM+ 9h TD).

For the first "acoustic" block, after the establishment of the propagation equation of mechanical vibrations in an infinite medium, the plane wave solutions will be presented. The emphasis will then be put on the notion of scalar potential. The solutions in spherical waves will be presented. A large part will be devoted to the notion of acoustic impedance. The energetic aspects will also be discussed. Various applications (in particular ultrasonic) will be discussed.

The second "thermal" block of the EU consists in studying the heat transport properties in solids and fluids in stationary regime (independent of time). We first define the diffusive and convective heat transfer regimes, and introduce the Fourier equation relating the heat flow to the temperature variation via the thermal conductivity or the conducto-convective coefficient. We then establish the heat propagation equation that we apply to the simple cases of walls and pipes. We then recall the main laws describing heat transfer by radiation (Planck's law, Stefan-Boltzmann's law) and study the case of radiative flux between two bodies under total influence. All this knowledge will be used to perform the heat balance of homogeneous or composite walls, building models, bars and fins. We will also treat the case of heat exchangers.

Acoustics part: master all the elements of vibratory physics applied to acoustic waves (audible or ultrasonic) in order to be able to understand the current applications: non-destructive testing, microscopies, 2D and 3D medical ultrasound, elastography...

Thermal part: Master all the tools for calculating heat transfer by conduction, conducto-convection, and radiation, mentioned above. Know how to apply these tools to the calculation of the heat balance of everyday systems: walls, pipes, houses, bars and fins, heat exchangers.

Notions of mechanics, thermodynamics, and mathematics

Recommended prerequisites*: Notion of continuum mechanics, partial differential equations.

100% CT

CM : 18 h

TD : 18 h