National Engineering School of Mechanical and Aeronautical Engineering
Poitou - Charentes, France
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Tan L.-M.,Center for Biomedical and Life science | Sem Z.-Y.,Center for Biomedical and Life science | Chong W.-Y.,Center for Biomedical and Life science | Hendra,National Engineering School of Mechanical and Aeronautical Engineering | Kwan W.L.,Singapore University of Technology and Design
Organic Letters | Year: 2013

We report the development of a heterogeneous catalyst system on continuous flow chemistry. A palladium (Pd) coated tubular reactor was placed in line with copper (Cu) tubing using a continuous flow platform, and a Sonogashira C-C coupling reaction was used to evaluate the performance. The reactions were favorably carried out in the Cu reactor, catalyzed by the traces of leached Pd from the Pd reactor. The leached Pd and Cu were trapped with a metal scavaging resin at the back-end of the continuous flow system, affording a genuine approach toward green chemistry. © 2012 American Chemical Society.

Agency: European Commission | Branch: H2020 | Program: CSA | Phase: MG-1.6-2014 | Award Amount: 673.32K | Year: 2014

The proposed action is expected to contribute to better meeting the needs of the aerospace sector for highly skilled workforce and to enhance the mobility of aerospace students and professionals across Europe. Taking into consideration the complex skills needed by the aerospace sector, the action will develop the required learning outcomes and competence profiles for aero-engineering curricula and propose the aerospace specific accreditation criteria that would complement the existing European, national or regional accreditation systems for engineering education. The action will be developed in three distinct phases. The first phase is a conception phase. The learning outcomes and procedures will be defined looking at current practices and involving the main stakeholders of the higher education chain, from Universities to Industries and Research Establishments. The result should be a staged accreditation system, thereby gradually enhancing the quality level of the higher education degrees. The second phase is an implementation phase. The identified processes are tested on 6 aerospace curricula, from different EU countries. The third phase is a refinement phase. The results of the testing phase are compared to the expectations and the processes are updated taking into consideration the lessons learned from the testing phase. Suggestions for harmonizing the curricula and simultaneously developing knowledge and emerging technologies as well as facilitating students exchanges across the EU will be proposed. In parallel to the three phases, a dissemination and outreach activity is implemented to diffuse the culture of best practices among the EU higher education courses in the area of aerospace engineering and attract talented students to such studies. The consortium members include representatives of aerospace industry, research establishments and education institutions, participating in the major existing EU networks such as PEGASUS, EASN, ENAEE, EREA and EACP.

Yan L.,Beihang University | Chen I.-M.,Nanyang Technological University | Lim C.K.,National Engineering School of Mechanical and Aeronautical Engineering | Yang G.,Singapore Institute of Manufacturing Technology | Lee K.-M.,Georgia Institute of Technology
IEEE/ASME Transactions on Mechatronics | Year: 2012

This paper presents a three-degree-of-freedom permanent magnet (PM) spherical actuator with an iron stator. The major contribution of this paper is to study the effect of iron stator on the magnetic field and torque output of the electromagnetic spherical actuator quantitatively and qualitatively. It could be helpful for actuator design optimization. Based on the poles arrangement and the iron boundary, the magnetic field of the PM-pole rotor and the actuator torque are formulated analytically. The effect of iron stator on the magnetic field and torque output is analyzed with respect to structural parameters. The result shows that the iron stator can increase the radial component of the flux density and thus the actuator torque output significantly. © 2012 IEEE.

Yu J.,Xiamen University | Liu D.,National Engineering School of Mechanical and Aeronautical Engineering | Tao D.,Intelligent Systems Technology, Inc. | Seah H.S.,Nanyang Technological University
IEEE Transactions on Systems, Man, and Cybernetics, Part B: Cybernetics | Year: 2012

