Acoustics - Thermal

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

For the first "acoustics" block, after establishing the equation for the propagation of mechanical vibrations in an infinite medium, plane-wave solutions will be presented. Emphasis will then be placed on the notion of scalar potential. Spherical wave solutions will be presented. A large part will be devoted to the notion of acoustic impedance. Energy aspects will also be discussed. Various applications (particularly ultrasonic) will be covered.

The second "thermal" block of the course studies heat transport properties in solids and fluids under stationary (time-independent) conditions. We first define diffusive and convective heat transfer regimes, and introduce the Fourier equation linking heat flow to temperature variation via thermal conductivity or the conducto-convective coefficient. We then establish the heat propagation equation, which we apply to the simple cases of walls and pipes. We then review 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 carry out heat balances for homogeneous or composite walls, building models, bars and fins. We'll also look at heat exchangers.

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

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

Notions of mechanics, thermodynamics and mathematics

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

100% CT

CM: 6 p.m.

TD: 18 h