Paradot N.,Societe Nationale des Chemins de Fer Francais |
Gregoire R.,Alstom |
Stiepel M.,Alstom |
Blanco A.,Technology Management |
And 5 more authors.
Proceedings of the Institution of Mechanical Engineers, Part F: Journal of Rail and Rapid Transit | Year: 2015
The European Union Seventh Framework Programme research project AeroTRAIN aimed at delivering limit criteria for crosswinds to the €Rolling stock - locomotives and passenger rolling stock' Technical Specification for Interoperability (CR LOC&PAS TSI) and for class 2 trains of the high-speed rolling stock TSI (HS RST TSI). A first objective was the assessment of characteristic wind curve (CWC) for identified class 2 and conventional vehicles with low, but sufficient, crosswind stability (as proven by their safe operational records) on the EN 14067-6: 2010 single track with ballast and rails (STBR) standard configuration. In the same manner, and as a second objective, Reference CWC and limit criteria for class 1 trains of HS RST TSI were planned to be determined. For all these trains, the aerodynamic coefficients were obtained in a unique wind tunnel campaign using the STBR ground configuration. Their crosswind sensitivity was assessed against a calculated CWC obtained from vehicle dynamics simulations. The resulting database will allow the derivation of the relevant limit criteria still needed for vehicle authorization regarding crosswind stability. © MechE 2014.
Ziani R.,Societe Nationale des Chemins de Fer Francais |
Ouali M.-S.,Ecole Polytechnique de Montreal |
Artiba A.,Institute Des Science Et Techniques Of Valenciennes
International Journal of Production Research | Year: 2014
This paper addresses the problem of reliability analysis of in-service identical systems when a limited number of lifetime data is available compared to censored ones. Lifetime (resp. censored) data characterise the life of failed (resp. non-failed) systems in the sample. Because, censored data induce biassed estimators of reliability model parameters, a methodology approach is proposed to overcome this inconvenience and improve the accuracy of the parameter estimation based on Bayesian inference methods. These methods combine, in an effective way, system's life data and expert opinions learned from failure diagnosis of similar systems. Three Bayesian inference methods are considered: Classical Bayesian, Extended Bayesian and Bayesian Restoration Maximisation methods. Given a sample of lifetime data, simulated according to prior opinions of maintenance expert, a sensibility analysis of each Bayesian method is performed. Reliability analysis of critical subsystems of Diesel locomotives is established under the proposed methodology approach. The relevance of each Bayesian inference methods with respect to collected reliability data of critical subsystems and expert opinions is discussed. © 2012 Taylor & Francis.
Ladoux P.,National Polytechnic Institute of Toulouse |
Blaquiere J.M.,National Polytechnic Institute of Toulouse |
Caron H.,Societe Nationale des Chemins de Fer Francais |
Iannuzzi D.,University of Naples Federico II |
Coppola M.,University of Naples Federico II
IET Electrical Systems in Transportation | Year: 2015
Nowadays, in several European Railway networks, the old DC supply systems are severely limited by linevoltage drops. In some sectors, it is not possible to increase traffic or to operate locomotives at their nominal ratings. To increase the capacity of a DC supply system, without additional substations, the authors propose a new three-wire supply system which restores the overhead line voltage with multilevel DC choppers operating as voltage boosters. Circuits using a third wire with a negative or a positive polarity are considered and compared. Case studies are presented for the French and Italian rail networks. Finally, experimental results performed on a test platform of the French railways, are presented in the case of a double 1.5 kV supply system. © 2015 nstitution of Engineering and Technology.
Yang S.,Societe Nationale des Chemins de Fer Francais |
Yang S.,University Paris Est Creteil |
Cremona C.,Commissariat General Au Developpement Durable |
Cremona C.,University Paris Est Creteil |
And 2 more authors.
European Journal of Environmental and Civil Engineering | Year: 2010
Reynolds numbers play an important role in fluid dynamics, because flow separations and reattachments are often Reynolds-number dependent, even if the bodies have sharp edges. To satisfy Reynolds scaling in experiments, the model scale can be very large. Computational fluid dynamics (CFD) provides an interesting alternative to wind tunnel tests, especially when Reynolds effects have to be assessed for a design stage. In this paper, the particle strength exchange (PSE) of vortex methods is introduced for assessing Reynolds number effects on bridge deck cross-sections. For this purpose, this study analyses how the aerodynamic forces of two different bridges sections are influenced by these effects. The computation results with PSE are compared with wind tunnel tests. The relation between Strouhal numbers and Reynolds numbers are also analyzed and compared with experimental results. All the results show that the particle strength exchange method can be efficiently used to calculate Reynolds effects on 2-dimensional bridge deck sections. © 2011 Lavoisier, Paris.
Clin B.,French Institute of Health and Medical Research |
Clin B.,University of Caen Lower Normandy |
Andujar P.,French Institute of Health and Medical Research |
Andujar P.,University Paris Est Creteil |
And 19 more authors.
Annals of Occupational Hygiene | Year: 2012
Objectives: The hypothesis that asbestos exposure may have more specific associations with particular histological types of lung cancer remains controversial. The aim of this study was to analyze the relationships between asbestos exposure and pulmonary carcinoid tumors. Methods: A retrospective case-control study was conducted in 28 cases undergoing surgery for pulmonary carcinoid tumors and aged >40 years and in 56 controls with lung cancer of a different histological type, matched for gender and age, from 1994 to 1999, recruited in two hospitals in the region of Paris. Asbestos exposure was assessed via expertise of a standardized occupational questionnaire and mineralogical analysis of lung tissue, with quantification of asbestos bodies (AB). Results: Definite asbestos exposure was identified in 25% of cases and 14% of controls (ns). Cumulative asbestos exposure was significantly higher in cases than in controls (P < 0.05), and results of the quantification of AB tended to be higher in cases than in controls (24 and 9% had >1000 AB per gram dry lung tissue, respectively, P = 0.09). Mean cumulative smoking was lower in cases than in controls (P < 0.05). Conclusions: This study argues in favor of a relationship between asbestos exposure and certain pulmonary carcinoid tumors. © 2012 The Author.