How do we retrieve cartoon characters accurately? Or how to synthesize new cartoon clips smoothly and efficiently from the cartoon library? Both questions are important for animators and cartoon enthusiasts to design and create new cartoons by utilizing existing cartoon materials. The first key issue to answer those questions is to find a proper representation that describes the cartoon character effectively. In this paper, we consider multiple features from different views, i.e., color histogram, Hausdorff edge feature, and skeleton feature, to represent cartoon characters with different colors, shapes, and gestures. Each visual feature reflects a unique characteristic of a cartoon character, and they are complementary to each other for retrieval and synthesis. However, how to combine the three visual features is the second key issue of our application. By simply concatenating them into a long vector, it will end up with the so-called curse of dimensionality, let alone their heterogeneity embedded in different visual feature spaces. Here, we introduce a semisupervised multiview subspace learning (semi-MSL) algorithm, to encode different features in a unified space. Specifically, under the patch alignment framework, semi-MSL uses the discriminative information from labeled cartoon characters in the construction of local patches where the manifold structure revealed by unlabeled cartoon characters is utilized to capture the geometric distribution. The experimental evaluations based on both cartoon character retrieval and clip synthesis demonstrate the effectiveness of the proposed method for cartoon application. Moreover, additional results of content-based image retrieval on benchmark data suggest the generality of semi-MSL for other applications. © 1996-2012 IEEE.

Agency: European Commission | Branch: FP7 | Program: JTI-CS | Phase: JTI-CS-2012-2-SFWA-01-049 | Award Amount: 649.33K | Year: 2014

This project is to validate a cleaning device capable of clearing out small debris from the leading edges of business jets or airliners, to keep the flow as laminar as possible on the leading edge of the wing. The cleaning concept will be compatible with the surface treatment of the leading edge of commercial aircrafts. Typically this concerns the contamination of leading edges by insect impact. At first, the system will be designed and a prototype manufactured. In parallel, aerodynamic and stress models will be studied. Then ground experiments including tests in a wind tunnel will be performed, in view of prototype validation.The prototype will be subsequently modified and validated. Conclusions will help for the industrialisation of the cleaning system. The consortium will be led by EPFL, who co-ordinated a preliminary project on the design of such cleaning devices in the CleanSky call 3 CLEANLE, with several partners for manufacturing, consulting, experiment running and analysis, including a design office SME, and university windtunnel experts. The project will lead to a test prototype. The present project will push the concepts, that have attained a Research Technology Readiness Level, TRL near to TRL3 (research to prove feasibility), to evolve on the system/subsystem model and prototype demonstrator of a technology demonstration of TRL 6.

Agency: European Commission | Branch: H2020 | Program: CS2-IA | Phase: JTI-CS2-2015-CFP02-AIR-02-08 | Award Amount: 691.76K | Year: 2016

This proposal addresses the specific aeronautical challenge relative to the improvement and optimization of nacelle/engine integration to reduce drag and save weight thanks to high technology devices leading to significant CO2 savings. The ultimate goal of this proposal is to replace the today ice protection systems mounted on the surfaces of engine intakes by a two-phase passive thermal system with the following main benefits: Reduction of fuel consumption and raise of the engine effectiveness by the use of a highly efficient thermal system for the extraction of heat load from the engine to the protected surface (high heat transfer capacity compared to the two-phase system mass); Decrease of mass and ease of thermal icing protection integration by removing the today electro-thermal and pneumatic usual device used to collect power from power plant; Increase of reliability of a critical function such as anti-icing by removing active control and operations; Lower impact on environment and operating cost reduction through the use of passive and maintenance free thermal equipment. At two-phase system level, the main innovation will concern the adaptation of the space qualified product to the specific aeronautical requirements. TRL6 is considered for the two-phase product in order to enable the European aeronautical communities to propose more efficient aircrafts with less environmental impacts. The most relevant characteristics to be assessed and managed through this project are: The severe thermal and mechanical environment around the engine and its nacelle and The specific geometry of the protected surface. This project will so contribute to the strengthening of the competitiveness of the European industry by introducing two-phase heat management systems contributing to the reduction of CO2 emissions and airplane noise, toward an eco-conception and an eco-utilization point of view.

Longere P.,Higher Institute of Aeronautics and Space | Dragon A.,National Engineering School of Mechanical and Aeronautical Engineering
Mechanics of Materials | Year: 2015

Ductile fracture of metals by void nucleation, growth and coalescence under positive stress triaxiality is well admitted. This is not the case when metals are submitted to negative stress triaxiality. The present work aims at contributing to a better understanding of the competition between micro-mechanisms at the origin of failure of metals when submitted to shear-pressure loading at low and high strain rates. With this aim in view, experiments were carried out on Ti-6Al-4V shear-compression samples involving a stress triaxiality range comprised between -0.2 and -0.5. Results show that the material failure is the consequence of a void growth induced process. At high strain rate, due to the localization of the deformation within adiabatic shear bands, the failure of the material occurs earlier, leading to maximum shear strain smaller at high strain rate than at low strain rate. Impact tests were also carried out on Kalthoff and Winkler type double notched plates. They showed that the interaction between tension and shear waves leads to a complex Mode I-Mode II crack propagation. © 2014 Elsevier Ltd. All rights reserved.

