| Course label : |
Complex flows: the limits of empiricism |
| Teaching departement : |
CMA / |
| Teaching manager : |
Mister ALEXANDRE MEGE REVIL / Mister CHRISTOPHE CUVIER |
| Education language : |
English |
| Potential ects : |
0 |
| Results grid : |
|
| Code and label (hp) : |
IFU_CPD_ECL - Écoul Compl : Lim empirisme |
Education team
Teachers : Mister ALEXANDRE MEGE REVIL / Mister CHRISTOPHE CUVIER / Mister JEAN-MARC FOUCAUT / Mister JORAN ROLLAND / Mister LE YIN / Mister MARTIN OBLIGADO / Mister MOHAMMAD AHMAD
External contributors (business, research, secondary education): various temporary teachers
Summary
Many objects in everyday life and industry involve the movement of a fluid. This movement is very often complex and turbulent because it is at a very large Reynolds number. The turbulence that is generated is still a very poorly understood phenomenon and tends in any case to reduce the performance of the application and its lifetime. As most of these systems have no valid theory, they have been designed on an empirical basis, which means that their energy balance is certainly far from optimal. The most striking example is the aircraft, which was initially conceived by biomimetic (Leonardo Da Vinci and then Lilienthal) and finally finalized by comparative tests of hundreds of shapes by the Wright brothers. Through increasingly advanced experimental approaches coupled with numerical simulation, their performance has improved but not drastically, so that a 25% gain in drag is targeted and possible in the short term. It is clear that since the 1950s the shape of aircraft has not changed significantly. Given the inability to find a technological breakthrough in airflow, the improvement of their energy performance is currently based on lightening the structure by using more and more composite materials that are difficult to recycle and repair. The same conclusions apply to land transport or wind turbine. Industrial mixers have also been designed empirically. A more homogeneous mixture is obtained by injecting more energy into the blades to create more turbulence that promotes mixing. This time turbulence is the key to the process, however, their energy efficiency is far from optimal. Finally, the failure to control flow turbulence gives heavy fluctuating loads on structures (mixer blades, wind turbine blades, aircraft wings, turbomachinery, etc.), significantly reducing their service life.
In these examples, it is clear that the absence of a reliable theory to predict turbulence has led to the construction of aerodynamic or hydraulic machines by an empirical or semi-empirical approach that is far from optimal. To reduce the energy requirement of these systems, very High Tech solutions are implemented for often low gains or requiring the search for solutions to correct new problems introduced (for example, direct injection on gasoline engine make them producing more particles than a diesel engine with a particle filter). If a theory of turbulence were known, it would then be possible to design more efficient, effective, simple and robust devices that are fully in line with the principles of Low Tech for a healthier management of primary resources. Unfortunately, we are not there yet. The objective of this module is to raise awareness of this issue among engineering students at Centrale Lille and to introduce them to the current tools for coupling experiments and numerical simulations, which partly respond to this point in order to design products with a much lower ecological impact. This approach is also in line with the European objectives of improving energy efficiency by 20% by 2020 and 30% by 2030.
Educational goals
At the end of the course, the student will be able to:
- Analyze, identify and understand problems related to flow complexity on various applications (mixers, internal flows, aerodynamics, etc.) and the limitations of current approaches (competency C2.1: Represent and model, grade level competent, D intermediate).
- Model a flow studied by coupled experiments/numerical simulations approaches with a critical look at theirs results (competence C2.2: Solve and Arbitrate, grade A competent level, D intermediate).
- Propose innovative approaches or solutions to the turbulence problems encountered (competence C1.1 Emerging, grade A competent level, D intermediate).
Sustainable development goals
Knowledge control procedures
Continuous Assessment
Comments: During the module, two 4-hours sessions of experimental tutorial/practical work (TDTP) and 3 4-hours sessions of digital practical work will be carried out and evaluated through reports in groups of 4. The average of the evaluations of the reports will constitute the final evaluation. They must therefore be professional and show a certain level of understanding of the problem of turbulence.
Online resources
Course support and practices on moodle
Pedagogy
Mixed course/exercices seminars complemented by experimental and numerical simulations tutorial/practicals with an emphasis on practical application and autonomous work. The module will be taught entirely in English.
Sequencing / learning methods
| Number of hours - Lectures : |
0 |
| Number of hours - Tutorial : |
8 |
| Number of hours - Practical work : |
0 |
| Number of hours - Seminar : |
0 |
| Number of hours - Half-group seminar : |
0 |
| Number of student hours in TEA (Autonomous learning) : |
0 |
| Number of student hours in TNE (Non-supervised activities) : |
0 |
| Number of hours in CB (Fixed exams) : |
0 |
| Number of student hours in PER (Personal work) : |
0 |
| Number of hours - Projects : |
0 |
Prerequisites
No prerequisites are really necessary. However, it is recommended to have completed the "fluid transport" and/or "aerodynamics" modules. It is also advisable to have a good knowledge of the mechanics of continuous media (stress, deformation, gradient operator, divergence, rotational and laplacian as well as Einstein's notation conventions).
Maximum number of registrants
Remarks