MEC594 - Aérodynamique et hydrodynamique (2023-2024)

Lutz Lesshafft - Ladhyx
E-mail : lesshafft@ladhyx.polytechnique.fr
Tel: 01.69.33.52.56

Christophe Clanet - Ladhyx
E-mail : clanet@ladhyx.polytechnique.fr
Tel: 01.69.33.52.58

General description

The development of new generations of aerospatial (atmospherical and spatial planes, missiles, launchers), maritime (vessels, submarines, deepwater exploration machines, platform exploitation platforms), or land vehicles raises many challenges in Fluid mechanics that it must be apprehended before the prototype building stage. Increasing performance constraints with cost concern involve the following aspects:

• mobility (velocity, maniability).
• consumption (propulsion efficiency).
• security and comfort (stability and control, vibrations).
• radiated noise (this option can have internships with acoustical coloration).

In this competition, modeling skills from fundamental research are a crucial asset.

Topics

A lot of encountered issues of complex flows are common to aerodynamics and hydrodynamics as they are related to fundamental phenomena like turbulent, stalls, vortical wakes. The same digital models () and tests () are therefore often implemented to address the issues of subsonic aerodynamics and issues of hydrodynamics. However, aerodynamics and hydrodynamics are distinguished by specific effects.

We can note in hydrodynamics:

• the high mass of fluid (gravity and inertial interactions between fluid and structures),
• the presence of free surface (diffraction-radiation of the swell by obstacles),
• the existence of two-phase mix (cavitation phenomenon).

In aerodynamics, the specific issues are those related to high velocity:

• effects of air compressibility (shock wave),
• thermal effects
• high temperature (combustion, hypersonic flows) or high altitude (rarefaction) phisicochemical effects.

In recent years, significative progresses have been made in knowledge and prediction of complex flow, both therorically or digitally (digital methods and use of supercomputers, turbulence theory) and experimentally (precise measurement through laser velo, new large scale tests).

Aerodynamics and hydrodynamics are old field that are currently undergoing profound change is largely due to the development of the major computing and experimental resources. This option offers to put students in direct contact with the most recent aspects of these fields and industrial challenges they face.

Internships

Subjects of internships can be of a fundamental nature (sharp study of complex phenomena in simple configurations) or more applied (more global study of reality configurations).

The focus is on application of analytical methods, implementation or improvement of digital codes or acquisition, treatment and interpretation of experimental data. Different aspects are often associated, the subject is best suited to pair work.

Examples of proposed internships

The catalogue of internships from the past year is available. Most of the internships are now done abroad.

Process in case of interest

this option works by proposing an annual list of opportunities suggested by our contacts in September. This list results in a catalog provided to students who request it during the options' of the Mechanics Department or by sending an e-mail to the person in charge. We encourage students to choose a topic within the catalog as we know the national and international organizations offering these courses. However, we can also finalize other internships with a student with a very specific idea and motivation. Please contact us after reading the catalog AND NOTE THAT THE INTERNSHIP DEFINITION MUST BE CARRIED OUT IN CONSULTATION WITH THE RESPONSIBLES OF THE OPTION. INTERNSHIPS WITHOUT SUFFICIENT SCIENTIFIC CONTENT WILL BE REFUSED.

Course language: French