Ezzahri Y.,National Engineering School of Mechanical and Aeronautical Engineering | Joulain K.,National Engineering School of Mechanical and Aeronautical Engineering
Physical Review B - Condensed Matter and Materials Physics | Year: 2014

The natural transition from the radiative regime to the conductive regime of heat transfer between two identical isotropic nonmagnetic dielectric solid materials is questioned by investigating the possibility of induced phonon transfer in vacuum. We describe the process in a general way assuming a certain phonon coupling mechanism between the two identical solids, then we particularly illustrate the case of coupling through the Casimir force. We analyze how this mechanism of heat transfer compares and competes with the near field thermal radiation using a local model of the dielectric function. We show that the former mechanism can be very effective and even surpass the latter mechanism depending on the nature of the solid dielectric materials, the distance gap between them, as well as the operating temperature regime. © 2014 American Physical Society.

Agency: European Commission | Branch: H2020 | Program: CS2-RIA | Phase: JTI-CS2-2015-CFP02-LPA-01-11 | Award Amount: 1.50M | Year: 2016

The HASTECS project aims at supporting the demonstration of radical aircraft configurations (CS-2/WP1.6) by means of models and tools development that can help the designers in assessing main benefits of architectures and power management of hybrid electric propulsion. The proposed consortium involves all competences to face the huge complexity of this process. All academic researchers will gather their expertise to optimize the overall hybrid power chain, starting with electric and thermal components up to system integration by taking into account main environmental constraints. Assessments will be integrated at the system level and will include design and analysis of main components of the hybrid power chain: electric machines and related cooling, cables, power electronics and related thermal management. This system integration will take into account the main environmental constraints, especially partial discharges due to new high power and ultra-high voltage standards. The HASTECS project proposes to reach aggressive targets with a strong increase of specific powers for the main components; We especially target to double the specific power of electric machines from 5kW/kg for 2025 to 10kW/kg for 2035 while specific powers of converters would evolve from 15kW/kg for 2025 to 25kW/kg for 2035: this expected gap, when installing 4 invertermotor drives of 1.5MW, will lead to a weight reduction of 1.8 tons, which will offer a significant fuel burn reduction estimated at 3.5% for a short range (~300nm) flight. Additional fuel burn reduction will be obtained thanks to several technological steps as on auxiliary sources (batteries, fuel cells, etc) and by optimizing the overall system sizing integrating the power management. Recent assessments estimate that the reduction of total energy provided by both Gas Turbines and auxiliaries (batteries of fuel cells) of the most promising electric hybrid architecture may go beyond 20% for a 300nm regional flight!

Agency: European Commission | Branch: FP7 | Program: JTI-CS | Phase: JTI-CS-2012-1-SGO-02-039 | Award Amount: 287.63K | Year: 2012

The increase of reliability of high speed electrical machines is a crucial goal in the industrial point of view. The use of electrical equipment undergoing hard operating conditions (rotational speed, heat dissipations) leads to the development of efficient, passive and reliable device, capable of extracting heat from those systems. As well as being an excellent passive system transferring large quantities of heat, the axial rotating heat pipe satisfies all requirements because of its reduced size and small working fluid loads. First, we propose the improvement of existing experimental set up to characterize these two phase-flow devices operating under very high radial acceleration levels. Many parameters are involved in the behavior of such a complex system: inside geometry, nature and charge in two-phase fluid and external surroundings (transient dissipations, range of temperature of cold source,..). Evaporator dissipations will be provided by induction while cooling of condenser achieved by air flow in existing high security area. Temperature evolutions of wall heat pipe will be measured by Infra red camera and heat balances will be made at several levels (inductor, heat pipe, cooling air flow). Different filling ratios and geometry heat pipes will be investigated to get deep understanding of heat transfer performances from low to high rotational speed. In the same time and after a strong state of the art of the modelisation of transfer in heat pipe at high rotational speed, numerical modelisation will be performed at different levels: microscopic liquid/vapour level (finite volume model) then at system level by building and validate nodal networks to reach the objective of certifying the performances of each model approach versus experimental results. Thanks to these developments, we will be able to propose optimization of high rotational heat pipes for heat transfer in motorized turbomachine context.

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