Êtes-vous un étudiant de l'EPFL à la recherche d'un projet de semestre?

Travaillez avec nous sur des projets en science des données et en visualisation, et déployez votre projet sous forme d'application sur GraphSearch.

Découvrez-en plus sur les applications Graph.

Concept

Hélicoptère

Un hélicoptère est un aéronef dont la et la propulsion sont assurées par une voilure tournante, couramment appelée rotor, et entraînée par un ou plusieurs moteurs. La majorité des hélicoptères utilise un seul rotor de sustentation et un rotor ou autre dispositif anticouple, les autres solutions sont des bi-rotors contrarotatifs placés sur le même axe, sur deux axes convergents, en tandem ou côte à côte. L'histoire de l'hélicoptère commence au début du mais les progrès sont nettement plus lents que ceux de l'avion. L'utilisation intensive des hélicoptères lors des guerres d'Algérie et du Viêt Nam et le développement des turbomachines marquent un tournant majeur pour apporter la preuve de ses capacités opérationnelles civiles ou militaires. Comparé aux aéronefs à ailes fixes, l'hélicoptère est d'une conception plus complexe, sa maintenance est plus exigeante et le coût de l'heure de vol est plus élevé. Son aptitude à décoller et atterrir sur des terrains étroits et non préparés le

À propos de ce résultat

Cette page est générée automatiquement et peut contenir des informations qui ne sont pas correctes, complètes, à jour ou pertinentes par rapport à votre recherche. Il en va de même pour toutes les autres pages de ce site. Veillez à vérifier les informations auprès des sources officielles de l'EPFL.

Publications associées (11)

Publications associées

Chargement

Personnes associées (1)

Personnes associées

Chargement

Unités associées (1)

Unités associées

Chargement

Concepts associés (45)

Concepts associés

Chargement

Cours associés (6)

Cours associés

Chargement

Séances de cours associées (8)

Séances de cours associées

Chargement

Embedded ultra-low power driver for a 7.2g helicopter and IrDA remote control

Patrick Clerc

In a previous project, a 7.2g helicopter made of carbon was designed and realized at the LAI. The goal of this project is to design and realize a tiny receiver and a remote capable of driving the helicopter from a distance of 2 to 4 meters. Challenges are here to make the receiver small and light enough to be embedded in the helicopter without disturbing the flight. Ultra-low consumption is also required. Both emitter and receiver will have to be designed and mounted by the student. The microcontroller is to be chosen in the MSP430F21x2 family. Well-known for their low-power consumption, they also possess an IrDA serial communication interface which will be used for a bi-directional communication between the helicopter and the remote. The remote will have to control 3 channels (lift, yaw and eventually pitch) and display the battery level of the helicopter.

2011

Chargement

Survival of rotational alignment in H-2 scattering from Si(100)

Christopher Scott Reilly

We report a state-prepared, state-resolved study of rotational scattering of a diatomic molecule from a solid surface. Specifically, H-2 molecules with 80 meV kinetic energy are rotationally aligned in the j = 3 rotational state via stimulated Raman pumping and then scattered from a Si(100) surface at normal incidence. The rotational alignment of the scattered molecules is determined by measuring, for both the incident and scattered molecules, the ionization yield of a probe laser, tuned to selectively ionize molecules in the j = 3 rotation level, as the probe laser polarization is rotated. The measurement is performed for two initial rotational alignments: a "helicoptering " alignment with the bonds constrained to lie primarily parallel to the surface and a "cartwheeling " alignment with the bonds lying primarily normal to the surface. For both initial alignments, the modulation of the probe ionization yield with laser polarization for the scattered molecules is pronounced, although significantly weaker than the modulation measured for the incident molecules. This indicates a significant modification but not a complete elimination of the initial alignment. The modulation is found to be stronger for the scattered molecules originating in the cartwheeling alignment than for the helicoptering alignment. These results contribute toward an improved understanding of the role of rotational motion in molecule-surface dynamics.

AIP Publishing2021

Chargement

Characterisation of blade tip vortices by simultaneous time-resolved velocity and density field measurements

Karen Ann J Mulleners

The flow field around a helicopter is dominated by strong coherent vortices originating from the blade tip as a result of the pressure difference between suction and pressure side and a high radial velocity at the tip (Leishman, 2001; Green and Acosta, 1991). These vortices have a strong impact on the rotorcraft acoustics and performance due to its interactions with the rotor blades and the helicopter fuselage (Conlisk, 2001). Detailed knowledge of the vortex development, in particular of the formation process, and the scaling of characteristic parameters, e.g. vortex size and strength, are necessary for the design and the optimisation of vortex control measures. Due to the complexity and the inherent unsteady character of the vortex dynamics, this can only be achieved by time-resolved measurements of the velocity and density field simultaneously.

2012

Chargement

Aéronef

vignette|Une montgolfière. Un aéronef est un moyen de transport capable de s'élever et de se mouvoir en altitude, au sein de l'atmosphère terrestre. Les sciences et technologies permettant de constru

Aéroplane

vignette|Exemple d'un aéroplane Un aéroplane est un aérodyne à voilure fixe. Cette notion regroupe :

les avions, motorisés ;
les planeurs.

Historique Le premier projet français d'aéro

Drone

vignette|Un Parrot AR.Drone devant un Dassault Rafale. vignette|Un drone de reconnaissance EADS Harfang lors du Salon du Bourget de 2007. vignette|Drone civil OnyxStar Fox-C8 XT en vol. vignette|Dron

ME-445: Aerodynamics

This course will provide the fluid dynamic background to understand how air flows around two- and three-dimensional wings and bodies and to understand the aerodynamics forces and moments acting on the objects as a result of the air flow.

MSE-440: Composites technology

The latest developments in processing and the novel generations of organic composites are discussed. Nanocomposites, adaptive composites and biocomposites are presented. Product development, cost analysis and study of new markets are practiced in team work.

EE-585: Space mission design and operations

This course is a "concepts" course. It introduces a variety of concepts in use in the design of a space mission, manned or unmanned, and in space operations. it is at least partly based on the practical space experience of the lecturer.