Ecole Nationale de l'Aviation Civile
Toutes les publications de l'ENAC en direct.
All ENAC publications.
This article presents a solution to intercept an agile drone by a team of agile drone carrying catching nets. We formulate the problem as a competitive Multi-Agent Reinforcement Learning (MARL) task. To address the problem of nonstationarity and catastrophic forgetting of agents overfitting to the current opponent strategy, we train the pursuers and the evader using Multi-Agent Proximal Policy Optimization (MAPPO) with Prioritized Fictitious Self Play (PFSP). We train the agents in a high-fidelity simulator using low-level control commands, collective thrust and body rates (CTBR), to achieve agile flights for both the pursuers and the evader. We compare the performance of...
Whistler‐mode waves play a crucial role in shaping magnetospheric electron dynamics. Using Juno's observations, we investigate these waves in Jupiter's post‐midnight‐to‐dawn magnetosphere, spanning 20–80 Jupiter radii. Our survey reveals that whistler‐mode waves predominantly occur in the lobes, while the magnetodisk remains largely devoid of such waves. Simultaneous electron measurements from JADE‐E, combined with dispersion relation analysis, indicate that these waves are likely driven by a mono‐directional electron population between 0.1 and 10 keV propagating anti‐Jupiter‐ward. Further controlled studies show that a local flux minimum at 0.3 keV in the electron energy...
Abstract Sustainability objectives in the aeronautical industry push companies toward novel aircraft propulsive systems (e.g., hybrid electric or hydrogen-based). Coupled with reliability constraints for certification, this creates a potentially highly complex propulsive architecture design. Thus, tools and methods are needed to explore this growing system design space efficiently. Several critical features have been identified by system architects in one of the leading companies in this domain: consideration of parallel functional chains for safety and redundancy reasons, systematic exploration of the design space, and the possibility to systematically generate from...
Structure-preserving discretization of intrinsic geometrically exact beams for explicit multibody dynamics
Mother of All BCI Benchmarks
Today, Air Transport suffers from a lack of capacity both in En-Route airspaces(ACC) and in terminal Area (TMA). This lack of capacity leads to a high congestion resulting in important delays for both airliners and users. One solution to reduce this congestion is to organize aircraft in airspace (route segregation or different Flight levels assignment) or in Time(sequencing). The aim of this Thesis is to develop sequencing automation algorithms in order to facilitate the ATC workload (Both En-Route and Approach). Through differents studies, works will steered on En-route aspects but also terminal airspaces identified as "Extended TMA" for which speed and Flight levels...
Nucleate boiling occurs in applications such as rocket cryogenic tanks and nuclear reactor cooling, where accurate thermal predictions are critical. Bubble growth near a wall is a strongly multiscale process involving contact-line and micro-layer regimes, the latter generating micrometric liquid films and intense heat fluxes. This work presents an accurate Direct Numerical Simulation (DNS) of bubble growth in the micro-layer regime using the in-house solver DIVA. The solver employs a sharp-interface method based on Level-Set tracking and the Ghost Fluid Method (GFM) to solve the incompressible Navier–Stokes equations. A significant advancement in this study is the...
Fuzz testing is a method used in software testing that involves inputting random or unexpected data into a system to identify vulnerabilities. Unlike deterministic methods, which test performance under controlled and predictable conditions, fuzz testing introduces variability to uncover hidden issues. This variability simulates real-world scenarios, uncovering weaknesses that might otherwise remain unnoticed. For instance, fuzz testing can effectively reveal how GNSS receivers respond to rapid signal fluctuations and other anomalous behaviors, situations often overlooked by standard tests. Unlike traditional methods that rely on predefined inputs, Collins Aerospace works...
Face au réchauffement climatique et à la dépendance aux énergies fossiles, cette thèse s’intéresse à la décarbonation du transport aérien. Elle propose une méthodologie visant à évaluer les besoins en énergie et en matières premières liés à l’introduction d’avions bas carbone et à l’usage de vecteurs alternatifs tels que les électrocarburants, biocarburants, hydrogène ou électricité. La première partie de cette thèse a mis en évidence les avantages et les défis technologiques propres à chaque vecteur énergétique. Des modèles de production ont ensuite été développés afin de quantifier les besoins énergétiques associés, révélant que l’électrocarburant est le plus énergivore...
Drawing on the observed regularity of typical trips, this study proposes a method for identifying commuting patterns without using the individual identifiers of public bike-share users. The approach combines an analysis of trip duration distributions, mixture models and logistic regression based on the posterior probabilities of belonging to the ‘fast’ and ‘typical’ journey categories.
