Investigation of Two-Fluid Methods for Large Eddy Simulation of Spray Combustion in Gas Turbines

International audienceAn extension of the large eddy simulation (LES) technique to two-phase reacting flows, required to capture and predict the behavior of industrial burners, is presented. While most efforts reported in the literature to construct LES solvers for two-phase flow focus on Euler–Lagrange formulation, the present work explores a different solution (‘two-fluid’ approach) where an Eulerian formulation is used for the liquid phase and coupled with the LES solver of the gas phase. The equations used for each phase and the coupling terms are presented before describing validation in two simple cases which gather some of the specificities of real combustion chamber: (1) a one-dimensional laminar JP10/air flame and (2) a non-reacting swirled flow where solid particles disperse (Sommerfeld and Qiu, Int. J. Multiphase Flow 19(6):1093–1127, 1993). After these validations, the LES tool is applied to a realistic aircraft combustion chamber to study both a steady flame regime and an ignition sequence by a spark. Results bring new insights into the physics of these complex flames and demonstrate the capabilities of two-fluid LES

Basement‐cover decoupling during the inversion of a hyperextended basin: Insights from the Eastern Pyrenees

International audienceDeformation processes related to early stages of collisional belts, especially the inversion of rifted systems remain poorly constrained, partly because evidence of these processes is usually obliterated during the subsequent collision. The Pyrenean belt resulting from the inversion of a Cretaceous hyperextended rifted margin associated with a HT/LP metamorphism in the Internal Metamorphic Zone (IMZ), is a good example for studying the early stage of orogenic deformation. This study is focused on the Eastern Pyrenees where the relation between inverted Mesozoic rifted basins and their basement are well-preserved. By using maximum temperatures (Tmax) estimated by the Raman Spectroscopy of Carbonaceous Materials geothermometer and structural data, we describe the spatial distribution of the various tectono-metamorphic units. Tmax recorded in the sedimentary cover exposed to the north and to the south of a Paleozoic basement block (Agly massif), exceed 550°C, while the Paleozoic metasediments and their autochthonous Mesozoic cover show Tmax <350°C. The metamorphic sedimentary cover is affected by ductile deformation, while the basement is only affected by brittle deformation. Post-metamorphism breccias are observed between the basement and the metamorphic Accepted Article This article has been accepted for publication and undergone full peer review but has not been through the copyediting, typesetting, pagination and proofreading process, which may lead to differences between this version and the Version of Record. Please cite this article a