Impact of the Automotive Aerodynamic Control on the Economic Issues

Sustainable development associated with the need to reduce the energy consumption and to offer more creative freedom to the automobile designers requires looking for new solutions of control without appendix added nor geometrical modification. Among these solutions, the active flow control by fluidic actuators constitutes an interesting alternative. Various configurations of control are thus tested in order to reduce the aerodynamic drag. The results show that protocols based on control by suction, blowing or intermittent jet allows reducing the aerodynamic drag and consequently the consumption and CO2 emissions

Enhanced Navigation System for Road Telematics

Navigation systems are becoing standard in-vehicle equipment. In the future these technologies will take place in new systems called Intelligent Integrated Road Safety Systems. Reaching this high level of integration and these requirements needs more precise digital map databases and advanced navigation technologies

De l'évolution du GPS à la navigation pédestre

Ces dernières années, les méthodes de localisation ont pris un essor important dans de nombreuses activités humaines. Connaître sa position a toujours été une préoccupation de l'homme qui a développé, au fil du temps, les moyens nécessaires pour s'orienter et se déplacer au bon endroit

Challenging EGNOS in the Swiss Alps

In view of the operational validation of EGNOS, some early tests are being performed with the EGNOS System Test Bed (ESTB). This prototype has been broadcasting an EGNOS-like signal since early 2000. The performance of ESTB is reduced compared to the full deployed EGNOS, but it gives the opportunity to test EGNOS equipment and gain experience. Eurocontrol, skyguide and the Swiss Federal Institute of Technology in Lausanne (EPFL) are active in data collection and analysis in order to study the signal-in-space performance for the civil aviation users. The objective of this work was to analyse the system’s performance during flight tests in the Swiss Alps where the topography is a challenge for satellite-based navigation systems. Sion regional airport was selected for its location in a valley surrounded by very high mountains. Moreover, the use of EGNOS on regional places is expected to bring significant operational benefits. A new GNSS procedure including both the approach and a special missed-approach with a 89° turn in the valley was designed for these tests. A total of 13 approaches and missed-approaches were flown in November 2002 by a Dornier 128 belonging to the Technical University of Braunschweig (TUBS) and a King Air 100 belonging to SENASA (Sociedad para las Enseñanzas Aeronáuticas Civiles S.A.). Around 8 hours of data were recorded from different receivers on the ground and in the air. This paper shows that the accuracy and integrity obtained during the tests with the EGNOS System Test Bed fulfils the stringent requirements of civil aviation even in a difficult environment. However, some progress still has to be made on the availability and continuity parameters. This will be the case once the real EGNOS will be operational. It also demonstrates that EGNOS-based procedures are feasible and that it could bring important operational benefits to regional places with a limited ground navigation infrastructure

Mechanical integrity of thin inorganic coatings on polymer substrates under quasi-static, thermal and fatigue loadings

The interplay between residual stress state, cohesive and adhesive properties of coatings on substrates is reviewed in this article. Attention is paid to thin inorganic coatings on polymers, characterized by a very high hygro-thermo-mechanical contrast between the brittle and stiff coating and the compliant and soft substrate. An approach to determine the intrinsic, thermal and hygroscopic contributions to the coating residual stress is detailed. The critical strain for coating failure, coating toughness and coating/substrate interface shear strength are derived from the analysis of progressive coating cracking under strain. Electro-fragmentation and electro-fatigue tests in situ in a microscope are described. These methods enable reproducing the thermo-mechanical loads present during processing and service life, hence identifying and modeling the critical conditions for failure. Several case studies relevant to food and pharmaceutical packaging, flexible electronics and thin film photovoltaic devices are discussed to illustrate the benefits and limits of the present methods and models. © 2010 Elsevier B.V. All rights reserved