Louis-Marie Cleon

High current permanent discharges in air induced by femtosecond laser filamentation

Filaments created in air by an intense femtosecond laser pulse in the presence of an electric field generate a highly conductive permanent plasma column.

Granular Media and Ballasted Railway Tracks Milieux Granulaires Et Voies Ballastées

Since the beginnings of the railway track, ballasted track is widely employed because of its mechanical properties and its exibility for construction and maintenance but also for their capacity to fulfil the mechanical requirements fixed by the transport of heavy loads at a long distance. The study of the track deterioration is one of the principle assignments in railway engineering, specially for SNCF to preserve a good quality of track and to ensure the comfort and the safety of circulation.

Numerical Simulation and Experimental Investigation of the Side Loading on a High Speed Train

An assessment of train safety whilst simultaneously traveling at high speed and being subjected to strong cross winds requires the knowledge of the aerodynamic load on the train. This situation currently affects the French high speed double decker train (TGV Duplex) that travels on the “TGV Mediterranee” line between Paris and Marseille. For safety reasons, the SNCF has investigated the cross wind sensitivity of the TGV Duplex operating on this line using both reduced scale wind tunnel and hydraulic tank tests and numerical methods. Comparisons between experimental and numerical side and lift forces and lee rail rolling moments acting on the TGV have been made. The leading vehicle experimental pressure distributions have also permitted further comparisons between the experimental and numerical results. Overall, these comparisons showed good agreement between the two sets of results for TGV / wind relative flow angles of 30° or less. Beyond this, the differences between the results are more pronounced with a maximum difference occurring for a relative flow angle of approximately 60°.