On wall pressure fluctuations and their coupling with vortex dynamicsin a separate d–reattache d turbulent flow over a blunt flat plate

This study deals with the numerical predictions through Large-Eddy Simulation ( LES ) of the separated–reattached turbulent flow over a blunt flat plate for analyzing main coherent structure features and theirrelation to the unsteady pressure field. A compressible approach that inherently includes acoustic prop- agation is here followed to describe the relationship between pressure fluctuations and vortex dynam- ics around the separation bubble. The objective of the present work is then to contribute to a betterunderstanding of the coupling between the vortex dynamics and the wall pressure fluctuations. The fil- tered compressible Navier–Stokes equations are then solved with a numerical method that follows a Lax–Wendroffapproach to recover a high accuracy in both time and space. For validations, the present numer- ical results are compared to experimental measurements, coming from both the Pprime laboratory (Sicotel al., 2012) and the literature (Cherry et al., 1984; Kiya and Sasaki, 1985; Tafti and Vanka,1991; Sicotet al., 2012). Our numerical results very well predict mean and fluctuating pressure and velocity fields.Flapping, shedding as well as Kelvin–Helmholtz characteristic frequencies educed by present simulationsare in very good agreement with the experimental values generally admitted. These characteristic modesare also visible on unsteady pressure signatures even far away from the separation. Spectral, POD andEPOD (extended POD) analyses are then applied to these numerical data to enhance the salient featuresof the pressure and velocity fields, especially the unsteady wall pressure in connection with either thevortex shedding or the low frequency shear-layer flapping. A contribution to the understanding of thecoupling between wall pressure fluctuations and eddy vortices is finally proposed

Coherent structures in the boundary layer of a flat thick plate

International audienceWe use POD and EPOD (extended POD) analysis to extract the main features of the flow over a thick flat plate simulated with a LES. Our goal is to better understand the coupling between the velocity field and the surface pressure field. We find that POD modes based on the full velocity and energy fields contain both flapping and shedding frequencies. Pressure modes are found to be uniform in the spanwise direction and the most intense variations take place at the mean reattachment point. Velocity modes educed from the pressure modes with EPOD are seen to correspond to eddies shed by the recirculation bubble. Résumé : Onconsi ere l ecoulementau-dessusd'uneplaqueplanéepaisse.Nousutilisonslasimulationauxgrandeechellesetl'analysePOD/EPODpourcomprendrelecouplageentrelechampdevitesseetlechampdepres-sioalaparoi.LesmodesPODextraitsdelavitessecontiennentdesfréquencescorrespondantauxphénoenesdeflappingetdeshedding.Lesmodesdepressionsontuniformesdansladirectiontransverseetlesvariationslesplusintensessontobservéesaupointderéattachement.Lesmodesdevitesseconstruitapartirdesmodesdepressionavecl'approcheEPODcorrespondenadestourbillonsassociéalabullederecirculation

Mask(s) and European Cinema

The aim of this study is to question the links between Mask, Cinema and Europe. The five films selected are Three Colours: Blue from Kieślowski, Crazy Pierrot from Godard, Strada from Fellini, Death in Venice from Visconti, Wings of Desire from Wenders. These movies exhibit a particular type of mask: the mask without mask. Mask obtained by light or make-up, it seems to express the character’s aspiration for an elsewhere

The aesthetics of Samuel Beckett in the light of his correspondence

L’étude de la correspondance de Samuel Beckett apporte un éclairage inédit sur l’oeuvre d’un auteur qui s’est toujours refusé à accorder entretiens et interviews, objectant son incapacité à s’exprimer vis-à-vis de sa création. Or, s’il n’évoqua jamais celle-ci publiquement, il en dévoile les tenants dans la sphère de l’intime, dont la correspondance et les cahiers allemands se veulent le reflet. Cette correspondance dévoile l’existence d’une esthétique singulière élaborée à l’aune de la réflexion beckettienne vis-à-vis des arts.The study of Samuel Beckett's correspondence sheds new light on the work of an author who always refused to give interviews, claiming that he was unable to express himself in relation to his creation. However, if he never evoked it publicly, he reveals its tenants in the sphere of intimacy, of which the correspondence and the German notebooks are intended to be the reflection. This correspondence reveals the existence of a singular aesthetic elaborated in the light of Becket's reflection on the arts

« Ernest Hamy. Des silex taillés égyptiens aux lampes de Boulogne-sur-Mer »

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Ernest Hamy, des silex taillés égyptiens aux lampes à huile boulonnaises

Au XIXe siècle, plusieurs personnalités ont marqué la société boulonnaise. La plus connue est sans nul doute Auguste Mariette (1821-1881) qui, à partir de 1850, réalise des fouilles au Serapeum de Memphis, en Égypte, puis en de nombreux sites du pays, avant de créer le service des antiquités de l’Égypte et le musée de Boulak, futur musée du Caire. Le monument en forme de pyramide érigé en son honneur à Boulogne retrace les principales fouilles qu’il a dirigées en Égypte Ernest Hamy (1842-1908..

« Les lampes puniques de Carton dans les musées de Saint-Omer et de Boulogne-sur-Mer »

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« Les lampes à huile antiques d’origine locale au Château-Musée de Boulogne-sur-Mer »

International audienceThe Château-Musée of Boulogne-sur-Mer currently accommodates a little more than two hundred lamps. Among them, more than half were found locally, particularly during excavations of necropolises carried out at the end of the XIXth century, and they constitute the subject of the current contribution. If some of them are moulded and imported, a large number, for their most part turned, were produced locally and make up an original corpus which testifies of he adoption of Rome's practices in an outlying part of the Empire.Le Château-Musée de Boulogne-sur-Mer conserve actuellement un peu plus de deux cents lampes. Parmi celles-ci, plus de la moitié ont été trouvées localement, essentiellement lors de fouilles de nécropoles réalisées à la fin du XIXe siècle, et font l’objet de cette étude. Si une partie d’entre elles sont moulées et importées, nombre d’entre elles, la plupart tournées, sont de production locale et constituent un corpus original, qui témoigne de l’adoption des pratiques romaines dans un espace périphérique de l’Empire

Fellini. L'intime et la mer

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